Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Statement of Other Comprehensive Income [Abstract]
Net income	$ 80,901	$ 75,464
Other comprehensive income, net of tax:
Foreign currency translation adjustments, net of tax (expense) benefit of ($16) and $52	1,307	(1,639)
Unrealized gain on derivative instruments, net of tax expense of $337 and $659	566	1,107
Comprehensive income	$ 82,774	$ 74,932