CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (unaudited) - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Capital Surplus [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income/(Loss) [Member]	Common Stock in Treasury [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	10,447			10,447
Other comprehensive (loss), net of income tax	(238)				(238)
Equity award vesting	0		(9,056)			$ 9,056
Equity award vesting (in shares)						163
Tax benefit from equity awards	(5,787)		(5,787)
Stock-based compensation	1,896		1,896
Shares tendered for taxes	(467)					$ (467)
Shares tendered for taxes (in shares)						(60)
Ending Balance at Mar. 31, 2015	147,923	$ 371	185,936	974,184	963	$ (1,013,531)
Ending Balance (in shares) at Mar. 31, 2015		37,069				(13,516)
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	12,851			12,851
Other comprehensive (loss), net of income tax	(2,656)				(2,656)
Equity award vesting	0		(7,753)			$ 7,753
Equity award vesting (in shares)						171
Tax benefit from equity awards	(913)		(913)
Stock-based compensation	3,890		3,890
Shares tendered for taxes	(165)					$ (165)
Shares tendered for taxes (in shares)						(52)
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	4,107			4,107
Other comprehensive (loss), net of income tax	(239)				(239)
Equity award vesting	0		(111)			$ 111
Equity award vesting (in shares)						37
Tax benefit from equity awards	(4,142)		(4,142)
Stock-based compensation	1,227		1,227
Shares tendered for taxes	(33)					$ (33)
Shares tendered for taxes (in shares)						(12)
Ending Balance at Mar. 31, 2016	$ 162,056	$ 371	$ 178,134	$ 991,330	$ (1,932)	$ (1,005,847)
Ending Balance (in shares) at Mar. 31, 2016		37,069				(13,370)