Consolidated Statement of Changes in Stockholders' Equity (USD $) In Thousands, except Share data	Treasury Stock [Member]	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance at Dec. 31, 2009		$ 40	$ 501,059	$ (21,012)	$ 480,087
Balance, shares at Dec. 31, 2009		40,022,000
Net income (loss)				(8,468)	(8,468)
Stock option and restricted share awards			1,429		1,429
Stock option and restricted share awards, shares		69,000
Other			68		68
Shares, Other		1,000
Balance at Dec. 31, 2010		40	502,556	(29,480)	473,116
Balance, shares at Dec. 31, 2010		40,092,000
Net income (loss)				26,611	26,611
Stock option and restricted share awards	(8)		2,509		2,501
Stock option and restricted share awards, shares	6,000	217,000
Exercise of stock options			119		119
Exercise of stock options, shares		13,000
Purchase of shares into treasury, shares	916,000
Purchase of shares into treasury	11,353				(11,353)
Other			51		51
Shares, Other		4,000
Balance at Dec. 31, 2011	(11,361)	40	505,235	(2,869)	491,045
Balance, shares at Dec. 31, 2011	922,000	40,326,000
Net income (loss)				58,810	58,810
Stock option and restricted share awards	(318)		4,717		4,399
Stock option and restricted share awards, shares	28,000	226,000
Exercise of stock options			441		441
Exercise of stock options, shares		48,000
Purchase of shares into treasury, shares	549,000				1,465,300
Purchase of shares into treasury	8,798				(8,798)
Other			76		76
Shares, Other		2,000
Balance at Dec. 31, 2012	$ (20,477)	$ 40	$ 510,469	$ 55,941	$ 545,973
Balance, shares at Dec. 31, 2012	1,499,000	40,602,000