Income Taxes - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2013	Dec. 31, 2018	Dec. 31, 2017	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 provision		$ 308,000	$ 314,000	$ 196,000
Deferred tax assets		0	0
Deferred tax liabilities		$ 0	$ 0
U.S. federal corporate income tax rate		21.00%	35.00%
Common stock, shares issued	25,875,000	14,568,431	12,421,401	1,070
Net operating losses carried forward		$ 159,000,000
NOLs expiration date		Dec. 31, 2029
Open tax year		2015 2016 2017 2018
Internal Revenue Service [Member]
Tax Credit Carryforward [Line Items]
Net operating losses limit per annum			$ 2,000,000
Net operating losses limitations			The availability of our NOLs is generally limited to $2.0 million per annum