Condensed Consolidated Statement of Equity (unaudited) (USD $) In Thousands	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]	Total
Balance at Dec. 31, 2011	$ 4,542	$ 132,744	$ 841	$ (2,487)	$ 392,937	$ 606	$ 529,183
Balance (in shares) at Dec. 31, 2011	22,711
Net income					29,463	124	29,587
Foreign currency translation adjustments, net of tax			498			(92)	406
Change in unrecognized pension and post-retirement benefit costs, net of tax			(70)				(70)
Change in ownership percentage of subsidiaries						995	995
Stock-based compensation	1	730					731
Stock-based compensation (in shares)	5
Stock issued under incentive plans	14	648					662
Stock issued under incentive plans (in shares)	71
Withholding tax paid upon vesting of RSUs		(716)					(716)
SERP transactions, net		(5)		(193)			(198)
Balance at Sep. 30, 2012	$ 4,557	$ 133,401	$ 1,269	$ (2,680)	$ 422,400	$ 1,633	$ 560,580
Balance (in shares) at Sep. 30, 2012	22,787