Net Income (Loss) Per Share - Additional Information (Detail) - shares		1 Months Ended	3 Months Ended		9 Months Ended
	Jun. 13, 2012	Feb. 28, 2015	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of non-vested early option exercised		188,875	1,757,725	2,047,737	0	2,263,820
Issuance of common stock upon vesting of early exercised options, Shares	573,941				769,070
Stock Options and Restricted Stock Units [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Effect of anti-dilutive securities in computation of pro forma diluted loss per share					1,845,929