Consolidated Statements of Changes in Equity (USD $) In Thousands, unless otherwise specified	Total	Common Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Income (Loss)
Balance at Dec. 31, 2009	$ 401,643	$ 118,243	$ 333,612	$ 1,217,975	$ (1,236,217)	$ (31,970)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of nonvested shares	(49)	53	22	0	(124)	0
Net tax effect of stock options exercised and release of nonvested shares	(588)	0	(588)	0	0	0
Stock-based compensation	3,907	0	3,907	0	0	0
Dividends paid ($0.43, $0.32, and $0.30 per share at December 31, 2012, December 31, 2011, and December 31, 2010 respectively)	(19,141)	0	0	(19,141)	0	0
Treasury stock issued	159	0	(158)	0	317	0
Net income (loss)	53,604	0	0	53,604	0	0
Other comprehensive loss	(1,712)	0	0	0	0	(1,712)
Balance at Dec. 31, 2010	437,823	118,296	336,795	1,252,438	(1,236,024)	(33,682)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of nonvested shares	520	191	522	0	(193)	0
Net tax effect of stock options exercised and release of nonvested shares	(959)	0	(959)	0	0	0
Stock-based compensation	4,988	0	4,988	0	0	0
Dividends paid ($0.43, $0.32, and $0.30 per share at December 31, 2012, December 31, 2011, and December 31, 2010 respectively)	(20,370)	0	0	(20,370)	0	0
Treasury stock issued	159	0	(197)	0	356	0
Purchase of treasury stock	(8,363)	0	0	0	(8,363)	0
Net income (loss)	44,198	0	0	44,198	0	0
Other comprehensive loss	(11,641)	0	0	0	0	(11,641)
Balance at Dec. 31, 2011	446,355	118,487	341,149	1,276,266	(1,244,224)	(45,323)
Increase (Decrease) in Stockholders' Equity
Exercise of stock options and release of nonvested shares	455	250	410	0	(205)	0
Net tax effect of stock options exercised and release of nonvested shares	(3,082)	0	(3,082)	0	0	0
Stock-based compensation	3,412	0	3,412	0	0	0
Dividends paid ($0.43, $0.32, and $0.30 per share at December 31, 2012, December 31, 2011, and December 31, 2010 respectively)	(26,961)	0	0	(26,961)	0	0
Treasury stock issued	151	0	(303)	0	454	0
Purchase of treasury stock	(4,402)	0	0	0	(4,402)	0
Net income (loss)	(83,353)	0	0	(83,353)	0	0
Other comprehensive loss	(4,411)	0	0	0	0	(4,411)
Balance at Dec. 31, 2012	$ 328,164	$ 118,737	$ 341,586	$ 1,165,952	$ (1,248,377)	$ (49,734)