Condensed Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2012	Mar. 31, 2011
Condensed Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 52,171	$ 47,951
Other comprehensive income, net of tax
Gains, losses and reclassification adjustments for derivatives, net of tax	1,221	904
Amortization of retirement obligations, net of tax	1,123	785
Cumulative translation adjustment	15,031	24,878
Other comprehensive income	17,375	26,567
Comprehensive income	$ 69,546	$ 74,518