CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income(Loss) [Member]	Treasury Stock [Member]
Beginning Balance at Dec. 31, 2014	$ 142,072	$ 371	$ 198,883	$ 963,737	$ 1,201	$ (1,022,120)
Beginning Balance (in shares) at Dec. 31, 2014		37,069				(13,619)
Net income	11,163			11,163
Other comprehensive (loss), net of income tax	(476)				(476)
Equity award vesting	0		(9,290)			$ 9,290
Equity award vesting (in shares)						198
Tax benefit from equity awards	(6,352)		(6,352)
Stock-based compensation	3,260		3,260
Shares tendered for taxes	(505)					$ (505)
Shares tendered for taxes (in shares)						(70)
Ending Balance at Jun. 30, 2015	149,162	$ 371	186,501	974,900	725	$ (1,013,335)
Ending Balance (in shares) at Jun. 30, 2015		37,069				(13,491)
Net income	12,135			12,135
Other comprehensive (loss), net of income tax	(2,418)				(2,418)
Equity award vesting	0		(7,519)			$ 7,519
Equity award vesting (in shares)						136
Tax benefit from equity awards	(348)		(348)
Stock-based compensation	2,526		2,526
Shares tendered for taxes	(127)					$ (127)
Shares tendered for taxes (in shares)						(42)
Issuance of shares for Directors' compensation	206			188		$ 18
Issuance of shares for Director's compensation (in shares)						2
Ending Balance at Dec. 31, 2015	161,136	$ 371	181,160	987,223	(1,693)	$ (1,005,925)
Ending Balance (in shares) at Dec. 31, 2015		37,069				(13,395)
Net income	8,417			8,417
Other comprehensive (loss), net of income tax	(479)				(479)
Equity award vesting	0		(8,287)	(14,074)		$ 22,361
Equity award vesting (in shares)						402
Tax benefit from equity awards	(5,784)		(5,784)
Stock-based compensation	1,948		1,948
Shares tendered for taxes	(194)					$ (194)
Shares tendered for taxes (in shares)						(88)
Ending Balance at Jun. 30, 2016	$ 165,044	$ 371	$ 169,037	$ 981,566	$ (2,172)	$ (983,758)
Ending Balance (in shares) at Jun. 30, 2016		37,069				(13,081)