Employee Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Compensation And Retirement Disclosure [Abstract]
Defined contribution plan maximum employee contribution of employee salary	3.00%	3.00%
Defined contribution plan maximum annual employer matching contribution per employee			$ 2,000
Employee benefit plans, contribution expense	$ 819,000	$ 525,000	$ 153,000