Condensed Consolidated Statement of Equity (unaudited) (USD $) In Thousands, except Share data	Total	Common Stock [Member]	Additional Paid-in Capital [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Company Shares held by SERP [Member]	Retained Earnings [Member]	Noncontrolling Interest [Member]
Balance at December 31, 2010 at Dec. 31, 2010	$ 492,806	$ 4,529	$ 128,831	$ 8,046	$ (2,217)	$ 353,019	$ 598
Balance (in shares) at December 31, 2010 at Dec. 31, 2010		22,646,822
Net income	24,263					24,230	33
Other comprehensive income:
Foreign currency translation adjustments, net of tax	(697)			(676)			(21)
Change in unrecognized pension and post retirement costs, net of tax	(48)			(48)
Comprehensive income	23,518						12
Stock-based compensation	1,623	2	1,621
Stock-based compensation (in shares)		9,447
Stock issued under incentive plans	685	6	679
Stock issued under incentive plans (in shares)		27,652
SERP transactions, net	(137)		5		(142)
Balance at June 30, 2011 at Jun. 30, 2011	$ 518,495	$ 4,537	$ 131,136	$ 7,322	$ (2,359)	$ 377,249	$ 610
Balance (in shares) June 30, 2011 at Jun. 30, 2011		22,683,921