Condensed Consolidated Statements of Comprehensive Income (Loss) (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Statement of Comprehensive Income [Abstract]
Net income	$ 37,444	$ 34,407	$ 70,791	$ 66,767
Other comprehensive income (loss), net of tax
Change in defined benefit pension plan, net of tax benefit (expense) of $34, ($2), ($82), and ($16)	(69)	4	162	45
Foreign currency translation adjustment	16,422	(660)	(27,248)	556
Change in fair value of derivative instruments, net of tax benefit (expense) of $223, ($104), ($33), and $213	(433)	202	63	(330)
Other comprehensive income (loss), net of tax	15,920	(454)	(27,023)	271
Comprehensive income	$ 53,364	$ 33,953	$ 43,768	$ 67,038