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)	22,277					(212)	22,065
Cash dividends	(11,149)						(11,149)
Issuance of treasury shares pursuant to employee stock compensation plans				3,000	1,061		4,061
Tax benefit from employee stock compensation plans					89		89
Vesting of common stock in connection with employee stock compensation plans					1,618		1,618
Other comprehensive income (loss)		(15,816)				(64)	(15,880)
Balance at Jun. 30, 2010	286,328	16,358	320	(11,377)	87,598	1,349	380,576
Balance at Dec. 31, 2010	283,189	28,936	320	(8,945)	95,074	1,862	400,436	[1]
Net income (loss)	25,990					4	25,994
Cash dividends	(11,351)						(11,351)
Issuance of treasury shares pursuant to employee stock compensation plans				4,565	1,921		6,486
Tax benefit from employee stock compensation plans					600		600
Vesting of common stock in connection with employee stock compensation plans					2,361		2,361
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)		(3,148)				1	(3,147)
Balance at Jun. 30, 2011	$ 297,828	$ 24,398	$ 320	$ (4,380)	$ 91,364	$ 4,860	$ 414,390

[1] Condensed from audited financial statements.