Lease Obligations - Additional Information (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Disclosure Lease Obligations Additional Information [Abstract]
Rent expense related to operating leases	$ 1,700	$ 1,800	$ 1,600
Operating Leases, Future Minimum Payments Due, Next Twelve Months	1,300
Operating Leases, Future Minimum Payments, Due in Two Years	649
Operating Leases, Future Minimum Payments, Due in Three Years	484
Operating Leases, Future Minimum Payments, Due in Four Years	424
Operating Leases, Future Minimum Payments, Due in Five Years	273
Future minimum payments under current lease agreements, thereafter	2,200
Future minimum payments under current lease agreements, total	5,300
Payments to Acquire Capital Leases	1,500	$ 1,100
Capital Leases, Future Minimum Payments Due, Next Twelve Months	1,500
Capital Leases, Future Minimum Payments Due in Five Years	625
Capital Leases, Future Minimum Payments Due	$ 5,100