Summary of Significant Accounting Policies - Reconciliation of Shares Used to Determine Net Income per Share (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016
Earnings Per Share Disclosure [Line Items]
Net income	$ 5,734	$ 2,944
Weighted average number of shares - basic	41,507,941	32,888,659
Weighted average number of shares outstanding - diluted	43,503,889	33,944,876
Warrants
Earnings Per Share Disclosure [Line Items]
Shares underlying	0	175,285
Options
Earnings Per Share Disclosure [Line Items]
Shares underlying	1,995,948	880,932