Employee Benefit Plan - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
General Discussion Of Pension And Other Postretirement Benefits [Abstract]
Profit Sharing and Deferred Compensation Plan	$ 321,000	$ 269,000
Transfers from the profit sharing plan’s forfeiture account	$ 0	$ 26,000