CONDENSED CONSOLIDATED STATEMENTS OF SHAREHOLDERS' EQUITY (USD $) In Thousands, except Share data	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, 2011	$ 169,105	$ 371	$ 184,207	$ 833,347	$ (9,479)	$ (839,341)
Beginning Balance (in shares) at Dec. 31, 2011		37,069,000				(10,969,000)
Net income	106,586			106,586
Other comprehensive income, net of income tax	332				332
Equity award vesting and exercises	8,091		(4,179)	(4,787)		17,057
Equity award vesting and exercises (in shares)						266,000
Tax benefit from equity awards	930		930
Stock-based compensation	8,309		8,309
Common shares repurchased	(207,918)					(207,918)
Common shares repurchased (in shares)	(3,025,700)					(3,026,000)
Issuance of shares for Directors' compensation	37			(1)		38
Issuance of shares for Directors' compensation (in shares)						1,000
Shares tendered for taxes	(1,442)					(1,442)
Shares tendered for taxes (in shares)						(22,000)
Ending Balance at Jun. 30, 2012	84,030	371	189,267	935,145	(9,147)	(1,031,606)
Ending Balance (in shares) at Jun. 30, 2012		37,069,000				(13,750,000)
Net income	32,384			32,384
Other comprehensive income, net of income tax	1,217				1,217
Equity award vesting and exercises	254		(45)	(56)		355
Equity award vesting and exercises (in shares)						6,000
Tax benefit from equity awards	(12)		(12)
Stock-based compensation	7,903		7,903
Shares tendered for taxes	(11)					(11)
Shares tendered for taxes (in shares)						0
Ending Balance at Dec. 31, 2012	125,765	371	197,113	967,473	(7,930)	(1,031,262)
Ending Balance (in shares) at Dec. 31, 2012		37,069,000				(13,744,000)
Net income	2,932			2,932
Other comprehensive income, net of income tax	143				143
Equity award vesting and exercises	0		(3,189)			3,189
Equity award vesting and exercises (in shares)						66,000
Tax benefit from equity awards	(4,177)		(4,177)
Stock-based compensation	5,394		5,394
Common shares repurchased	0
Common shares repurchased (in shares)	0
Shares tendered for taxes	(371)					(371)
Shares tendered for taxes (in shares)						(22,000)
Ending Balance at Jun. 30, 2013	$ 129,686	$ 371	$ 195,141	$ 970,405	$ (7,787)	$ (1,028,444)
Ending Balance (in shares) at Jun. 30, 2013		37,069,000				(13,700,000)