Income Taxes - Reconciliation of Income Tax Computed at U.S. Federal Statutory Rate to Income Tax Expense (Benefit) (Detail) (USD $)	3 Months Ended	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Income Tax Disclosure [Abstract]
Tax expense (benefit) at U.S. statutory rate, Amount		$ 2,610,000	$ 1,492,000	$ (3,399,000)
State and local tax expense (benefit), net of Federal impact, Amount		194,000	86,000	(96,000)
Impact of state and local tax rate change net of Federal impact, Amount		27,000	110,000	6,000
Cost (benefit) attributable to valuation allowance, net, Amount		0	(150,000)	3,671,000
Non-deductible items, Amount		11,000	9,000	5,000
Benefit attributable to reduction in allowance against certain deferred tax assets, Amount		0	(15,217,000)	(5,614,000)
Income tax expense (benefit)	$ (14,751,000)	$ 2,842,000	$ (13,670,069)	$ (5,427,000)
Tax expense (benefit) at U.S. statutory rate, Percent		35.00%	35.00%	(35.00%)
State and local tax expense (benefit), net of Federal impact, Percent		2.60%	2.01%	(0.99%)
Impact of state and local tax rate change net of Federal impact, Percent		0.36%	2.58%	0.06%
Cost (benefit) attributable to valuation allowance, net, Percent		0.00%	(3.52%)	37.80%
Non-deductible items, Percent		0.15%	0.21%	0.05%
Benefit attributable to reduction in allowance against certain deferred tax assets, Percent		0.00%	(356.94%)	(57.81%)
Income tax expense (benefit), Percent		38.11%	(320.66%)	(55.89%)