Stock-Based Awards - Additional Information (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Capitalized stock-based compensation	$ 166	$ 224
Restricted Stock [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of restricted awards	3 years
Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of share of common stock for each restricted stock unit	1
2011 Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of incentive stock options, non-statutory stock options, restricted stock, restricted stock units and other stock-based awards	7 years
Common stock shares reserved for issuance	4,200,000
Minimum percentage of fair market value of per unit purchase price	100.00%
Shares of common stock available for issuance	1,902,718
Performance based vesting [Member] \| Restricted Stock Units [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Revenue run rate of restricted stock	$ 500,000
Performance based vesting [Member] \| Restricted Stock Units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of restricted awards	2 years
Percentage of target shares allowed to vest	25.00%
Performance based vesting [Member] \| Restricted Stock Units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period of restricted awards	4 years
Percentage of target shares allowed to vest	100.00%
Market-based vesting conditions [Member] \| Restricted Stock Units [Member] \| Minimum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares allowed to vest	50.00%
Market-based vesting conditions [Member] \| Restricted Stock Units [Member] \| Maximum [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of target shares allowed to vest	125.00%
2007 Employee Stock Purchase Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock available for issuance	110,591
Employee Stock Purchase Plan offering period	6 months
Percentage of closing market price of common stock equals to per share purchase price for offerings	85.00%
2012 Inducement Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Maximum term of incentive stock options, non-statutory stock options, restricted stock, restricted stock units and other stock-based awards	7 years
Common stock shares reserved for issuance	257,780
Minimum percentage of fair market value of per unit purchase price	100.00%
Shares of common stock available for issuance	8,900

Offering period under employee purchase plan period.

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- Definition

Minimum Percentage Of Fair Market Value Of Per Unit Purchase Price Of Awards Granted

+ References

No definition available.

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- Definition

Number of share of Common stock for each restricted stock unit.

+ References

No definition available.

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- Definition

Percentage of closing market price of common stock equals to per share purchase price for offerings.

+ References

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- Definition

Percentage Of Target Shares Allowed To Vest Restricted Stock Units

+ References

No definition available.

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- Definition

Maximum term of incentive stock options, non-statutory stock options, restricted stock, restricted stock units and other stock-based awards.

+ References

No definition available.

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- Definition

Share Based Compensation Arrangement Targeted Revenue Run Rate

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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 Statement of Financial Accounting Standard (FAS)

-Number 129

-Paragraph 4

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.29)

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- Definition

Represents the compensation cost capitalized during the period arising from equity-based compensation arrangements (for example, shares of stock, units, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 123R

-Paragraph A240

-Subparagraph g(1)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (h)(1)(ii)

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ 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

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- Definition

The difference between the maximum number of shares (or other type of equity) authorized for issuance under the plan (including the effects of amendments and adjustments), and the sum of: 1) the number of shares (or other type of equity) already issued upon exercise of options or other equity-based awards under the plan; and 2) shares (or other type of equity) reserved for issuance on granting of outstanding awards, net of cancellations and forfeitures, if applicable.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 718

-SubTopic 10

-Section 50

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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