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
	Mar. 31, 2014		Mar. 31, 2013
Earnings Per Share, Diluted, by Common Class, Including Two Class Method [Line Items]
Net income (loss)	$ (10,434)		$ (6,557)
Interest on convertible notes, net of tax benefit	0		0	[1]
Net income (loss), diluted	$ (10,434)		$ (6,557)
Weighted average shares used to calculate net income (loss) per share, basic	29,864		28,470
Effect of escrow shares	0	[2]	0	[2]
Effect of convertible notes	0	[1]	0	[1]
Weighted average shares used to calculate net income (loss) per share, diluted	29,864		28,470
Basic (in dollars per share)	$ (0.35)		$ (0.23)
Diluted (in dollars per share)	$ (0.35)		$ (0.23)	[1],[2],[3],[4]
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]	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]	0	[3]

[1] For the three months ended March 31, 2014 and 2013, 2.1 million and 2.8 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 March 31, 2014 there were no remaining contingently issuable shares outstanding. For the three months ended March 31, 2013, 0.1 million contingently issuable shares were excluded from the calculation as their effect would have been anti-dilutive.

[3] For the three months ended March 31, 2014 and 2013, the following equity awards, by type, were excluded from the calculation, as their effect would have been anti-dilutive (in thousands): Three Months Ended March 31, 2014 2013Stock options3,188 2,892Restricted stock units282 488Performance based restricted stock units (D)674 985Total equity award shares excluded4,144 4,365

[4] under the Long-Term Incentive Plan ("LTIP") are presented based on attainment of 100% of the performance goals being met. The LTIP provides for the grants of awards payable in shares of common stock upon the achievement of performance goals set by the Company's Compensation and Development Committee. In addition to the performance conditions, the awards contain market-based multipliers based on the average price of the Company's common stock thirty days prior to the end of each semi-annual performance period. The maximum multiplier for a given semi-annual performance period is 2.75x the original grant and overall achievement is limited to a maximum of 2.5x of the target award over the entire performance period. Based on this formula, the maximum number of shares that could be earned was 1.8 million and 2.1 million for the three months ended March 31, 2014 and 2013