Net Income (Loss) Per Share Attributable to Common Stockholders - Summary of Potentially Dilutive Securities (Detail)	6 Months Ended		12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2013	Dec. 31, 2012	Jun. 30, 2011
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	123,883,272	91,593,860	44,710,526	38,244,341	91,421,757
Common stock options [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	39,601,640	7,890,844	23,399,374	36,115,460	7,635,190
Convertible Preferred Stock [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	83,703,016	83,703,016	0	0	83,703,016
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	0	0	5,427,509	1,457,870	0
Common stock subject to repurchase [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	578,616	0	91,504	235,066	83,551
Convertible Notes Payable [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	0	0	7,783,023	0	0
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Total potentially dilutive securities	0	0	7,783,023	0	0