Consolidated Statements of Changes in Equity (USD $) In Thousands, unless otherwise specified	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)	Total
Balance at Dec. 31, 2011	$ 118,487	$ 341,149	$ 1,276,266	$ (1,244,224)	$ (45,323)	$ 446,355
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	250	410		(205)		455
Net tax effect of stock options exercised and release of unvested shares		(3,082)				(3,082)
Stock-based compensation		3,412				3,412
Dividends paid ($0.34, $0.255, and $0.425 per share in 2014, 2013, and 2012 respectively)			(26,961)			(26,961)
Treasury stock issued		(303)		454		151
Purchase of treasury stock				(4,402)		(4,402)
Net income (loss)			(83,353)			(83,353)
Other comprehensive income (loss)					(4,411)	(4,411)
Balance at Dec. 31, 2012	118,737	341,586	1,165,952	(1,248,377)	(49,734)	328,164
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	450	469		(407)		512
Net tax effect of stock options exercised and release of unvested shares		(2,606)				(2,606)
Stock-based compensation		5,744				5,744
Dividends paid ($0.34, $0.255, and $0.425 per share in 2014, 2013, and 2012 respectively)			(16,121)			(16,121)
Treasury stock issued		(98)		135		37
Purchase of treasury stock				(1,662)		(1,662)
Net income (loss)			13,370			13,370
Other comprehensive income (loss)					21,616	21,616
Balance at Dec. 31, 2013	119,187	345,095	1,163,201	(1,250,311)	(28,118)	349,054
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	420	(151)		(750)		(481)
Net tax effect of stock options exercised and release of unvested shares		(1,993)				(1,993)
Stock-based compensation		4,055				4,055
Dividends paid ($0.34, $0.255, and $0.425 per share in 2014, 2013, and 2012 respectively)			(21,485)			(21,485)
Treasury stock issued		(767)		1,307		540
Purchase of treasury stock				(7,894)		(7,894)
Net income (loss)			23,991			23,991
Other comprehensive income (loss)					(19,111)	(19,111)
Balance at Dec. 31, 2014	$ 119,607	$ 346,239	$ 1,165,707	$ (1,257,648)	$ (47,229)	$ 326,676