Condensed Consolidated Statements Of Changes In Equity (USD $) In Thousands	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Common Stock [Member]	Treasury Stock [Member]	Paid-In Capital [Member]	Noncontrolling Interest [Member]	Total
Balance at Dec. 31, 2009	$ 275,200	$ 32,174	$ 320	$ (14,377)	$ 84,830	$ 1,625	$ 379,772
Net income (loss)	39,694					(322)	39,372
Cash dividends	(16,745)						(16,745)
Issuance of treasury shares pursuant to employee stock compensation plans				3,769	1,330		5,099
Tax benefit from employee stock compensation plans					343		343
Vesting of common stock in connection with employee stock compensation plans					2,462		2,462
Purchase of noncontrolling interest					2,701		2,701
Other comprehensive income (loss)		(2,796)				(49)	(2,845)
Balance at Sep. 30, 2010	298,149	29,378	320	(10,608)	91,666	1,254	410,159
Balance at Dec. 31, 2010	283,189	28,936	320	(8,945)	95,074	1,862	400,436	[1]
Net income (loss)	45,415					48	45,463
Cash dividends	(17,051)						(17,051)
Issuance of treasury shares pursuant to employee stock compensation plans				4,820	2,048		6,868
Tax benefit from employee stock compensation plans					598		598
Vesting of common stock in connection with employee stock compensation plans					3,681		3,681
Purchase of noncontrolling interest					(5,189)	(546)	(5,735)
Sale of subsidiary shares to noncontrolling interest		(1,390)			(3,403)	4,793
Deconsolidation of variable interest entity						(1,254)	(1,254)
Other comprehensive income (loss)		(28,003)				(647)	(28,650)
Balance at Sep. 30, 2011	$ 311,553	$ (457)	$ 320	$ (4,125)	$ 92,809	$ 4,256	$ 404,356

[1] Condensed from audited financial statements.