Consolidated Statement of Stockholders' Equity (USD $) In Thousands, except Share data, unless otherwise specified	Total	Common stock	Additional paid-in capital	Accumulated deficit	Treasury Stock	Accumulated other comprehensive loss
Balance at Dec. 31, 2012	$ 199,888	$ 494	$ 525,354	$ (322,115)	$ (3,337)	$ (508)
Balance (in shares) at Dec. 31, 2012		49,419,104			136,405
Increase (Decrease) in Stockholders' Equity
Equity component of Senior Convertible Notes	64,361	0	64,361	0	0	0
Deferred tax benefit related to issuance of Senior Convertible Notes	1,295		1,295
Convertible Note Hedge	(70,000)	0	(70,000)	0	0	0
Sale of warrants	41,475	0	41,475	0	0	0
Issuance of warrants in business acquisition	12,000	0	12,000	0	0	0
Exercise of common stock options	65	0	65	0	0	0
Exercise of common stock options (in shares)		4,600
Issuance of restricted stock	0	0	0
Issuance of restricted stock (in shares)		10,000
Cancellation of restricted stock	0	0	0
Cancellation of restricted stock (in shares)		(250)
Stock-based compensation	8,819	0	8,819	0	0	0
Stock-based compensation (in shares)		28,190			0
Proceeds from Board of Directors stock purchases	32	0	32	0	0	0
Proceeds from Board of Directors stock purchases (in shares)		1,874			0
Treasury stock acquisition	(139)	0	0	0	(139)	0
Treasury stock acquisition (in shares)		0			7,840
Comprehensive income	89					89
Net income	48,928	0	0	48,928	0	0
Balance at Jun. 30, 2013	$ 306,814	$ 495	$ 583,401	$ (273,187)	$ (3,476)	$ (419)
Balance (in shares) at Jun. 30, 2013		49,463,518			144,245