Basic and Diluted Net Income (Loss) Per Share - Earnings (Loss) Per Share Calculation (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	3 Months Ended				6 Months Ended
	Jun. 30, 2013		Jun. 30, 2012		Jun. 30, 2013		Jun. 30, 2012
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (4,112)		$ 1,307		$ (10,669)		$ (3,508)
Interest on convertible notes, net of tax benefit	0		0	[1]	0		0	[1]
Net income (loss), diluted	$ (4,112)		$ 1,307		$ (10,669)		$ (3,508)
Weighted average shares used to calculate net income (loss) per share, basic	28,669		26,759		28,570		26,708
Effect of escrow shares	0		1,344		0		0
Effect of convertible notes	0	[1]	0	[1]	0	[1]	0	[1]
Weighted average shares used to calculate net income (loss) per share, diluted	28,669		28,256		28,570		26,708
Basic (in dollars per share)	$ (0.14)		$ 0.05		$ (0.37)		$ (0.13)
Diluted (in dollars per share)	$ (0.14)	[1],[2]	$ 0.05	[1],[2]	$ (0.37)	[1],[2]	$ (0.13)	[1],[2]
Restricted Stock Units (RSUs) [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive equity awards	0	[3],[4]	78	[3],[4]	0	[3],[4]	0	[3],[4]
Stock Options [Member]
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Effect of dilutive equity awards	0	[3]	75	[3]	0	[3]	0	[3]

[1] For the three months ended June 30, 2013 and 2012, 2.1 million and 3.5 million as-if converted shares associated with the Company's convertible senior notes were excluded from the calculation as their effect would have been anti-dilutive. For the six months ended June 30, 2013 and 2012, 2.4 million and 3.5 million as-if converted shares associated with the Company's convertible senior notes were excluded from the calculation as their effect would have been anti-dilutive

[2] (A)For the three months ended June 30, 2013, there were no remaining contingently issuable shares outstanding. For the six months ended June 30, 2013 and 2012, 30,000 and 1.3 million contingently issuable shares were excluded from the calculation as their effect would have been anti-dilutive.

[3] For the three and six months ended June 30, 2013 and 2012, the following equity awards, by type, were excluded from the calculation, as their effect would have been anti-dilutive (in thousands): Three Months Ended Six Months Ended June 30, June 30, 2013 2012 2013 2012Stock options2,375 2,330 2,375 2,400Restricted stock units441 399 438 478Performance based restricted stock units (D)2,087 729 2,087 848Total equity award shares excluded4,903 3,458 4,900 3,726

[4] For the three and six months ended June 30, 2013, the Company excluded 2.0 million restricted stock units granted under the Long-Term Incentive Plan ("LTIP") as the performance criteria required for issuance of the awards was not satisfied as of these dates. For the three and six months ended June 30, 2013, the Company excluded 0.1 million restricted stock units granted under the