Stockholders' Equity - Additional Information (Detail) - USD ($)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014	Oct. 22, 2014	Nov. 01, 2007
Equity [Abstract]
Stock repurchase program, authorized amount					$ 50,000,000
Stock repurchase program, additional authorized amount				$ 30,000,000
Repurchased shares	105,750	0	1,527,647
Repurchased shares, value	$ 729,000		$ 15,000,000
Stock repurchase program, average cost	$ 6.90		$ 9.82
Stock repurchase program, remaining authorized repurchase amount	$ 33,700,000