Income Taxes - Additional Information (Detail) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2015	Sep. 30, 2014	Sep. 30, 2015	Sep. 30, 2014	Dec. 31, 2013	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Income tax provision	$ 559,000	$ 714,000	$ 303,000	$ 2,721,000
Effective tax rate	35.20%		34.30%
Deferred tax asset valuation allowance	$ 1,500,000		$ 1,500,000		$ 36,200,000	$ 1,500,000
Pre-tax income or losses period					3 years
Unrecognized tax benefits, penalties and interest expense	$ (37,000)	$ 20,000	(33,000)	$ 60,000
Uncertain tax positions increase (decrease)			$ 0