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)	88,000		87,789
Proceeds from exercise of stock options, net	2,943		2,943
Adjustments related to tax withholding for share-based compensation (in shares)			(57,694)
Adjustments related to tax withholding for share-based compensation	(4,027)		(4,027)
Share-based payments expense (in shares)			207,398
Share-based payments expense	10,093		10,093
Excess tax benefit on share-based compensation expense	1,992		1,992
Repurchases of common stock (in shares)			(7,925,227)
Repurchases of common stock	(545,156)			(545,156)
Conversion of debt, issuance of common stock (shares)			431,760
Conversion of callable convertible debt, net of tax	(516)		(24,771)	24,255
Adjustment and settlement of debt conversion feature classified as temporary equity	1,446		1,446
Net income	62,818				62,818
Foreign currency translation adjustment	(156)	[1],[2]				(156)	[3]
BALANCE at Sep. 30, 2014	48,126		470,157	(997,697)	576,589	(923)
BALANCE (in shares) at Sep. 30, 2014	18,894,926
BALANCE at Jun. 30, 2014	96,798		479,494	(941,167)	558,699	(228)
BALANCE (in shares) at Jun. 30, 2014			19,865,273
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Proceeds from exercise of stock options, net (in shares)			3,912
Proceeds from exercise of stock options, net	153		153
Adjustments related to tax withholding for share-based compensation (in shares)			(3,737)
Adjustments related to tax withholding for share-based compensation	(212)		(212)
Share-based payments expense (in shares)			(33,496)
Share-based payments expense	3,249		3,249
Excess tax benefit on share-based compensation expense	1,167		1,167
Repurchases of common stock (in shares)			(1,185,970)
Repurchases of common stock	(70,587)			(70,587)
Conversion of debt, issuance of common stock (shares)			248,944
Conversion of callable convertible debt, net of tax	200		(13,857)	14,057
Adjustment and settlement of debt conversion feature classified as temporary equity	163		163
Net income	17,890				17,890
Foreign currency translation adjustment	(695)	[1],[2]				(695)	[4]
BALANCE at Sep. 30, 2014	$ 48,126		$ 470,157	$ (997,697)	$ 576,589	$ (923)
BALANCE (in shares) at Sep. 30, 2014	18,894,926

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

[2] Foreign currency translation adjustment had no tax effect in 2014.

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

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