Consolidated Statements of Comprehensive (Loss)/Income (Unaudited) - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Statement of Comprehensive Income [Abstract]
Net income		$ 15,249	$ 21,077	$ 52,869	$ 58,243
Other comprehensive (loss)/income:
Unrealized (loss)/gain on effective cash flow hedges, net of taxes ($3,596), $314, ($7,969) and $3,895, respectively		(8,348)	524	(21,218)	8,216
Foreign currency translation (loss)/gain		(18,373)	(3,030)	(44,403)	10,813
Reclassification adjustments
Loss/(gain) on cash flow hedges, net of taxes $19, ($604), ($1,183) and ($1,497), respectively(1)	[1]	46	(1,375)	(2,890)	(3,397)
Retirement benefits, net of taxes ($4), $30, ($6) and $77, respectively(2)	[2]	(34)	42	(109)	135
Total other comprehensive (loss)/income		(26,709)	(3,839)	(68,620)	15,767
Total comprehensive (loss)/income		$ (11,460)	$ 17,238	$ (15,751)	$ 74,010

[1] These are reclassified to net income and are included either in cost of revenues or operating expenses, as applicable in the unaudited consolidated statements of income. Refer to Note 17 to the unaudited consolidated financial statements.

[2] These are reclassified to net income and are included in other income, net in the unaudited consolidated statements of income. Refer to Note 20 to the unaudited consolidated financial statements.