Lease Obligations - Additional Information (Detail) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011
Disclosure Lease Obligations Additional Information [Abstract]
Rent expense related to operating leases	$ 1,600,000	$ 1,400,000	$ 1,100,000
Future minimum payments under current lease agreements, year 2014	1,200,000
Future minimum payments under current lease agreements, year 2015	1,100,000
Future minimum payments under current lease agreements, year 2016	851,000
Future minimum payments under current lease agreements, year 2017	446,000
Future minimum payments under current lease agreements, year 2018	419,000
Future minimum payments under current lease agreements, thereafter	2,700,000
Future minimum payments under current lease agreements, total	6,800,000
Payments to Acquire Capital Leases	292,000
Capital Leases, Future Minimum Payments Due, Next Twelve Months	1,100,000
Capital Leases, Future Minimum Payments Due in Two Years	1,500,000
Capital Leases, Future Minimum Payments Due Thereafter	625,000
Capital Leases, Future Minimum Payments Due	$ 7,700,000