Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended								12 Months Ended
	Jun. 30, 2015	May. 31, 2015	Apr. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Apr. 30, 2014	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Tax Credit Carryforward [Line Items]
Annual distribution of net taxable income for U.S. federal income tax not to apply to our earnings that we distribute (percent)									90.00%
Net taxable income subject to distribution (percent)									100.00%
Excise tax rate									4.00%
Income tax provision									$ 504,000	$ 518,000	$ 995,000
Deferred tax assets				$ 0					0	0
Deferred tax liabilities				$ 0					0	$ 0
Net operating losses carried forward									159,000,000
Net capital losses carried forward									$ 602,000
NOLs expiration date									Dec. 31, 2029
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses and net capital losses									$ 2,000,000
Class A Common Stock [Member]
Tax Credit Carryforward [Line Items]
Common stock, shares issued	11,500,000	280,025	23,000,000	100,000	9,200,000	9,200,000	9,775,000	25,875,000	34,780,025	28,275,000
Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year									2012
Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year									2015