Summary of Significant Accounting Policies - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Jan. 01, 2017
Options [Member]
Summary Of Accounting Policies [Line Items]
Shares excluded from computations of diluted loss per share	1,160,015	633,309
ASU 2016-09 [Member]
Summary Of Accounting Policies [Line Items]
Cumulative-effect adjustment to retained earnings			$ 3,200