Basis of Presentation and Significant Accounting Policies - Summary of Characterization of Dividend Distributions for Federal Income Tax Purposes (Details) - $ / shares			1 Months Ended	12 Months Ended
	Jan. 13, 2017	Jan. 15, 2016	Dec. 31, 2014	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Taxes [Line Items]
Cash dividend	$ 0.095	$ 0.095	$ 0.039	$ 0.380	$ 0.380	$ 0.324
Return of capital				48.70%	71.80%	89.20%
Ordinary income				51.30%	28.20%	10.80%
Total				100.00%	100.00%	100.00%
Return of Capital
Income Taxes [Line Items]
Cash dividend				$ 0.185	$ 0.273	$ 0.289
Ordinary Income
Income Taxes [Line Items]
Cash dividend				$ 0.195	$ 0.107	$ 0.035