Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 96,905	$ 80,004	$ 177,806	$ 155,468
Other comprehensive income, net of tax:
Foreign currency translation adjustments, net of tax (expense) benefit of ($123) and ($139) in 2014 and $169 and $221 in 2013	(1,459)	(4,688)	(152)	(6,327)
Unrealized (loss) gain on derivative instruments, net of tax benefit (expense) of $941 and $604 in 2014 and ($1,137) and ($1,796) in 2013	(1,581)	1,913	(1,015)	3,020
Comprehensive income	$ 93,865	$ 77,229	$ 176,639	$ 152,161