Preferred Stock Warrant Liability	12 Months Ended
Dec. 31, 2013
Equity [Abstract]
Preferred Stock Warrant Liability	9. PREFERRED STOCK WARRANT LIABILITY The Company’s Series A redeemable preferred stock warrants were exercised in June 2011. The Company’s Series B redeemable preferred stock warrants converted on a one for one basis to common stock upon the closing of the Company’s initial public offering in June 2011. Upon the closing of the Company’s initial public offering on June 2, 2011, the Series A and Series B redeemable preferred stock warrants that were previously recorded as liabilities on the Company’s consolidated balance sheet were automatically converted to common stock warrants or common stock. Upon this conversion, the related preferred stock warrant liability of $6.6 million was reclassified to additional paid-in capital. The preferred stock warrants were marked to fair value from January 1, 2009 through May 27, 2011, and the change in fair value was recognized in the Company’s consolidated statements of operations as gain or loss from change in fair value of warrant liability. The fair value of the preferred stock warrant liability increased by $3.6 million in the year ended December 31, 2011. The Company recorded this change in fair value as an adjustment to loss from the change in fair value of warrant liability in the consolidated statements of operations.

9. PREFERRED STOCK WARRANT LIABILITY

The Company’s Series A redeemable preferred stock warrants were exercised in June 2011. The Company’s Series B redeemable preferred stock warrants converted on a one for one basis to common stock upon the closing of the Company’s initial public offering in June 2011.

Upon the closing of the Company’s initial public offering on June 2, 2011, the Series A and Series B redeemable preferred stock warrants that were previously recorded as liabilities on the Company’s consolidated balance sheet were automatically converted to common stock warrants or common stock. Upon this conversion, the related preferred stock warrant liability of $6.6 million was reclassified to additional paid-in capital.

The preferred stock warrants were marked to fair value from January 1, 2009 through May 27, 2011, and the change in fair value was recognized in the Company’s consolidated statements of operations as gain or loss from change in fair value of warrant liability. The fair value of the preferred stock warrant liability increased by $3.6 million in the year ended December 31, 2011. The Company recorded this change in fair value as an adjustment to loss from the change in fair value of warrant liability in the consolidated statements of operations.