Aggregate Notional Principal Amounts of Outstanding Derivative Financial Instruments with Related Balance Sheet Exposure (Detail) - USD ($)		Dec. 31, 2016	Dec. 31, 2015
Derivative [Line Items]
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	$ 38,034,000	$ (29,240,000)
United States Dollars (sell) Indian Rupees (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	1,108,400,000	1,139,400,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	6,669,000	(48,197,000)
United States Dollars (sell) Mexican Peso (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	9,120,000	8,520,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	(187,000)	(1,163,000)
United States Dollars (sell) Philippines Peso (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	70,050,000	58,500,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	(1,036,000)	(1,387,000)
Euro (sell) United States Dollars (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	138,613,000	146,719,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	9,180,000	9,109,000
Euro (sell) Romanian Leu (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	29,805,000	39,027,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	(152,000)	567,000
Japanese Yen (sell) Chinese Renminbi (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	77,267,000	62,740,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	(742,000)	(1,379,000)
Pound Sterling (sell) United States Dollars (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	104,142,000	118,438,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	14,228,000	7,496,000
Australian Dollars (sell) United States Dollars (buy)
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	114,412,000	106,544,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	2,328,000	$ 5,714,000
Interest Rate Swap Floating To Fixed [Member]
Derivative [Line Items]
Derivative instrument notional principal amount	[2]	456,810,000
Derivative financial instrument, balance sheet exposure asset (liability)	[1]	$ 7,746,000

[1] Balance sheet exposure is denominated in U.S. dollars and denotes the mark-to-market impact of the derivative financial instruments on the reporting date.

[2] Notional amounts are key elements of derivative financial instrument agreements but do not represent the amount exchanged by counterparties and do not measure the Company’s exposure to credit or market risks. However, the amounts exchanged are based on the notional amounts and other provisions of the underlying derivative financial instrument agreements.