Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 71,166	$ 100,943	$ 118,055	$ 189,506
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax benefit (expense) of ($172) and $28 in 2016 and $198 and $213 in 2015	(10,904)	2,465	(1,038)	(27,691)
Unrealized gain (loss) on derivative instruments, net of tax benefit (expense) of $44 and $4,318 in 2016 and $798 and ($137) in 2015	(74)	(1,341)	(7,259)	231
Comprehensive income	$ 60,188	$ 102,067	$ 109,758	$ 162,046