Net Loss per Share (Details) (USD $) In Thousands, except Per Share data, unless otherwise specified	12 Months Ended
Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Numerator:
Net loss	$ (170,701)	$ (18,542)	$ (115,344)
Denominator:
Weighted-average shares of stock outstanding	104,789	93,410	84,493
Less: unvested RSAs (in shares)	(2,364)	(2,501)	(2,442)
Weighted average shares used to compute basic and diluted net loss per share	102,425	90,909	82,051
Net loss per share:
Basic and diluted net loss per share (in dollars per share)	$ (1.67)	$ (0.20)	$ (1.41)
Securities that could potentially dilute basic EPS in the future
Anti-dilutive securities (in shares)	6,875	12,035	12,132
Equity Incentive Plans and ESPP
Securities that could potentially dilute basic EPS in the future
Anti-dilutive securities (in shares)	4,095	5,367	5,464
Convertible subordinated notes
Securities that could potentially dilute basic EPS in the future
Anti-dilutive securities (in shares)	2,780	6,668	6,668

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- Definition

Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 260

-SubTopic 10

-Section 50

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The amount of net income or loss for the period per each share in instances when basic and diluted earnings per share are the same amount and reported as a single line item on the face of the financial statements. Basic earnings per share is the amount of net income or loss for the period per each share of common stock or unit outstanding during the reporting period. Diluted earnings per share includes the amount of net income or loss for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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No definition available.

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Net income after adjustments for dividends on preferred stock (declared in the period) and/or cumulative preferred stock (accumulated for the period).

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Average number of shares or units issued and outstanding that are used in calculating basic and diluted earnings per share (EPS).

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No definition available.

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This element represents the weighted average total number of shares issued throughout the period including the first (beginning balance outstanding) and last (ending balance outstanding) day of the period before considering any reductions (for instance, shares held in treasury) to arrive at the weighted average number of shares outstanding. Weighted average relates to the portion of time within a reporting period that common shares have been issued and outstanding to the total time in that period. Such concept is used in determining the weighted average number of shares outstanding for purposes of calculating earnings per share (basic).

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Number of shares of restricted stock determined by relating the portion of time within a reporting period that restricted shares have been outstanding to the total time in that period. Restricted shares are subject to sales, contractual, regulatory or other restrictions that prevent or inhibit the holder from freely disposing of them before the restriction ends.

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