Stock-Based Compensation - Components of Stock-Based Compensation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Total stock-based compensation expense	$ 1,991	$ 1,809	$ 2,322
Tax benefit of stock-based compensation expense	0	(696)	(892)
After-tax effect of stock based compensation	1,991	1,113	1,430
Stock options
Total stock-based compensation expense	90	194	236
Restricted stock units
Total stock-based compensation expense	$ 1,901	$ 1,615	$ 2,086