Condensed Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended				9 Months Ended
	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 33,846		$ 38,194		$ 124,622		$ 121,383
Other comprehensive (loss) income, net of tax:
Foreign currency translation adjustments	(12,588)		4,109		(11,990)		(900)
Interest rate hedge – gain	619		261		1,600		1,636
Pension – actuarial gain	15		6		44		30
Other comprehensive (loss) income	(11,954)	[1]	4,376	[1]	(10,346)	[1]	766	[1]
Comprehensive income	$ 21,892		$ 42,570		$ 114,276		$ 122,149

[1] Amounts in parentheses represent debits (deferred losses).