Consolidated Statements Of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified		Total	Common Stock [Member]	Treasury Stock [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Loss [Member]
BALANCE at Dec. 31, 2013		$ 518,689	$ 482,481	$ (476,796)	$ 513,771	$ (767)
BALANCE (in shares) at Dec. 31, 2013		26,150,900	26,150,900
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, net (in shares)		84,000	83,877
Proceeds from exercise of stock options, net		2,790	2,790
Adjustments related to tax withholding for share-based compensation (in shares)			(53,957)
Adjustments related to tax withholding for share-based compensation		(3,815)	(3,815)
Share-based payments expense (in shares)			240,894
Share-based payments expense		6,844	6,844
Excess tax benefit on share-based compensation expense		825	825
Repurchases of common stock (in shares)			(6,739,257)
Repurchases of common stock		(474,569)		(474,569)
Conversion of debt, issuance of common stock (shares)			182,816
Conversion of callable convertible debt, net of tax		(716)	(10,914)	10,198
Adjustment of debt conversion feature classified as temporary equity		1,283	1,283
Net income		44,928
Foreign currency translation adjustment	[1],[2]	539
BALANCE at Jun. 30, 2014		96,798	479,494	(941,167)	558,699	(228)
BALANCE (in shares) at Jun. 30, 2014		19,865,273
BALANCE at Mar. 31, 2014		121,230	485,537	(901,361)	536,946	108
BALANCE (in shares) at Mar. 31, 2014			20,390,589
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, net (in shares)			26,924
Proceeds from exercise of stock options, net		809	809
Adjustments related to tax withholding for share-based compensation (in shares)			(3,982)
Adjustments related to tax withholding for share-based compensation		(267)	(267)
Share-based payments expense (in shares)			(19,479)
Share-based payments expense		3,079	3,079
Excess tax benefit on share-based compensation expense		514	514
Repurchases of common stock (in shares)			(711,556)
Repurchases of common stock		(50,000)		(50,000)
Conversion of debt, issuance of common stock (shares)			182,777
Conversion of callable convertible debt, net of tax		(720)	(10,914)	10,194
Adjustment of debt conversion feature classified as temporary equity		736	736
Net income		21,753
Foreign currency translation adjustment	[3]	(336)
BALANCE at Jun. 30, 2014		$ 96,798	$ 479,494	$ (941,167)	$ 558,699	$ (228)
BALANCE (in shares) at Jun. 30, 2014		19,865,273

[1] Foreign currency translation adjustment had no tax effect for the three and six months ended June 30, 2014 and 2013, respectively.

[2] Foreign currency translation adjustment has no tax effect for the six months ended June 30, 2014.

[3] Foreign currency translation adjustment has no tax effect for the three months ended June 30, 2014.