Credit Facilities and Long-Term Debt - Lines of Credit - Additional Information (Detail) - USD ($)		1 Months Ended	3 Months Ended		9 Months Ended
	Apr. 06, 2015	Nov. 26, 2014	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2014
Line of Credit Facility [Line Items]
Sale And Dispositions of Assets, Maximum Limit					$ 2,000,000
NIL Funding [Member] | Loan Agreement And Promissory Note [Member]
Line of Credit Facility [Line Items]
Debt Instrument, Interest Rate, Stated Percentage	7.50%
Debt Instrument, Maturity Date	Oct. 03, 2015
Debt Instrument, Face Amount	$ 5,000,000
Revolving Credit Facility [Member] | Bank of America [Member]
Line of Credit Facility [Line Items]
Line Of Credit Facility Maximum Borrowing Capacity Increased		$ 10,000,000
Line of credit maturity date					Apr. 01, 2017
Outstanding borrowings			$ 15,800,000		$ 15,800,000		$ 28,800,000
Interest expense related to line of credit			$ 110,000	$ 146,000	$ 423,000	$ 421,000
Debt Instruments Weighted Average Interest Rate			2.32%	2.50%	2.39%	2.42%
Line of Credit Facility, Maximum Borrowing Capacity		40,000,000	$ 30,000,000		$ 30,000,000
Short-term Non-bank Loans and Notes Payable		$ 5,000,000
Debt Instrument, Maturity Date		Jul. 01, 2015