Consolidated Statements Of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011
Consolidated Statements Of Comprehensive Income [Abstract]
Net income	$ 7,427	$ 12,736	$ 17,778	$ 25,107
Other comprehensive income (loss):
Unrealized foreign currency translation adjustment (net of tax benefit)	420	(4,307)	(10,875)	1,001
Reclassification adjustment of foreign currency translation gain included in income (net of tax)		(2,781)		(2,781)
Foreign currency translation adjustment	420	(7,088)	(10,875)	(1,780)
Derivative financial instruments adjustment (net of tax benefit)	1,523	(330)	1,276	(546)
Amortization of prior service costs and net gains or losses (net of tax)	1,556	905	4,818	2,925
Other comprehensive income (loss)	3,499	(6,513)	(4,781)	599
Comprehensive income	$ 10,926	$ 6,223	$ 12,997	$ 25,706