Stock Repurchase Plan - Additional Information (Detail) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2016	Nov. 14, 2016
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program, authorized amount			$ 10,000,000
Repurchase of common stock, shares	510,923
Aggregate cost of common stock repurchased	$ 9,990,000	$ 9,990,000
Average purchase price of common stock	$ 19.57