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, 2010		$ 40	$ 502,556	$ (29,480)	$ 473,116
Balance, shares at Dec. 31, 2010		40,092,000
Net income				26,611	26,611
Stock option and restricted share awards			2,509		2,509
Stock option and restricted share awards, shares		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)
Restricted Stock used for tax withholding	(8)				(8)
Restricted Stock used for tax withholding, shares	6,000
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				58,810	58,810
Stock option and restricted share awards			4,717		4,717
Stock option and restricted share awards, shares		226,000
Exercise of stock options			441		441
Exercise of stock options, shares		48,000
Purchase of shares into treasury, shares	549,000
Purchase of shares into treasury	(8,798)				(8,798)
Restricted Stock used for tax withholding	(318)				(318)
Restricted Stock used for tax withholding, shares	28,000
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
Net income				85,274	85,274
Stock option and restricted share awards			7,344		7,344
Stock option and restricted share awards, shares	2,000	258,000
Exercise of stock options		1	1,384		1,385
Exercise of stock options, shares		108,000
Purchase of shares into treasury, shares	334,000
Purchase of shares into treasury	(9,640)				(9,640)
Restricted Stock used for tax withholding	(1,040)				(1,040)
Restricted Stock used for tax withholding, shares	38,000
Other			(83)		(83)
Shares, Other		2,000
Balance at Dec. 31, 2013	$ (31,157)	$ 41	$ 519,114	$ 141,215	$ 629,213
Balance, shares at Dec. 31, 2013	1,873,000	40,970,000