Consolidated Statements of Comprehensive Income (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Statement of Comprehensive Income [Abstract]
Net income	$ 19,876	$ 28,872	$ 45,362	$ 54,970
Other comprehensive income (loss), net of tax:
Currency translation adjustments (net of income tax of $0 in 2014 and income tax expense of $56 and benefit of $539 in 2013)	(570)	1,683	(103)	(6,144)
Change in unrecognized net periodic pension costs (net of income tax expense of $90 and $187 in 2014 and $132 and $266 in 2013)	112	209	219	417
Other (net of income tax benefit of $8 and $16 in 2014 and $8 and $16 in 2013)	15	(12)	6	(25)
Total other comprehensive income (loss), net of tax	(443)	1,880	122	(5,752)
Comprehensive income	$ 19,433	$ 30,752	$ 45,484	$ 49,218