Stock Repurchase Program - Additional Information (Detail) - USD ($)	3 Months Ended
	Mar. 31, 2017	Mar. 31, 2016	Dec. 31, 2008	Dec. 31, 2007
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program			$ 23,100,000	$ 5,000,000
Stock repurchase program expiration date	Sep. 23, 2016
Repurchase of common stock	0	0
Prior Stock Repurchase Program [Member]
Equity, Class of Treasury Stock [Line Items]
Stock repurchase program expiration date	Sep. 22, 2017