Dividends and Distributions - Distribution Type (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Common Shares
Ordinary income	66.00%	85.00%	100.00%
Capital gains	0.00%	0.00%	0.00%
Return of capital	34.00%	15.00%	0.00%
Total	100.00%	100.00%	100.00%
Preferred Shares
Ordinary income	100.00%	100.00%	100.00%
Capital gains	0.00%	0.00%	0.00%
Return of capital	0.00%	0.00%	0.00%
Total	100.00%	100.00%	100.00%