Segment and Geographical Information - Revenues and Cost of Revenues for Company's Reportable Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	$ 183,033	$ 167,036
Cost of revenues (exclusive of depreciation and amortization)	120,119	108,379
Gross profit	62,914	58,657
Operating expenses	47,012	42,205
Foreign exchange gain, interest expense and other income, net	4,446	3,263
Income tax expense	3,560	5,895
Net income	16,788	13,820
Insurance
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	55,921	48,299
Cost of revenues (exclusive of depreciation and amortization)	38,329	34,269
Gross profit	17,592	14,030
Healthcare
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	18,932	16,388
Cost of revenues (exclusive of depreciation and amortization)	12,186	10,545
Gross profit	6,746	5,843
Travel, Transportation and Logistics
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	17,043	17,559
Cost of revenues (exclusive of depreciation and amortization)	10,224	10,463
Gross profit	6,819	7,096
Finance and Accounting
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	21,014	19,818
Cost of revenues (exclusive of depreciation and amortization)	12,898	11,444
Gross profit	8,116	8,374
All Other
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	21,116	26,006
Cost of revenues (exclusive of depreciation and amortization)	14,444	16,887
Gross profit	6,672	9,119
Analytics
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	49,007	38,966
Cost of revenues (exclusive of depreciation and amortization)	32,038	24,771
Gross profit	16,969	14,195
BPM and Related Services
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	134,026	128,070
Analytics Services
Revenues and cost of revenues for Company's reportable segments [Line Items]
Revenues, net	$ 49,007	$ 38,966