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Stock-Based Compensation - Additional Information (Detail) (USD $) | 3 Months Ended | 6 Months Ended |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | ---
Jun. 30, 2013 | Jun. 30, 2013 | Jun. 30, 2012 | Jun. 30, 2013 Employee Stock Purchase Plan | Jun. 06, 2012 Employee Stock Purchase Plan | Jun. 30, 2013 2008 Equity Incentive Plan | Jun. 12, 2013 2008 Equity Incentive Plan | Jun. 06, 2012 2008 Equity Incentive Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items] |  |  |  |  |  |  |  |
Increase in shares of common stock authorized for issuance |  |  |  |  | 500,000 |  | 6,000,000 | 3,000,000
Maximum number of shares of common stock authorized for issuance |  |  |  |  | 1,320,500 |  |  | 19,540,940
Aggregate number of shares of common stock reserved for future issuance | 12,800,000 | 12,800,000 |  |  |  |  |  |
Outstanding options and other stock based awards | 10,600,000 | 10,600,000 |  |  |  |  |  |
Number of shares available for future issuance |  |  |  | 600,000 |  | 8,200,000 |  |
Restricted stock units vesting Description |  | The restricted stock units vest in three annual installments from the date of grant and are generally issuable at the end of the three-year vesting term |  |  |  |  |  |
Performance-based stock options awards | $ 0 |  | $ 0 |  |  |  |  |
Performance-based stock options, outstanding | 50,000 | 50,000 |  |  |  |  |  |

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- Definition Outstanding options and other stock-based awards under equity incentive plans other than the employee stock purchase plan + References No definition available. + Details
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- Definition Aggregate number of common shares reserved for future issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.29) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Description of award terms as to how many shares or portion of an award are no longer contingent on satisfaction of either a service condition, market condition or a performance condition, thereby giving the employee the legal right to convert the award to shares, to sell the shares, and be entitled to the cash proceeds of such sale. For example, vesting may be expressed as being 25 percent of the shares under option on each anniversary of the grant date. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
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