Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
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		$ 196,000	$ 504,000	$ 518,000
Deferred tax assets		0	0
Deferred tax liabilities		0	$ 0
Net operating losses carried forward		$ 159,000,000
NOLs expiration date		Dec. 31, 2029
Common stock, shares issued	25,875,000	1,070	34,780,622	28,275,006
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses limitations		The availability of our then outstanding NOLs is generally limited to $2.0 million per annum
Earliest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year		2013
Latest Tax Year [Member]
Tax Credit Carryforward [Line Items]
Open tax year		2016