Schedule of Basic and Diluted Net Income (loss) Per Share (Detail) (USD $) In Thousands, except Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
Basic:
Net loss	$ (1,307)	$ (511)	$ (6,159)	$ (8,465)
Accretion to redemption value of redeemable convertible preferred stock	(3,036)	(3,179)	(9,289)	(9,465)
Reduction in redeemable convertible preferred stock distribution entitlement upon extinguishment	313,933		313,933
Amounts allocated to participating redeemable convertible preferred stock	(266,720)		(282,006)
Net loss attributable to stockholders	42,870	(3,690)	16,478	(17,930)
Weighted average number of common stock shares outstanding	101,358	5,792	38,027	5,787
Net income (loss) per share-basic:	$ 422.95	$ (637.05)	$ 433.33	$ (3,098.31)
Diluted:
Net loss attributable to stockholders	42,870	(3,690)	16,478	(17,930)
Adjustments from assumed conversion of redeemable convertible preferred Stock	(44,177)		(22,637)
Net loss allocated to common stock-diluted	$ (1,307)	$ (3,690)	$ (6,159)	$ (17,930)
Total common stock shares equivalents	731,970	5,792	688,825	5,787
Net loss per share-diluted:	$ (1.79)	$ (637.50)	$ (8.94)	$ (3,098.31)
Common Stock
Diluted:
Total common stock shares equivalents	101,358	5,792	38,027	5,787
Preferred Stock
Diluted:
Total common stock shares equivalents	630,612		650,798
Scenario, Previously Reported
Basic:
Net income (loss) per share-basic:			$ 433.33
Diluted:
Net loss per share-diluted:		$ (637.05)