Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Accrued Liabilities And Other Liabilities [Abstract]
Accrued expenses	$ 163,400	$ 161,672
Accrued employee cost	179,360	158,054
Deferred transition revenue	50,552	44,974
Statutory liabilities	36,878	32,149
Retirement benefits	17,616	17,930
Derivative instruments	4,777	34,610
Advance from customers	21,969	19,815
Earn-out consideration	6,885	16,896
Other liabilities	15,461	12,210
Capital lease obligations	1,349	1,328
Accrued expenses and other current liabilities, net	$ 498,247	$ 499,638