Condensed Consolidated Statements of Comprehensive Income (Unaudited) (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Condensed Consolidated Statements of Comprehensive Income [Abstract]
Net income	$ 20,099	$ 13,026	$ 52,409	$ 32,953
Foreign currency translation adjustments	9,048	(17,379)	4,473	889
Deferred gains (losses) on cash flow hedges, net of taxes of $196, $(267), $333, and $(273), respectively.	(495)	668	(836)	684
Amortization of unrecognized retirement obligations, net of taxes of $1,769, $1,535, $5,438,and $4,445, respectively.	3,013	2,475	8,961	7,150
Other comprehensive income (loss)	11,566	(14,236)	12,598	8,723
Comprehensive income (loss)	$ 31,665	$ (1,210)	$ 65,007	$ 41,676