Consolidated Statements Of Comprehensive Income - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 455,361	$ 454,029	$ 377,292
Other comprehensive income (loss), net of tax:
Foreign currency translation adjustments, net of tax benefit of $643, $65 and $1,841	(38,571)	(44,371)	4,913
Unrealized gain (loss) on derivative instruments, net of tax benefit (expense) of ($1,975), $970 and ($950)	3,320	(1,631)	1,610
Comprehensive income	$ 420,110	$ 408,027	$ 383,815