Equity - Distributions Paid on a Percentage Basis (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Class of Stock [Line Items]
Ordinary dividends	45.00%	13.80%	60.00%
Nondividend distributions	37.20%	86.20%	37.00%
Capital gain distributions	17.80%	0.00%	3.00%
Total	100.00%	100.00%	100.00%
Series F Preferred Stock [Member]
Class of Stock [Line Items]
Ordinary dividends	71.70%	100.00%	95.00%
Capital gain distributions	28.30%	0.00%	5.00%
Total	100.00%	100.00%	100.00%