Property, Plant and Equipment [Abstract] Schedule of Property, Plant and Equipment Property, Plant and Equipment [Table Text Block] Goodwill and Intangible Assets Disclosure [Abstract] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets [Axis] Indefinite-lived Intangible Assets, Major Class Name [Domain] Indefinite-lived Intangible Assets, Major Class Name [Domain] Trade names and trademarks Trademarks and Trade Names [Member] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets by Major Class [Axis] Finite-Lived Intangible Assets, Major Class Name [Domain] Finite-Lived Intangible Assets, Major Class Name [Domain] Customer relationships Customer Relationships [Member] Leasehold benefits Leasehold Benefits [Member] Leasehold benefits. Developed technology Developed Technology Rights [Member] Non-compete agreements Noncompete Agreements [Member] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Finite-lived intangible assets, gross Finite-Lived Intangible Assets, Gross Accumulated amortization Finite-Lived Intangible Assets, Accumulated Amortization Total Finite-Lived Intangible Assets, Net Indefinite-lived intangible assets, trade names and trademarks Indefinite-Lived Intangible Assets (Excluding Goodwill) Intangible assets, gross Intangible Assets, Gross (Excluding Goodwill) Intangible assets, net Intangible Assets, Net (Excluding Goodwill) Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Award Type [Axis] Award Type [Axis] Equity Award [Domain] Equity Award [Domain] Restricted Stock Restricted Stock [Member] Restricted Stock Units Restricted Stock Units (RSUs) [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding [Roll Forward] Number, Outstanding, at December 31, 2016 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number Number, Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period Number, Vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period Number, Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeited in Period Number, Outstanding, at March 31, 2017 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract] Weighted-Average Fair Value, Outstanding, at December 31, 2016 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value Weighted-Average Fair Value, Granted (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Grants in Period, Weighted Average Grant Date Fair Value Weighted-Average Fair Value, Vested (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Vested in Period, Weighted Average Grant Date Fair Value Weighted-Average Fair Value, Forfeited (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Forfeitures, Weighted Average Grant Date Fair Value Weighted-Average Fair Value, Outstanding, at March 31, 2017 (in dollars per share) Restricted stock units vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] Range [Axis] Range [Axis] Range [Domain] Range [Domain] Minimum Minimum [Member] Maximum Maximum [Member] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Axis] Property, Plant and Equipment, Type [Domain] Property, Plant and Equipment, Type [Domain] Network equipment and computers Technology Equipment [Member] Software Software and Software Development Costs [Member] Leasehold improvements Leasehold Improvements [Member] Office furniture and equipment Furniture and Fixtures [Member] Motor vehicles Vehicles [Member] Buildings Building [Member] Land Land [Member] Capital work in progress Construction in Progress [Member] Property, Plant and Equipment [Line Items] Property, Plant and Equipment [Line Items] Owned Assets: Property, Plant and Equipment, Net, Excluding Capital Leased Assets [Abstract] Owned assets, gross Property, Plant and Equipment, Gross, Excluding Capital Leased Assets Less: Accumulated depreciation and amortization Accumulated Depreciation, Depletion and Amortization, Property, Plant, and Equipment, Excluding Capital Leased Assets Owned Assets, net Property, Plant and Equipment, Net, Excluding Capital Leased Assets Equipment useful life (in years) Property, Plant and Equipment, Useful Life Assets under capital leases: Capital Leases, Balance Sheet, Assets by Major Class, Net [Abstract] Capital leased assets, gross Capital Leased Assets, Gross Less: Accumulated depreciation and amortization Capital Leases, Lessee Balance Sheet, Assets by Major Class, Accumulated Depreciation Assets under capital leases, net Capital Leases, Balance Sheet, Assets by Major Class, Net Property, Plant and Equipment, net Property, Plant and Equipment, Net Restricted Stock and Restricted Stock Units Restricted Stock and Restricted Stock Units [Member] Restricted Stock and Restricted Stock Units [Member] Unrecognized compensation cost Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Share-based Awards Other than Options Cost not yet recognized, period for recognition Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Accounting Policies [Abstract] New Accounting Pronouncements or Change in Accounting Principle [Table] New Accounting Pronouncements or Change in Accounting Principle [Table] Adjustments for New Accounting Pronouncements [Axis] Adjustments for New Accounting Pronouncements [Axis] Type of Adoption [Domain] Type of Adoption [Domain] Accounting Standards Update 2016-09 Accounting Standards Update 2016-09 [Member] Accounting Standards Update 2016-09 [Member] Equity Components [Axis] Equity Components [Axis] Equity Component [Domain] Equity Component [Domain] Additional Paid-in Capital Additional Paid-in Capital [Member] Retained Earnings Retained Earnings [Member] New Accounting Pronouncements or Change in Accounting Principle [Line Items] New Accounting Pronouncements or Change in Accounting Principle [Line Items] Excess tax benefit Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount Effective Income Tax Rate Reconciliation, Share-based Compensation, Excess Tax Benefit, Amount Cumulative effect adjustment Cumulative Effect of New Accounting Principle in Period of Adoption Deferred tax effect Deferred Income Tax Liabilities, Net Commitments and Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Liabilities, Noncurrent [Abstract] Non-current liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Noncurrent [Text Block] Compensation and Retirement Disclosure [Abstract] Expected return on plan assets (as a percent) Defined Benefit Plan Expected Return On Plan Assets Percentage Defined Benefit Plan Expected Return On Plan Assets Percentage Discretionary contributions towards 401(k) Plan, maximum (as a percent) Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Discretionary contributions to 401 (k) plans Defined Contribution Plan, Employer Discretionary Contribution Amount Contributions to various defined contribution plans Defined Contribution Plan, Cost Recognized Income Tax Disclosure [Abstract] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward] Balance as of January 1, 2017 Unrecognized Tax Benefits Increases related to prior year tax positions Unrecognized Tax Benefits, Increase Resulting from Prior Period Tax Positions Decreases related to prior year tax positions Unrecognized Tax Benefits, Decrease Resulting from Prior Period Tax Positions Increases related to current year tax positions Unrecognized Tax Benefits, Increase Resulting from Current Period Tax Positions Decreases related to current year tax positions Unrecognized Tax Benefits, Decrease Resulting from Current Period Tax Positions Effect of exchange rate changes Unrecognized Tax Benefits, Increase Resulting from Foreign Currency Translation Balance as of June 30, 2017 Segment Reporting [Abstract] Number of operating segments Number of Operating Segments Number of operating segments, operations management Number of Operating Segments, Operations Management Services Number of Operating Segments, Operations Management Services Number of operating segments, finance and accounting Number of Operating Segments, Finance and Accounting Services Number of Operating Segments, Finance and Accounting Services Number of operating segments, company provides operations management services Number of Operating Segments, Company Provides Operations Management Services Number of Operating Segments, Company Provides Operations Management Services Number of non-operations management services Number of Operating Segments, Non-Operations Management Services Number of Operating Segments, Non-Operations Management Services Number of reportable segments Number of Reportable Segments Employee Stock Option Employee Stock Option [Member] Unrecognized compensation cost, unvested options Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options Number of options, granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross Total grant date fair value of option vested in period Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value Derivative Instruments and Hedging Activities Disclosure [Abstract] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Foreign Currency Exchange Contracts Foreign Exchange Contract [Member] Hedging Designation [Axis] Hedging Designation [Axis] Hedging Designation [Domain] Hedging Designation [Domain] Derivatives Designated as Hedging Instruments Designated as Hedging Instrument [Member] Derivatives not Designated as Hedging Instruments Not Designated as Hedging Instrument [Member] Balance Sheet Location [Axis] Balance Sheet Location [Axis] Balance Sheet Location [Domain] Balance Sheet Location [Domain] Other current assets Other Current Assets [Member] Other assets Other Assets [Member] Accrued expenses and other current liabilities Accrued Expenses And Other Current Liabilities [Member] Accrued expenses and other current liabilities. Non-current liabilities Noncurrent Liabilities [Member] Noncurrent Liabilities [Member] Derivatives, Fair Value [Line Items] Derivatives, Fair Value [Line Items] Foreign currency exchange contracts, asset Derivative Asset, Fair Value, Gross Asset Foreign currency exchange contracts, liability Derivative Liability, Fair Value, Gross Liability Summary of Significant Accounting Policies Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block] Payables and Accruals [Abstract] Schedule of Accrued Expenses and Other Current Liabilities Schedule of Accrued Liabilities [Table Text Block] Fair Value Disclosures [Abstract] Assets and Liabilities Measured at Fair Value Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block] Statement of Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] Net income Net Income (Loss) Attributable to Parent Adjustments to reconcile net income to net cash provided by operating activities: Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract] Depreciation and amortization Depreciation, Depletion and Amortization Stock-based compensation expense Share-based Compensation Unrealized gain on short term investments Unrealized Gain (Loss) on Investments Change in fair value of earn-out consideration Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability Unrealized foreign exchange loss/(gain) Foreign Currency Transaction Gain (Loss), Unrealized Deferred income tax (benefit)/expense Deferred Income Tax Expense (Benefit) Others, net Other Noncash Income (Expense) Change in operating assets and liabilities: Increase (Decrease) in Operating Capital [Abstract] Restricted cash Increase (Decrease) in Restricted Cash for Operating Activities Accounts receivable Increase (Decrease) in Accounts Receivable Prepaid expenses and other current assets Increase (Decrease) in Prepaid Expense and Other Assets Accounts payable Increase (Decrease) in Accounts Payable Deferred revenue Increase (Decrease) in Deferred Revenue Accrued employee costs Increase (Decrease) in Other Employee-Related Liabilities Accrued expenses and other liabilities Increase (Decrease) in Other Accounts Payable and Accrued Liabilities Advance income tax, net Increase (Decrease) in Income Taxes Payable Other assets Increase (Decrease) in Other Operating Assets Net cash provided by operating activities Net Cash Provided by (Used in) Operating Activities Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchase of property, plant and equipment Payments to Acquire Property, Plant, and Equipment Purchase of investments Payments to Acquire Investments Proceeds from redemption of investments Proceeds from Sale, Maturity and Collection of Investments Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities Cash flows from financing activities: Net Cash Provided by (Used in) Financing Activities, Continuing Operations [Abstract] Principal payments on capital lease obligations Repayments of Long-term Capital Lease Obligations Repayments of borrowings Repayments of Debt Acquisition of treasury stock Payments for Repurchase of Common Stock Proceeds from exercise of stock options Proceeds from Stock Options Exercised Net cash used for financing activities Net Cash Provided by (Used in) Financing Activities Effect of exchange rate changes on cash and cash equivalents Effect of Exchange Rate on Cash and Cash Equivalents Net decrease in cash and cash equivalents Cash and Cash Equivalents, Period Increase (Decrease) Cash and cash equivalents, beginning of period Cash and Cash Equivalents, at Carrying Value Cash and cash equivalents, end of period Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] Cumulative currency translation adjustments Accumulated Other Comprehensive Income (Loss), Foreign Currency Translation Adjustment, Net of Tax Unrealized gain on cash flow hedges, net of taxes of $3,896 and $1,207 Accumulated Other Comprehensive Income (Loss), Cumulative Changes in Net Gain (Loss) from Cash Flow Hedges, Effect Net of Tax Retirement benefits, net of taxes of ($295) and ($342) Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Unrealized gain / (loss) on cash flow hedges, taxes Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Tax Portion Accumulated Other Comprehensive Income Loss Cumulative Changes In Net Gain Loss From Cash Flow Hedges Effect Tax Portion Retirement benefits, taxes Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Post Retirement Plans Tax Portion Accumulated Other Comprehensive Income Loss Defined Benefit Pension And Other Post Retirement Plans Tax Portion Accumulated Other Comprehensive Loss Comprehensive Income (Loss) Note [Text Block] Performance Based Stock Awards Performance Based Stock Awards [Member] Performance Based Stock Awards [Member] Goodwill and Intangible Assets Goodwill and Intangible Assets Disclosure [Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Other Income and Expenses [Abstract] Interest and dividend income Investment Income, Interest and Dividend Gain on mutual fund investments Gain (Loss) on Investments Change in fair value of earn-out consideration Other, net Other Miscellaneous Nonoperating Income (Expense) Other Miscellaneous Nonoperating Income (Expense) Other income, net Other Nonoperating Income (Expense) Other Income, net Interest and Other Income [Text Block] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] Related Party Transactions [Abstract] Revenue from related party Revenue from Related Parties Accounts receivable from related party Accounts Receivable, Related Parties Derivative instruments Derivative Instruments and Hedges, Liabilities, Noncurrent Unrecognized tax benefits Liability for Uncertainty in Income Taxes, Noncurrent Deferred rent Deferred Rent Credit, Noncurrent Retirement benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Others Other Liabilities, Noncurrent Non-current liabilities Liabilities, Other than Long-term Debt, Noncurrent Income Taxes Income Tax Disclosure [Text Block] Equity [Abstract] Class of Treasury Stock [Table] Class of Treasury Stock [Table] Share Repurchase Program [Axis] Share Repurchase Program [Axis] Share Repurchase Program [Domain] Share Repurchase Program [Domain] 2014 Repurchase Program Two Thousand Fourteen Repurchase Program [Member] Two thousand fourteen repurchase program. 2017 Repurchase Program Two Thousand Seventeen Repurchase Program [Member] Two Thousand Seventeen Repurchase Program [Member] 2014 and 2017 Repurchase Program Two Thousand Fourteen and Two Thousand Seventeen Repurchase Program [Member] Two Thousand Fourteen and Two Thousand Seventeen Repurchase Program [Member] Equity, Class of Treasury Stock [Line Items] Equity, Class of Treasury Stock [Line Items] Number of classes of common stock outstanding Number Of Classes Of Common Stock Outstanding Number Of Classes Of Common Stock Outstanding Acquisition of restricted stock from employees in connection with withholding tax payments (in shares) Shares Paid for Tax Withholding for Share Based Compensation Withholding tax payments related to the vesting of restricted stock for total consideration Payments Related to Tax Withholding for Share-based Compensation Weighted average purchase price per share prior to the vesting date (in dollars per share) Accelerated Share Repurchases, Final Price Paid Per Share Repurchase of common stock authorized by board of directors up to Stock Repurchase Program, Authorized Amount Stock repurchase program, period start (year) Stock Repurchase Program Period Start Stock repurchase program period start. Stock repurchase program, period end (year) Stock Repurchase Program Period End Stock repurchase program period end. Authorized increase in repurchase amount Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period Authorized increase in repurchase amount, 2018 Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period, Year Two Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period, Year Two Authorized increase in repurchase amount, 2019 Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period, Year Three Stock Repurchase Program, Authorized Increase in Repurchase Amount Per Period, Year Three Common stock shares purchased under the repurchase program (in shares) Treasury Stock, Shares, Acquired Common stock aggregate purchase price including commissions Common Stock Aggregate Purchase Price Including Commission Common stock aggregate purchase price including commission. Common stock average purchase price per share (in dollars per share) Treasury Stock Acquired, Average Cost Per Share Schedule of Accumulated Other Comprehensive Loss Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] BPM and Related Services BPM and Related Services [Member] BPM and Related Services [Member] Analytics Services Analytics Services [Member] Analytics Services [Member] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Insurance Insurance [Member] Insurance [Member] Healthcare Healthcare [Member] Healthcare [Member] Travel, Transportation and Logistics Travel, Transportation and Logistics [Member] Travel, Transportation and Logistics [Member] Finance and Accounting Finance and Accounting [Member] Finance and Accounting [Member] All Other Other Operations Management [Member] Other Operations Management [Member] Analytics Analytics And Business Transformation [Member] Analytics and business transformation. Revenues and cost of revenues for Company's reportable segments [Line Items] Revenue from External Customer [Line Items] Revenues, net Sales Revenue, Services, Net Cost of revenues (exclusive of depreciation and amortization) Cost of Services, Excluding Depreciation, Depletion, and Amortization Gross profit Gross Profit Operating expenses Operating Expenses Foreign exchange gain, interest expense and other income, net Nonoperating Income (Expense) Income tax expense Income Tax Expense (Benefit) Net income Number of operating segments, industry focused Number of Operating Segments, Industry Focused Number of Operating Segments, Industry Focused Number of capability operating segments Net Gratuity Cost Schedule of Net Benefit Costs [Table Text Block] Change in Plan Assets Schedule of Changes in Fair Value of Plan Assets [Table Text Block] Service cost Defined Benefit Plan, Service Cost Interest cost Defined Benefit Plan, Interest Cost Expected return on plan assets Defined Benefit Plan, Expected Return on Plan Assets Amortization of Actuarial loss Defined Benefit Plan, Amortization of Gains (Losses) Net gratuity cost Defined Benefit Plan, Net Periodic Benefit Cost Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Other current assets Other Current Assets [Text Block] Derivative instruments Derivative Asset, Current Advances to suppliers Prepaid Supplies Receivables from statutory authorities Service Taxes Receivable, Current Service Taxes Receivable, Current Others Other Assets, Miscellaneous, Current Other current assets Other Assets, Current Purchase commitments, net of advances Purchase Commitment, Remaining Minimum Amount Committed Export-oriented units established (as a percent) Export Oriented Units Established Percentage Export oriented units established percentage. Transfer pricing issues starting period (year) Transfer Pricing Issues Starting Period Transfer pricing issues starting period. Transfer pricing issues ending period (year) Transfer Pricing Issues Ending Period Transfer pricing issues ending period. Permanent establishment issues starting period (year) Transfer Pricing Establishment Issues Starting Period Transfer pricing establishment issues starting period. Permanent establishment issues ending period (year) Transfer Pricing Establishment Issues Ending Period Transfer pricing establishment issues ending period. Aggregate disputed amount amount related to transfer pricing and permanent establishment Aggregate Disputed Amount Related to Transfer Pricing and Permanent Establishment Aggregate disputed amount related to transfer pricing and permanent establishment Total bank guarantees and deposits in respect of contingencies Total Bank Guarantees And Deposits In Respect Of Contingencies Total Bank Guarantees and Deposits in Respect of Contingencies Amounts paid as deposits in respect of contingencies Amounts Paid As Deposits In Respect Of Contingencies Amounts paid as deposits in respect of Contingencies. Bank guarantee issued Bank Guarantee Issued Bank Guarantee Issued Accrued expenses and other current liabilities Accounts Payable, Accrued Liabilities, and Other Liabilities Disclosure, Current [Text Block] Fair Value Measurements Fair Value, Measurement Inputs, Disclosure [Text Block] 2015 Stock Options Plan Two Thousand Fifteen Stock Options Plan [Member] Two Thousand Fifteen Stock Options Plan [Member] Number of shares available for grant Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant 2018 Finite-Lived Intangible Assets, Amortization Expense, Next Rolling Twelve Months 2019 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Two 2020 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Three 2021 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Four 2022 and thereafter Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Five Leases [Abstract] 2018 Capital Leases, Future Minimum Payments, Next Rolling Twelve Months 2019 Capital Leases, Future Minimum Payments, Due in Rolling Year Two 2020 Capital Leases, Future Minimum Payments, Due in Rolling Year Three 2021 Capital Leases, Future Minimum Payments, Due in Rolling Year Four Total minimum lease payments Capital Leases, Future Minimum Payments Due Less: amount representing interest Capital Leases, Future Minimum Payments, Interest Included in Payments Present value of minimum lease payments Capital Leases, Future Minimum Payments, Present Value of Net Minimum Payments Less: current portion Capital Lease Obligations, Current Long term capital lease obligation Capital Lease Obligations, Noncurrent Schedule of Other Current Assets Schedule of Other Current Assets [Table Text Block] Summary of Fair Value of Foreign Currency Exchange Contracts Schedule of Foreign Exchange Contracts, Statement of Financial Position [Table Text Block] Summary of Effect of Foreign Currency Exchange Contracts on Consolidated Statements of Income Derivative Instruments, Gain (Loss) [Table Text Block] Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Short-term investments Short-term Investments Restricted cash Restricted Cash and Cash Equivalents, Current Accounts receivable, net Accounts Receivable, Net, Current Prepaid expenses Prepaid Expense, Current Advance income tax, net Prepaid Taxes Other current assets Total current assets Assets, Current Property, plant and equipment, net Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Deferred taxes, net Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Intangible assets, net Goodwill Goodwill Other assets Other Assets, Noncurrent Total assets Assets Liabilities and Equity Liabilities and Equity [Abstract] Current liabilities: Liabilities, Current [Abstract] Accounts payable Accounts Payable, Current Short-term borrowings Short-term Debt Deferred revenue Deferred Revenue, Current Accrued employee cost Employee-related Liabilities, Current Accrued expenses and other current liabilities Accrued Liabilities, Current Current portion of capital lease obligations Total current liabilities Liabilities, Current Long term borrowings Long-term Debt, Excluding Current Maturities Capital lease obligations, less current portion Non-current liabilities Total liabilities Liabilities Commitments and contingencies (See Note 21) Commitments and Contingencies Preferred stock, $0.001 par value; 15,000,000 shares authorized, none issued Preferred Stock, Value, Issued Stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock, $0.001 par value; 100,000,000 shares authorized, 36,252,428 shares issued and 33,691,731 shares outstanding as of June 30, 2017 and 35,699,819 shares issued and 33,628,109 shares outstanding as of December 31, 2016 Common Stock, Value, Issued Additional paid-in capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Total including shares held in treasury Stockholders Equity Including Shares Held In Treasury Total stockholders' equity including shares held in treasury. Less: 2,560,697 shares as of June 30, 2017 and 2,071,710 shares as of December 31, 2016, held in treasury, at cost Treasury Stock, Value Stockholders' equity Stockholders' Equity Attributable to Parent Non-controlling interest Stockholders' Equity Attributable to Noncontrolling Interest Total equity Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest Total liabilities and equity Liabilities and Equity Derivatives and Hedge Accounting Derivative Instruments and Hedging Activities Disclosure [Text Block] Fair Value Measurements, Recurring and Nonrecurring [Table] Fair Value Measurements, Recurring and Nonrecurring [Table] Measurement Frequency [Axis] Measurement Frequency [Axis] Fair Value, Measurement Frequency [Domain] Fair Value, Measurement Frequency [Domain] Recurring Fair Value, Measurements, Recurring [Member] Fair Value, Hierarchy [Axis] Fair Value, Hierarchy [Axis] Fair Value Hierarchy [Domain] Fair Value Hierarchy [Domain] Level 1 Fair Value, Inputs, Level 1 [Member] Level 2 Fair Value, Inputs, Level 2 [Member] Level 3 Fair Value, Inputs, Level 3 [Member] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] Assets Assets, Fair Value Disclosure [Abstract] Money market and mutual funds Money Market And Mutual Fund Fair Value Disclosure Money market and mutual fund fair value disclosure. Derivative financial instruments Foreign Currency Contract, Asset, Fair Value Disclosure Total Assets, Fair Value Disclosure Liabilities Liabilities, Fair Value Disclosure [Abstract] Derivative financial instruments Foreign Currency Contracts, Liability, Fair Value Disclosure Total Financial and Nonfinancial Liabilities, Fair Value Disclosure Statement of Comprehensive Income [Abstract] Unrealized (loss)/gain on effective cash flow hedges, taxes Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Tax Retirement benefits, taxes Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Tax Realized loss/(gain) on cash flow hedges, taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Tax Retirement benefits, taxes Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Tax Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding [Roll Forward] Number of Options, Outstanding, at December 31, 2016 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Number of Options, Granted (in shares) Number of Options, Exercised (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Exercises in Period Number of Options, Forfeited (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Forfeitures in Period Number of Options, Outstanding, at June 30, 2017 (in shares) Number of Options, Vested and exercisable at June 30, 2017 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Number Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price [Abstract] Weighted-Average Exercise Price, Outstanding, at December 31, 2016 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Exercise Price Weighted-Average Exercise Price, Granted (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price Weighted-Average Exercise Price, Exercised (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Exercises in Period, Weighted Average Exercise Price Weighted-Average Exercise Price, Forfeited (in dollars per share) Share-based Compensation Arrangements by Share-based Payment Award, Options, Forfeitures in Period, Weighted Average Exercise Price Weighted-Average Exercise Price, Outstanding, at June 30, 2017 (in dollars per share) Weighted Average Exercise Price, Vested and exercisable at June 30, 2017 (in dollars per share) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Weighted Average Exercise Price Aggregate Intrinsic Value, Outstanding Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Intrinsic Value Weighted-Average Remaining Contractual Life (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Weighted Average Remaining Contractual Term Aggregate Intrinsic Value, Vested and exercisable at June 30, 2017 Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Exercisable, Aggregate Intrinsic Value Weighted-Average Remaining Contractual Life, Vested and exercisable at June 30, 2017 (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Schedule of Goodwill [Table] Schedule of Goodwill [Table] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Beginning Balance Acquisitions Goodwill, Acquired During Period Currency translation adjustments Goodwill, Foreign Currency Translation Gain (Loss) Ending Balance Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Acquired Finite-Lived Intangible Assets [Line Items] Acquired Finite-Lived Intangible Assets [Line Items] Amortization expense Amortization of Intangible Assets Remaining amortization period (in years) Finite-Lived Intangible Assets, Remaining Amortization Period Leases Leases of Lessee Disclosure [Text Block] Basis of Preparation Basis of Accounting, Policy [Policy Text Block] Principles of Consolidation Consolidation, Policy [Policy Text Block] Use of Estimates Use of Estimates, Policy [Policy Text Block] Recent Accounting Pronouncements New Accounting Pronouncements, Policy [Policy Text Block] Summary of Company's Goodwill Schedule of Goodwill [Table Text Block] Summary of Company's Intangible Assets Schedule Of Finite Lived And Indefinite Lived Intangible Assets By Major Class [Table Text Block] Schedule Of Finite Lived And Indefinite Lived Intangible Assets By Major Class [Table Text Block] Estimated Amortization of Intangible Assets Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block] Capital Structure Stockholders' Equity Note Disclosure [Text Block] Summary of Non-Current Liabilities Other Noncurrent Liabilities [Table Text Block] Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Cost of revenue Cost of Sales [Member] General and administrative expenses General and Administrative Expense [Member] Selling and marketing expenses Selling and Marketing Expense [Member] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Share-based Compensation Arrangement by Share-based Payment Award, Compensation Cost [Line Items] Stock-based compensation expenses Allocated Share-based Compensation Expense Future Minimum Lease Payments under Capital Leases Schedule of Future Minimum Lease Payments for Capital Leases [Table Text Block] Future Minimum Lease Payments under Non-Cancelable Operating Lease Agreements Schedule of Future Minimum Rental Payments for Operating Leases [Table Text Block] Summary of Other Income, net Interest and Other Income [Table Text Block] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Hedging Relationship [Axis] Hedging Relationship [Axis] Hedging Relationship [Domain] Hedging Relationship [Domain] Derivatives in Cash Flow Hedging Relationships Cash Flow Hedging [Member] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Foreign exchange contracts outstanding Derivative, Notional Amount Net derivative losses which could be reclassified into earnings within the next 12 months Cash Flow Hedge Gain (Loss) to be Reclassified within Twelve Months Maximum outstanding term of cash flow hedges (in months) Maximum Length of Time Hedged in Cash Flow Hedge Gain/(losses) that reclassified from AOCI into earning for discontinued hedging transactions Gain (Loss) on Discontinuation of Cash Flow Hedge Due to Forecasted Transaction Probable of Not Occurring, Net Revenue Based PRSUs Revenue Based Performance Restricted Stock Units [Member] Revenue Based Performance Restricted Stock Units [Member] Market Condition Based PRSUs Market Condition Based Performance Restricted Stock Units [Member] Market Condition Based Performance Restricted Stock Units [Member] Revenues and Cost of Revenues for Company's Reportable Segments Schedule of Segment Reporting Information, by Segment [Table Text Block] Revenues Based on Geographical Information Revenue from External Customers by Geographic Areas [Table Text Block] Property, Plant and Equipment based on Geographical Information Long-lived Assets by Geographic Areas [Table Text Block] Accrued expenses Accrued Expenses Current Accrued expenses. Derivative instruments Derivative Instruments and Hedges, Liabilities Client liability account Payables to Customers Others Other Liabilities, Current Accrued expenses and other current liabilities Summary of Activity Related to Gross Unrecognized Tax Benefits Schedule Of Unrecognized Tax Benefits Table [Table Text Block] A summary of unrecognized tax benefits recognized during the period. An unrecognized tax benefit is the difference between a tax position taken in a tax return and the amounts recognized in the financial statements for which it is more likely than not, based on the technical merits of the position, that the tax position will not be sustained upon examination. Related Party Disclosures Related Party Transactions Disclosure [Text Block] Costs Related to Company's Stock-Based Compensation Plan Schedule of Employee Service Share-based Compensation, Allocation of Recognized Period Costs [Table Text Block] Stock Based Compensation Stock Option Activity Schedule of Share-based Compensation, Stock Options, Activity [Table Text Block] Restricted Stock Activity Under Company's Stock Plans Disclosure of Share-based Compensation Arrangements by Share-based Payment Award [Table Text Block] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Schedule of Revenues from External Customers and Long-Lived Assets [Table] Geographical [Axis] Geographical [Axis] Geographical [Domain] Geographical [Domain] India INDIA United States UNITED STATES Philippines PHILIPPINES Rest of World Rest Of World [Member] Rest of World. Revenues from External Customers and Long-Lived Assets [Line Items] Revenues from External Customers and Long-Lived Assets [Line Items] Depreciation and amortization expense Depreciation Software development costs Capitalized Computer Software, Gross Capitalized software development costs, accumulated amortization Capitalized Computer Software, Accumulated Amortization Debt Disclosure [Abstract] Line of Credit Facility [Table] Line of Credit Facility [Table] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Revolving Credit Facility Revolving Credit Facility [Member] Credit Facilities [Line Items] Line of Credit Facility [Line Items] Credit facility capacity Line of Credit Facility, Maximum Borrowing Capacity Credit facility expiration date Line of Credit Facility, Expiration Date Credit facility capacity, outstanding Long-term Line of Credit Line of credit interest rate during period (as a percent) Line of Credit Facility, Interest Rate During Period Unamortized debt issuance costs Debt Issuance Costs, Net Interest coverage ratio, minimum Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Debt Instrument, Covenant, Interest Coverage Ratio, Minimum Leverage ratio, minimum Debt Instrument, Covenant, Leverage Ratio, Minimum Debt Instrument, Covenant, Leverage Ratio, Minimum Numerators: Net Income (Loss) Attributable to Parent [Abstract] Denominators: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic weighted average common shares outstanding Weighted Average Number of Shares Outstanding, Basic Dilutive effect of share based awards (in shares) Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements Diluted weighted average common shares outstanding Weighted Average Number of Shares Outstanding, Diluted Earnings Per Share: Earnings Per Share, Basic and Diluted [Abstract] Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Weighted average common shares considered anti-dilutive in computing diluted earnings per share Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized Preferred Stock, Shares Authorized Preferred stock, shares issued Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized Common Stock, Shares Authorized Common stock, shares issued Common Stock, Shares, Issued Common stock, shares outstanding Common Stock, Shares, Outstanding Treasury stock (in shares) Treasury Stock, Shares Foreign exchange gain/(loss) Foreign Currency Gain (Loss) [Member] Gain/(loss) recognized in AOCL on derivative - Effective portion Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Gain/(loss) reclassified from AOCL to foreign exchange gain/(loss) - Effective portion Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Gain/(loss) recognized in foreign exchange gain/(loss) - Ineffective portion Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Gain/(loss) recognized in foreign exchange gain/(loss) Derivative, Gain (Loss) on Derivative, Net Other comprehensive income: Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized (loss)/gain on effective cash flow hedges, net of taxes $1,085, ($376), $3,036 and $27, respectively Other Comprehensive Income (Loss), Unrealized Gain (Loss) on Derivatives Arising During Period, Net of Tax Foreign currency translation adjustment Other Comprehensive Income (Loss), Foreign Currency Transaction and Translation Adjustment, Net of Tax Retirement benefits, net of taxes nil, $15, nil and $20, respectively Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net Unamortized Gain (Loss) Arising During Period, Net of Tax Reclassification adjustments Other Comprehensive (Income) Loss, Pension and Other Postretirement Benefit Plans, Adjustment, Net of Tax [Abstract] Realized gain on cash flow hedges, net of taxes ($156), ($156), ($347) and ($181), respectively(1) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Retirement benefits, net of taxes $40, $1, $47 and $2, respectively(2) Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI, Pension and Other Postretirement Benefit Plans, for Net Gain (Loss), Net of Tax Total other comprehensive income/(loss) Other Comprehensive Income (Loss), Net of Tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Borrowings Debt Disclosure [Text Block] Document And Entity Information [Abstract] Document and entity information. Entity Registrant Name Entity Registrant Name Entity Central Index Key Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Document Type Document Type Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Trading Symbol Trading Symbol Document Fiscal Period Focus Document Fiscal Period Focus Amendment Flag Amendment Flag Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Property, Plant and Equipment Property, Plant and Equipment Disclosure [Text Block] Rent expense under both cancelable and non-cancelable operating leases Operating Leases, Rent Expense, Net Deferred rent Deferred Rent Credit Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] United States United Kingdom UNITED KINGDOM Rest of World Non-US Non-US [Member] Revenues, net Segment and Geographical Information Segment Reporting Disclosure [Text Block] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Defined Benefit Plan, Change in Fair Value of Plan Assets [Roll Forward] Plan assets at January 1, 2017 Defined Benefit Plan, Fair Value of Plan Assets Actual return Defined Benefit Plan, Actual Return on Plan Assets Employer contribution Defined Benefit Plan, Contributions by Employer Benefits paid Defined Benefit Plan Benefits Paid Through Plan Assets Defined benefit plan benefits paid through plan assets. Effect of exchange rate changes Defined Benefit Plan, Foreign Currency Exchange Rate Changes, Plan Assets Plan assets at June 30, 2017 Effective tax rate Effective Income Tax Rate Reconciliation, Percent Discrete item Uncertain tax position, tax expense (benefit) Effective Income Tax Rate Reconciliation, Tax Settlement, Amount Uncertain tax position, interest amount, tax expense (benefit) Effective Income Tax Rate Reconciliation, Tax Settlement, Interest Amount Effective Income Tax Rate Reconciliation, Tax Settlement, Interest Amount Reversal of earn-out liability Effective Income Tax Rate Reconciliation, Earn-out Liability Effective Income Tax Rate Reconciliation, Earn-out Liability, Amount Unrecognized tax benefits Interest expense Income Tax Examination, Interest Expense Accrued interest and penalties Unrecognized Tax Benefits, Income Tax Penalties and Interest Accrued Income Statement [Abstract] Operating expenses: Operating Expenses [Abstract] General and administrative expenses General and Administrative Expense Selling and marketing expenses Selling and Marketing Expense Depreciation and amortization Depreciation, Depletion and Amortization, Nonproduction Total operating expenses Income from operations Operating Income (Loss) Foreign exchange gain, net Foreign Currency Transaction Gain (Loss), before Tax Interest expense Interest Expense Other income, net Income before income tax expense Income (Loss) from Continuing Operations before Income Taxes, Noncontrolling Interest Earnings per share: Weighted-average number of shares used in computing earnings per share: Basic (in shares) Diluted (in shares) 2018 Operating Leases, Future Minimum Payments, Next Rolling Twelve Months 2019 Operating Leases, Future Minimum Payments, Due in Rolling Year Two 2020 Operating Leases, Future Minimum Payments, Due in Rolling Year Three 2021 Operating Leases, Future Minimum Payments, Due in Rolling Year Four 2022 Operating Leases, Future Minimum Payments, Due in Rolling Year Five 2023 and thereafter Operating Leases, Future Minimum Payments, Due in Rolling after Year Five Total operating lease payments Operating Leases, Future Minimum Payments Due