Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Statement of Comprehensive Income [Abstract]
Net income	$ 32,312	$ 155,173	$ 150,367	$ 344,679
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax benefit of $13 and $41 in 2016 and $313 and $526 in 2015	1,528	(5,072)	490	(32,763)
Unrealized gain (loss) on derivative instruments, net of tax benefit (expense) of ($1,570) and $2,748 in 2016 and ($1,982) and ($2,119) in 2015	2,638	3,332	(4,621)	3,563
Comprehensive income	$ 36,478	$ 153,433	$ 146,236	$ 315,479