Stockholders’ Equity - (Summary of Distributions) (Details) - $ / shares	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Dividends Payable [Line Items]
Dividends, percent	100.00%	100.00%	100.00%
Dividends (in usd per share)	$ 1.10	$ 1.10	$ 1.47
Return of capital
Dividends Payable [Line Items]
Dividends, percent	90.20%	93.20%	82.70%
Dividends (in usd per share)	$ 0.99	$ 1.03	$ 1.22
Ordinary dividend income
Dividends Payable [Line Items]
Dividends, percent	9.80%	6.80%	17.30%
Dividends (in usd per share)	$ 0.11	$ 0.07	$ 0.25