Consolidated Statements of Changes in Equity - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2012	$ 328,164	$ 118,737	$ 341,586	$ 1,165,952	$ (1,248,377)	$ (49,734)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	512	450	469		(407)
Net tax effect of stock options exercised and release of unvested shares	(2,606)		(2,606)
Stock-based compensation expense	5,744
Stock-based compensation	5,744
Dividends paid ($0.425, $0.255, and $0.34 per share in 2013, 2014, and 2015 respectively)	(16,121)			(16,121)
Treasury stock issued	37		(98)		135
Purchase of treasury stock	(1,662)				(1,662)
Net income (loss)	13,370			13,370
Other comprehensive income	21,616					21,616
Balance at Dec. 31, 2013	349,054	119,187	345,095	1,163,201	(1,250,311)	(28,118)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	(481)	420	(151)		(750)
Net tax effect of stock options exercised and release of unvested shares	(1,993)		(1,993)
Stock-based compensation expense	4,055
Stock-based compensation	4,055
Dividends paid ($0.425, $0.255, and $0.34 per share in 2013, 2014, and 2015 respectively)	(21,485)			(21,485)
Treasury stock issued	540		(767)		1,307
Purchase of treasury stock	(7,894)				(7,894)
Net income (loss)	23,991			23,991
Other comprehensive income	(19,111)					(19,111)
Balance at Dec. 31, 2014	326,676	119,607	346,239	1,165,707	(1,257,648)	(47,229)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of unvested shares	(909)	540	(329)		(1,120)
Net tax effect of stock options exercised and release of unvested shares	1,742		1,742
Stock-based compensation expense	5,733
Stock-based compensation	5,733
Dividends paid ($0.425, $0.255, and $0.34 per share in 2013, 2014, and 2015 respectively)	(21,241)			(21,241)
Treasury stock issued	193		(335)		528
Purchase of treasury stock	(4,619)				(4,619)
Net income (loss)	(170,928)			(170,928)
Other comprehensive income	3,669					3,669
Balance at Dec. 31, 2015	$ 140,316	$ 120,147	$ 353,050	$ 973,538	$ (1,262,859)	$ (43,560)