Benefit Plan - Summary of Pension Benefit Obligation (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Change in benefit obligation
Benefit obligation at beginning of year	$ 6,800
Service cost		$ 70
Interest cost	239	335
Gain on reduction of pension liability		(2,208)
Actuarial (gain) loss	(775)
Benefits paid	(6,264)
Benefit obligation at end of period		6,800
Change in plan assets
Fair value of plan assets at beginning of year	5,479
Actual return on plan assets	14
Employer contributions	771
Benefit paid	$ (6,264)
Fair value of plan assets at end of period		$ 5,479