Condensed Consolidated Statements of Comprehensive Income (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 30,366	$ 33,846	$ 109,872	$ 124,622
Other comprehensive (loss), net of tax:
Foreign currency translation adjustments	(7,900)	(12,588)	(21,783)	(11,990)
Interest rate hedges – net change in deferred (loss) gain	(5,810)	619	(6,480)	1,600
Pension – net change in deferred actuarial gain	53	15	159	44
Other comprehensive (loss), net of tax	(13,657)	(11,954)	(28,104)	(10,346)
Comprehensive income	$ 16,709	$ 21,892	$ 81,768	$ 114,276