Stockholders' Equity - Summary of Roll Forward of Restricted Stock Activity Pursuant to the 2010 and 2013 Stock Plan (Detail) - 2010 and 2013 Stock Incentive Plans [Member] - Unvested Restricted Stock [Member]	12 Months Ended
	Dec. 31, 2016 shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unvested at December 31, 2015	959,864
Granted	997,956
Vested	(589,409)
Cancelled	(71,357)
Unvested at December 31, 2016	1,297,054