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 Percentage of discretionary contributions towards 401(k) Plan, Maximum (as a percent) Defined Contribution Plan, Maximum Annual Contributions Per Employee, Percent Company's contribution to the 401(k) Plan Defined Contribution Plan, Cost Recognized Contribution to various defined contribution plans Defined Contribution Plan, Employer Discretionary Contribution Amount Accounting Policies [Abstract] Summary of Significant Accounting Policies Significant Accounting Policies [Text Block] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Stock Based Compensation Disclosure of Compensation Related Costs, Share-based Payments [Text Block] Business Combinations [Abstract] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] Schedule of Acquired Finite-Lived Intangible Asset by Major Class [Table] 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] Trade names and trademarks Trademarks and Trade Names [Member] 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 Indefinite lived trade names and trademarks Indefinite-Lived Intangible Assets (Excluding Goodwill) Segment Reporting [Abstract] 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] United States UNITED STATES United Kingdom UNITED KINGDOM 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] Revenues, net Revenues [Abstract] Revenues, net Sales Revenue, Services, Net Commitments and Contingencies Disclosure [Abstract] Purchase commitments, net of advances Other Commitment, Due in Next Twelve Months 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 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] 2015 Stock Options Plan Two Thousand Fifteen Stock Options Plan [Member] Two Thousand Fifteen Stock Options Plan [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Number of shares available for grant (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Available for Grant Leases [Abstract] Rent expense under both cancelable and non-cancelable operating leases Operating Leases, Rent Expense, Net Deferred rent Deferred Rent Credit Restricted Stock Units Restricted Stock Units (RSUs) [Member] Performance Based Stock Awards Performance Based Stock Awards [Member] Performance Based Stock Awards [Member] 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] Commitments and Contingencies Commitments and Contingencies Disclosure [Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments, Gain (Loss) [Table] Derivative Instruments, Gain (Loss) [Table] Derivative Instrument [Axis] Derivative Instrument [Axis] Derivative Contract [Domain] Derivative Contract [Domain] Foreign Currency Exchange Contracts Foreign Exchange Contract [Member] Income Statement Location [Axis] Income Statement Location [Axis] Income Statement Location [Domain] Income Statement Location [Domain] Foreign exchange gain/(loss) Foreign Currency Gain (Loss) [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] 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] Amount of Gain/(Loss) Recognized in AOCI on Derivative (Effective Portion) Derivative Instruments, Gain (Loss) Recognized in Other Comprehensive Income (Loss), Effective Portion, Net Amount of Gain/(Loss) Reclassified from AOCI into Income (Effective Portion) Derivative Instruments, Gain (Loss) Reclassified from Accumulated OCI into Income, Effective Portion, Net Amount of Gain/(Loss) Recognized in Income on Derivative (Ineffective Portion and Amount Excluded from Effectiveness Testing) Derivative Instruments, Gain (Loss) Recognized in Income, Ineffective Portion and Amount Excluded from Effectiveness Testing, Net Amount of Gain/(Loss) Recognized in Income on Derivatives Derivative, Gain (Loss) on Derivative, Net Statement of Financial Position [Abstract] Assets Assets [Abstract] Current assets: Assets, Current [Abstract] Cash and cash equivalents Cash and Cash Equivalents, at Carrying Value 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 Other Assets, Current Total current assets Assets, Current Fixed assets, net Property, Plant and Equipment, Net Restricted cash Restricted Cash and Cash Equivalents, Noncurrent Deferred tax assets, net Deferred Tax Assets, Net of Valuation Allowance, Noncurrent Intangible assets, net Intangible Assets, Net (Excluding Goodwill) 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 Capital Lease Obligations, Current Total current liabilities Liabilities, Current Long term borrowings Long-term Debt, Excluding Current Maturities Capital lease obligations, less current portion Capital Lease Obligations, Noncurrent Non-current liabilities Liabilities, Other than Long-term Debt, Noncurrent Total liabilities Liabilities Commitments and contingencies Commitments and Contingencies Preferred stock, $0.001 par value; 15,000,000 shares authorized, none issued Preferred Stock, Value, Issued ExlService Holdings, Inc. stockholders’ equity: Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest [Abstract] Common stock, $0.001 par value; 100,000,000 shares authorized, 35,252,413 shares issued and 33,409,249 shares outstanding as of March 31, 2016 and 34,781,201 shares issued and 33,091,223 shares outstanding as of December 31, 2015 Common Stock, Value, Issued Additional paid-in-capital Additional Paid in Capital, Common Stock Retained earnings Retained Earnings (Accumulated Deficit) Accumulated other comprehensive loss Accumulated Other Comprehensive Income (Loss), Net of Tax Total including shares held in treasury Stockholders Equity Including Shares Held In Treasury Total stockholders' equity including shares held in treasury. Less: 1,843,164 shares as of March 31, 2016 and 1,689,978 shares as of December 31, 2015, held in treasury, at cost Treasury Stock, Value ExlService Holdings, Inc. 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 2017 Finite-Lived Intangible Assets, Amortization Expense, Next Rolling Twelve Months 2018 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Two 2019 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Three 2020 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Four 2021 Finite-Lived Intangible Assets, Amortization Expense, Rolling Year Five Accumulated Other Comprehensive Income (Loss), Net of Tax [Abstract] 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 $1,035 and $657 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 ($194) and ($201) Accumulated Other Comprehensive Income (Loss), Pension and Other Postretirement Benefit Plans, Net of Tax Accumulated other comprehensive loss 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 Number of operating segments merged Number Of Operating Segments Merged Number Of Operating Segments Merged Derivatives and Hedge Accounting Derivative Instruments and Hedging Activities Disclosure [Text Block] Geographical Information Geographical Information [Text Block] This element may be used to disclose in the entity's country of domicile and its entirety the names of foreign countries from which revenue is material and the amount of revenue from external customers attributed to those countries. An entity may also provide subtotals of geographic information about groups of countries. This element also include amount of long-lived assets other than financial instruments, long-term customer relationships of a financial institution, mortgage and other servicing rights, deferred policy acquisition costs, and deferred tax assets, located in the entity's country of domicile and in foreign countries in total in which the entity holds assets. India INDIA Philippines PHILIPPINES Fixed assets, net Property, Plant and Equipment, Net [Abstract] 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] 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, 2015 (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, 2016 (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, 2015 (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, 2016 (in dollars per share) Leases Leases of Lessee Disclosure [Text Block] Property, Plant and Equipment [Abstract] Depreciation and amortization expense Depreciation Schedule of Goodwill [Table] Schedule of Goodwill [Table] Products and Services [Axis] Products and Services [Axis] Products and Services [Domain] Products and Services [Domain] Operations Management Operations Management [Member] Operations management. Analytics Analytics And Business Transformation [Member] Analytics and business transformation. Business Acquisition [Axis] Business Acquisition [Axis] Business Acquisition, Acquiree [Domain] Business Acquisition, Acquiree [Domain] RPM Direct LLC and RPM Data Solutions LLC RPM Direct LLC and RPM Data Solutions LLC [Member] RPM Direct LLC and RPM Data Solutions LLC [Member] Goodwill [Line Items] Goodwill [Line Items] Goodwill [Roll Forward] Goodwill [Roll Forward] Beginning Balance Goodwill arising from acquisition Goodwill, Acquired During Period Currency translation adjustments Goodwill, Translation Adjustments Ending Balance Statement of Comprehensive Income [Abstract] Net income Net Income (Loss) Attributable to Parent Other comprehensive income/(loss): Other Comprehensive Income (Loss), Net of Tax [Abstract] Unrealized gain on effective cash flow hedges, net of taxes $403 and $453, 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 $5 and $6, 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)/loss on cash flow hedges, net of taxes ($25) and $126, respectively Other Comprehensive Income (Loss), Reclassification Adjustment from AOCI on Derivatives, Net of Tax Retirement benefits, net of taxes $1 and $3, respectively 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 Other Comprehensive Income (Loss), Net of Tax Total comprehensive income Comprehensive Income (Loss), Net of Tax, Attributable to Parent Income Statement [Abstract] Cost of revenues (exclusive of depreciation and amortization) Cost of Services, Excluding Depreciation, Depletion, and Amortization Gross profit Gross Profit 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 Operating Expenses Income from operations Operating Income (Loss) Other income/(expense) : Nonoperating Income (Expense) [Abstract] Foreign exchange gain Foreign Currency Transaction Gain (Loss), before Tax Other income, net Other Nonoperating Income (Expense) Income before income taxes Income (Loss) from Continuing Operations before Income Taxes, Extraordinary Items, Noncontrolling Interest Income tax expense Income Tax Expense (Benefit) Net income Earnings per share: Basic (in dollars per share) Earnings Per Share, Basic Diluted (in dollars per share) Earnings Per Share, Diluted Weighted-average number of shares used in computing earnings per share: Weighted Average Number of Shares Outstanding, Diluted [Abstract] Basic weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Basic Diluted weighted average common shares outstanding (in shares) Weighted Average Number of Shares Outstanding, Diluted Equity [Abstract] Capital Structure Stockholders' Equity Note Disclosure [Text Block] Document And Entity Information [Abstract] Document and entity information. Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol 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 Entity Common Stock, Shares Outstanding Entity Common Stock, Shares Outstanding Preferred stock, par value (in dollars per share) Preferred Stock, Par or Stated Value Per Share Preferred stock, shares authorized (in shares) Preferred Stock, Shares Authorized Preferred stock, shares issued (in shares) Preferred Stock, Shares Issued Common stock, par value (in dollars per share) Common Stock, Par or Stated Value Per Share Common stock, shares authorized (in shares) Common Stock, Shares Authorized Common stock, shares issued (in shares) Common Stock, Shares, Issued Common stock, shares outstanding (in shares) Common Stock, Shares, Outstanding Treasury stock (in shares) Treasury Stock, Shares Schedule of Other Current Assets Schedule of Other Current Assets [Table Text Block] Summary of Accrued Expenses and Other Current Liabilities Schedule of Accrued Liabilities [Table Text Block] Summary of Non-current Liabilities Other Noncurrent Liabilities [Table Text Block] Schedule of Accumulated Other Comprehensive Income (Loss) Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block] Summary of Other Income, net Interest and Other Income [Table 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] Restricted Stock Restricted Stock [Member] Restricted stock units vested (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Non-Option Equity Instruments, Outstanding, Number 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, 2016 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, Decrease Resulting from Foreign Currency Translation Balance as of March 31, 2016 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] Employee Benefit Plans Pension and Other Postretirement Benefits Disclosure [Text Block] Schedule of Earnings Per Share, Basic and Diluted Schedule of Earnings Per Share, Basic and Diluted [Table Text Block] Employee Stock Option Employee Stock Option [Member] Employee service share-based compensation, nonvested awards, compensation not yet recognized, stock options Employee Service Share-based Compensation, Nonvested Awards, Compensation Not yet Recognized, Stock Options 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 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] Revolving credit facility Long-term Line of Credit Debt instrument, term (in years) Debt Instrument, Term Option to increase additional credit facility Line Of Credit Facility Option For Additional Borrowing Capacity Line of credit facility option for additional borrowing capacity. Credit facility expiration date Line of Credit Facility, Expiration Date Other short-term borrowings Line of credit interest rate during period (as a percent) Line of Credit Facility, Interest Rate During Period Unamortized debt issuance costs Unamortized Deferred Finance Costs Unamortized Deferred Finance Costs 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 Actuarial loss Defined Benefit Plan Actuarial Gain Loss Included In Net Gratuity Cost Defined benefit plan actuarial gain loss included in net gratuity cost. Net gratuity cost Defined Benefit Plan, Net Periodic Benefit Cost 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. 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. 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 Fixed Assets Property, Plant and Equipment Disclosure [Text Block] Property, Plant and Equipment [Table] Property, Plant and Equipment [Table] 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, computers and software Technology Equipment [Member] Leasehold improvements Leasehold Improvements [Member] Office furniture and equipment Furniture and Fixtures [Member] Capital work in progress Construction in Progress [Member] Buildings Building [Member] Land Land [Member] Motor vehicles Vehicles [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 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 Fixed assets, net Borrowings Debt Disclosure [Text Block] Payables and Accruals [Abstract] Derivative instruments Derivative Instruments and Hedges, Liabilities, Noncurrent Unrecognized tax benefits Unrecognized Tax Benefits that Would Impact Effective Tax Rate Deferred rent Deferred Rent Credit, Noncurrent Retirement benefits Pension and Other Postretirement Defined Benefit Plans, Liabilities, Noncurrent Other non-current liabilities Other Liabilities, Noncurrent Non-current liabilities Schedule of Fixed Assets Property, Plant and Equipment [Table Text Block] Income Taxes Income Tax Disclosure [Text Block] Schedule of Finite-Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Finite-Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Gross Carrying Amount Intangible Assets, Gross (Excluding Goodwill) Accumulated Amortization Finite-Lived Intangible Assets, Accumulated Amortization Net Carrying Amount 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] 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 Other Nonoperating Income (Expense) [Abstract] Other Nonoperating Income (Expense) [Abstract] Interest and dividend income Investment Income, Interest and Dividend Interest expense Interest Expense Change in fair value of earn-out consideration Change In Fair Value Of Earn-Out Consideration Change In Fair Value Of Earn-Out Consideration Other, net Other Miscellaneous Nonoperating Income (Expense) Other Miscellaneous Nonoperating Income (Expense) Other income, net Unrealized gain on investments Unrealized Gain (Loss) on Investments Fair value of earn-out consideration Fair Value Of Earn Out Consideration Fair Value Of Earn Out Consideration Prepaid Expense and Other Assets, Current [Abstract] Prepaid Expense and Other Assets, Current [Abstract] 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 Assets, Current 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] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization and Basis of Presentation Organization, Consolidation and Presentation of Financial Statements Disclosure [Text Block] 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 (in years) Employee Service Share-based Compensation, Nonvested Awards, Compensation Cost Not yet Recognized, Period for Recognition Unrealized gain/(loss) 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 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 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 Cash Flows [Abstract] Cash flows from operating activities: Net Cash Provided by (Used in) Operating Activities, Continuing Operations [Abstract] 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 Change in fair value of earn-out consideration Unrealized foreign exchange (gain)/loss Foreign Currency Transaction Gain (Loss), Unrealized Deferred income taxes Deferred Income Tax Expense (Benefit) Others, net Other Noncash Income (Expense) Change in operating assets and liabilities (net of effect of acquisitions): 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 (used for) / provided by operating activities Net Cash Provided by (Used in) Operating Activities, Continuing Operations Cash flows from investing activities: Net Cash Provided by (Used in) Investing Activities, Continuing Operations [Abstract] Purchase of fixed assets Payments to Acquire Property, Plant, and Equipment Business acquisition (net of cash acquired) Payments to Acquire Businesses, Net of Cash Acquired Purchase of short-term investments Payments to Acquire Short-term Investments Proceeds from redemption of short-term investments Proceeds from Sale of Short-term Investments Net cash used for investing activities Net Cash Provided by (Used in) Investing Activities, Continuing Operations 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 Proceeds from borrowings Proceeds from Issuance of Long-term Debt Repayments of borrowings Repayments of Debt Payment of debt issuance costs Payments of Debt Issuance Costs 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)/provided by financing activities Net Cash Provided by (Used in) Financing Activities, Continuing Operations 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 year Cash and cash equivalents, end of year 2017 Capital Leases, Future Minimum Payments, Next Rolling Twelve Months 2018 Capital Leases, Future Minimum Payments, Due in Rolling Year Two 2019 Capital Leases, Future Minimum Payments, Due in Rolling Year Three 2020 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 Long term capital lease obligation Revenues Based on Geographical Information Revenue from External Customers by Geographic Areas [Table Text Block] Fixed Assets, Net Based on Geographical Information Long-lived Assets by Geographic Areas [Table Text Block] Revenue from External Customers by Products and Services [Table] Revenue from External Customers by Products and Services [Table] Segments [Axis] Segments [Axis] Segments [Domain] Segments [Domain] Revenues and cost of revenues for Company's outsourcing services and transformation services segments [Line Items] Revenue from External Customer [Line Items] Revenues, net Operating expenses Foreign exchange gain and other income, net Nonoperating Income (Expense) Segment Information Segment Reporting Disclosure [Text Block] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] Fair Values Derivatives, Balance Sheet Location, by Derivative Contract Type [Table] 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. Other non current liabilities Other 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 Fair Value Measurements Fair Value, Measurement Inputs, Disclosure [Text Block] Effective tax rates (as a percent) Effective Income Tax Rate Reconciliation, Percent Reversal of unrecognized tax benefit Unrecognized tax benefits Recognized interest and penalties Income Tax Examination, Penalties and Interest Expense Accrued interest on unrecognized tax benefits Unrecognized Tax Benefits, Interest on Income Taxes Accrued Numerators: Net Income (Loss) Attributable to Parent [Abstract] Denominators: 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 (in shares) Earnings Per Share: Earnings Per Share, Basic and Diluted [Abstract] Weighted average common shares considered anti-dilutive in computing diluted earnings per share (in shares) Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount 2017 Operating Leases, Future Minimum Payments, Next Rolling Twelve Months 2018 Operating Leases, Future Minimum Payments, Due in Rolling Year Two 2019 Operating Leases, Future Minimum Payments, Due in Rolling Year Three 2020 Operating Leases, Future Minimum Payments, Due in Rolling Year Four 2021 Operating Leases, Future Minimum Payments, Due in Rolling Year Five 2022 and thereafter Operating Leases, Future Minimum Payments, Due in Rolling after Year Five Total operating lease payments Operating Leases, Future Minimum Payments Due Accrued expenses Accrued Expenses Current Accrued expenses. Derivative instruments Derivative Instruments and Hedges, Liabilities Client liability account Payables to Customers Other current liabilities Other Liabilities, Current Accrued expenses and other current liabilities Restricted Stock and Restricted Stock Units Restricted Stock and Restricted Stock Units [Member] Restricted Stock and Restricted Stock Units [Member] 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. 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 Revenues and Cost of Revenues for Company's Operations Management and Analytics and Business Transformation Segments Schedule of Segment Reporting Information, by Segment [Table 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, 2016 Defined Benefit Plan, Fair Value of Plan Assets Actual return Defined Benefit Plan, Actual Return on Plan Assets 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 March 31, 2016 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] 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 Investments carried at fair value Investments, Fair Value Disclosure 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, 2015 (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Outstanding, Number Number of Options, Granted (in shares) Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross 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 March 31, 2016 (in shares) Number of Options, Vested and exercisable at March 31, 2016 (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, 2015 (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 March 31, 2016 (in dollars per share) Weighted Average Exercise Price, Vested and exercisable at March 31, 2016 (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 March 31, 2016 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 March 31, 2016 (in years) Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested and Expected to Vest, Outstanding, Weighted Average Remaining Contractual Term Goodwill and Intangible Assets Business Combination 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]