Summary of Significant Accounting Policies (Policies)	9 Months Ended
Sep. 30, 2022
Accounting Policies [Abstract]
Basis of Preparation	Basis of Preparation and Principles of ConsolidationThe unaudited consolidated financial statements have been prepared in conformity with United States generally accepted accounting principles (“U.S. GAAP”) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for annual financial statements and therefore should be read in conjunction with the audited consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021.
Principles of Consolidation	The unaudited consolidated financial statements reflect all adjustments (of a normal and recurring nature) that management considers necessary for a fair presentation of such statements for the interim periods presented. The unaudited consolidated statements of income for the interim periods presented are not necessarily indicative of the results for the full year or for any subsequent period. The accompanying unaudited consolidated financial statements include the financial statements of ExlService Holdings and all of its subsidiaries. The standalone financial statements of subsidiaries are fully consolidated on a line-by-line basis. Intra-group balances and transactions, and gains and losses arising from intra-group transactions, are eliminated while preparing consolidated financial statements. Accounting policies of the respective individual subsidiary and associate are aligned wherever necessary, so as to ensure consistency with the accounting policies that are adopted by the Company under U.S. GAAP. The Company’s investments in equity affiliates are initially recorded at cost and any excess purchase consideration paid over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee after its acquisition is recognized in the unaudited consolidated statements of income. For purposes of comparability, certain prior period amounts have been reclassified to conform to the current year presentation in accordance with U.S. GAAP.
Use of Estimates	Use of EstimatesThe preparation of the unaudited consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited consolidated financial statements and the unaudited consolidated statements of income during the reporting period. Although these estimates are based on management’s best assessment of the current business environment, actual results may be different from those estimates. The significant estimates and assumptions that affect the unaudited consolidated financial statements include, but are not limited to, estimates of the fair value of the identifiable intangible assets and contingent consideration, purchase price allocation, including revenue projections and discount rate applied within the discounted cash flow model for business acquisitions, allowance for expected credit losses, the nature and timing of the satisfaction of performance obligations, the standalone selling price of performance obligations, and variable consideration in a customer contract, expected recoverability from customers with contingent fee arrangements, estimated costs to complete fixed price contracts, recoverability of dues from statutory authorities, assets and obligations related to employee benefit plans, deferred tax valuation allowances, income-tax uncertainties and other contingencies, valuation of derivative financial instruments, assumptions used to calculate stock-based compensation expense, assumptions used to determine the incremental borrowing rate to calculate lease liabilities and right-of-use (“ROU”) assets, lease term to calculate amortization of ROU, depreciation and amortization periods, and recoverability of long-lived assets, goodwill and intangibles.
Investments	Investments The Company’s short-term investments consist of investments in mutual funds and those term deposits with more than three months of original maturity and less than twelve months of remaining maturity as of the reporting date, while long-term investments consist of term deposits with more than twelve months of remaining maturity as of the reporting date. The Company’s investments in term deposits with financial institutions are measured and recognized at amortized cost. Interest earned on such investments is included in other income, net. The Company’s mutual fund investments are in debt funds in India. These investments are accounted for in accordance with the fair value option under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments. The fair value is represented by original cost on the acquisition date and the net asset value (“NAV”) as quoted, at each reporting period and any changes in fair value are included in other income, net. Gain or loss on the disposal of these investments is calculated using the weighted average cost of the investments sold and is included in other income, net.
Derivative Financial Instruments	Derivative Financial Instruments In the normal course of business, the Company uses derivative instruments to mitigate the exposure from risk of foreign currency and interest rate fluctuations. The Company enters into foreign currency forward contracts to hedge cash flow risks from forecasted transactions denominated in certain foreign currencies, and interest rate swaps to hedge cash flow risks from its revolving credit facility having variable interest rate obligations. These contracts adhere to the Company’s treasury operations’ objectives and policies to qualify as cash flow hedges, and are with counterparties that are highly rated financial institutions. Changes in the fair value of these cash flow hedges are recorded as a component of accumulated other comprehensive income/(loss) (“AOCI”), net of tax. The resultant foreign exchange gain/(loss) upon settlement of cash flow hedges of a forecast transaction are recorded in the unaudited consolidated statements of income along with the underlying hedged item in the same line as part of “Cost of revenues,” “General and administrative expenses,” “Selling and marketing expenses,” and “Depreciation and amortization expense,” as applicable. The accumulated changes in the fair value of interest rate swaps recognized in AOCI are reclassed to the unaudited consolidated statements of income and are presented as a part of “Interest expense” over the term of the contract. The Company evaluates hedge effectiveness of cash flow hedges at the time a contract is entered into as well as on an ongoing basis. For hedge relationships that are discontinued because the forecasted transaction is not expected to occur by the end of the originally specified period, any related derivative amounts recorded in AOCI are reclassified to earnings. The Company also uses derivatives instruments consisting of foreign currency forward contracts to economically hedge intercompany balances and other monetary assets or liabilities denominated in currencies other than the functional currency, against the risk of foreign currency fluctuations associated with remeasurement of such assets and liabilities to functional currency. These derivatives do not qualify as fair value hedges under ASC 815. Changes in the fair value of these derivatives are recognized in the unaudited consolidated statements of income and are included in foreign exchange gain/(loss). The Company also uses foreign currency forward contracts designated as net investment hedges to hedge the foreign currency risks related to the Company's investment in foreign subsidiaries. Gains and losses on these forward contracts are recognized in AOCI as part of the foreign currency translation adjustment. All of the assets and liabilities related to the Company’s forward contracts are subject to master netting arrangements with each individual counterparty. These master netting arrangements generally provide for net settlement of all outstanding contracts with the counterparty in the case of an event of default or a termination event. The Company has presented all of the assets and liabilities related to these contracts on a gross basis, with no offsets, in its consolidated statements of financial position. There is no financial collateral (including cash collateral) provided or received by the Company related to these contracts.
Recent Accounting Pronouncements and Recently adopted Accounting Pronouncements	Recent Accounting Pronouncements In October 2021, FASB issued Accounting Standard Update (“ASU”) No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. This ASU provides guidance in Topic 805 to require the acquirer entity to recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606, Revenue from Contracts with Customers, as if it had originated the contracts. Generally, this should result in an acquirer recognizing and measuring the acquired contract assets and contract liabilities consistent with how they were recognized and measured in the acquiree’s financial statements, if the acquiree prepared financial statements in accordance with U.S. GAAP. The ASU is effective for fiscal years beginning after December 15, 2022. An entity may early adopt the ASU including adoption in an interim period, with retrospective application to all business combinations within the fiscal year that includes such interim period. The Company is currently evaluating the impact of this ASU on its consolidated financial statements. (f)Recently adopted Accounting Pronouncements In March 2020, FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. This ASU provides optional guidance for a limited period of time to ease potential accounting impacts associated with transitioning away from reference rates that are expected to be discontinued, such as interbank offered rates and London Inter-Bank Offered Rate (“LIBOR”). The ASU provides practical expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments are elective and are effective upon issuance for all entities through December 31, 2022. The adoption of this ASU did not have a material impact on the Company’s unaudited consolidated financial statements.

Summary of Significant Accounting Policies (Policies)

9 Months Ended

Sep. 30, 2022

Basis of Preparation and Principles of ConsolidationThe unaudited consolidated financial statements have been prepared in conformity with United States generally accepted accounting principles (“U.S. GAAP”) for interim financial information, the instructions to Form 10-Q and Article 10 of Regulation S-X. Accordingly, they do not include all of the information and footnotes required by U.S. GAAP for annual financial statements and therefore should be read in conjunction with the audited consolidated financial statements and footnotes thereto included in the Company’s Annual Report on Form 10-K for the fiscal year ended December 31, 2021.

Principles of Consolidation

The unaudited consolidated financial statements reflect all adjustments (of a normal and recurring nature) that management considers necessary for a fair presentation of such statements for the interim periods presented. The unaudited consolidated statements of income for the interim periods presented are not necessarily indicative of the results for the full year or for any subsequent period.

The accompanying unaudited consolidated financial statements include the financial statements of ExlService Holdings and all of its subsidiaries. The standalone financial statements of subsidiaries are fully consolidated on a line-by-line basis. Intra-group balances and transactions, and gains and losses arising from intra-group transactions, are eliminated while preparing consolidated financial statements.

Accounting policies of the respective individual subsidiary and associate are aligned wherever necessary, so as to ensure consistency with the accounting policies that are adopted by the Company under U.S. GAAP.

The Company’s investments in equity affiliates are initially recorded at cost and any excess purchase consideration paid over proportionate share of the fair value of the net assets of the investee at the acquisition date is recognized as goodwill. The proportionate share of net income or loss of the investee after its acquisition is recognized in the unaudited consolidated statements of income.

For purposes of comparability, certain prior period amounts have been reclassified to conform to the current year presentation in accordance with U.S. GAAP.

Use of Estimates

Use of EstimatesThe preparation of the unaudited consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the unaudited consolidated financial statements and the unaudited consolidated statements of income during the reporting period. Although these estimates are based on management’s best assessment of the current business environment, actual results may be different from those estimates. The significant estimates and assumptions that affect the unaudited consolidated financial statements include, but are not limited to, estimates of the fair value of the identifiable intangible assets and contingent consideration, purchase price allocation, including revenue projections and discount rate applied within the discounted cash flow model for business acquisitions, allowance for expected credit losses, the nature and timing of the satisfaction of performance obligations, the standalone selling price of performance obligations, and variable consideration in a customer contract, expected recoverability from customers with contingent fee arrangements, estimated costs to complete fixed price contracts, recoverability of dues from statutory authorities, assets and obligations related to employee benefit plans, deferred tax valuation allowances, income-tax uncertainties and other contingencies, valuation of derivative financial instruments, assumptions used to calculate stock-based compensation expense, assumptions used to determine the incremental borrowing rate to calculate lease liabilities and right-of-use (“ROU”) assets, lease term to calculate amortization of ROU, depreciation and amortization periods, and recoverability of long-lived assets, goodwill and intangibles.

Investments

The Company’s short-term investments consist of investments in mutual funds and those term deposits with more than three months of original maturity and less than twelve months of remaining maturity as of the reporting date, while long-term investments consist of term deposits with more than twelve months of remaining maturity as of the reporting date.

The Company’s investments in term deposits with financial institutions are measured and recognized at amortized cost. Interest earned on such investments is included in other income, net.

The Company’s mutual fund investments are in debt funds in India. These investments are accounted for in accordance with the fair value option under Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) Topic 825, Financial Instruments. The fair value is represented by original cost on the acquisition date and the net asset value (“NAV”) as quoted, at each reporting period and any changes in fair value are included in other income, net. Gain or loss on the disposal of these investments is calculated using the weighted average cost of the investments sold and is included in other income, net.

Derivative Financial Instruments

In the normal course of business, the Company uses derivative instruments to mitigate the exposure from risk of foreign currency and interest rate fluctuations. The Company enters into foreign currency forward contracts to hedge cash flow risks from forecasted transactions denominated in certain foreign currencies, and interest rate swaps to hedge cash flow risks from its revolving credit facility having variable interest rate obligations. These contracts adhere to the Company’s treasury operations’ objectives and policies to qualify as cash flow hedges, and are with counterparties that are highly rated financial institutions.

Changes in the fair value of these cash flow hedges are recorded as a component of accumulated other comprehensive income/(loss) (“AOCI”), net of tax. The resultant foreign exchange gain/(loss) upon settlement of cash flow hedges of a forecast transaction are recorded in the unaudited consolidated statements of income along with the underlying hedged item in the same line as part of “Cost of revenues,” “General and administrative expenses,” “Selling and marketing expenses,” and “Depreciation and amortization expense,” as applicable. The accumulated changes in the fair value of interest rate swaps recognized in AOCI are reclassed to the unaudited consolidated statements of income and are presented as a part of “Interest expense” over the term of the contract.

The Company evaluates hedge effectiveness of cash flow hedges at the time a contract is entered into as well as on an ongoing basis. For hedge relationships that are discontinued because the forecasted transaction is not expected to occur by the end of the originally specified period, any related derivative amounts recorded in AOCI are reclassified to earnings.

The Company also uses derivatives instruments consisting of foreign currency forward contracts to economically hedge intercompany balances and other monetary assets or liabilities denominated in currencies other than the functional currency, against the risk of foreign currency fluctuations associated with remeasurement of such assets and liabilities to functional currency. These derivatives do not qualify as fair value hedges under ASC 815. Changes in the fair value of these derivatives are recognized in the unaudited consolidated statements of income and are included in foreign exchange gain/(loss).

The Company also uses foreign currency forward contracts designated as net investment hedges to hedge the foreign currency risks related to the Company's investment in foreign subsidiaries. Gains and losses on these forward contracts are recognized in AOCI as part of the foreign currency translation adjustment. All of the assets and liabilities related to the Company’s forward contracts are subject to master netting arrangements with each individual counterparty. These master netting arrangements generally provide for net settlement of all outstanding contracts with the counterparty in the case of an event of default or a termination event. The Company has presented all of the assets and liabilities related to these contracts on a gross basis, with no offsets, in its consolidated statements of financial position. There is no financial collateral (including cash collateral) provided or received by the Company related to these contracts.

Recent Accounting Pronouncements and Recently adopted Accounting Pronouncements

Recent Accounting Pronouncements

In October 2021, FASB issued Accounting Standard Update (“ASU”) No. 2021-08, Business Combinations (Topic 805): Accounting for Contract Assets and Contract Liabilities from Contracts with Customers. This ASU provides guidance in Topic 805 to require the acquirer entity to recognize and measure contract assets and contract liabilities acquired in a business combination in accordance with Topic 606, Revenue from Contracts with Customers, as if it had originated the contracts. Generally, this should result in an acquirer recognizing and measuring the acquired contract assets and contract liabilities consistent with how they were recognized and measured in the acquiree’s financial statements, if the acquiree prepared financial statements in accordance with U.S. GAAP. The ASU is effective for fiscal years beginning after December 15, 2022. An entity may early adopt the ASU including adoption in an interim period, with retrospective application to all business combinations within the fiscal year that includes such interim period. The Company is currently evaluating the impact of this ASU on its consolidated financial statements.

(f)Recently adopted Accounting Pronouncements

In March 2020, FASB issued ASU No. 2020-04, Reference Rate Reform (Topic 848): Facilitation of the Effects of Reference Rate Reform on Financial Reporting. This ASU provides optional guidance for a limited period of time to ease potential accounting impacts associated with transitioning away from reference rates that are expected to be discontinued, such as interbank offered rates and London Inter-Bank Offered Rate (“LIBOR”). The ASU provides practical expedients and exceptions for applying U.S. GAAP to contracts, hedging relationships, and other transactions affected by reference rate reform if certain criteria are met. The amendments are elective and are effective upon issuance for all entities through December 31, 2022. The adoption of this ASU did not have a material impact on the Company’s unaudited consolidated financial statements.