Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2013	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
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 (benefit) provision		$ 83,000	$ 194,000	$ 265,000	$ 281,000
Deferred tax assets		0		0		$ 0
Deferred tax liabilities		$ 0		$ 0		0
Common stock, shares issued	25,875,000			971	812
Net operating losses carried forward						$ 159,000,000
NOLs expiration date				Dec. 31, 2029
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses limitations				The availability of our NOLs is generally limited to $2.0 million per annum
Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year				2014
Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year				2016