Equity - Preferred Stock Outstanding and Dividends (Details) - $ / shares		3 Months Ended				12 Months Ended
	Nov. 30, 2018	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2019	Dec. 31, 2018
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		20,400,000				20,400,000	20,400,000
Series C Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		5,000,000				5,000,000	5,000,000
Preferred stock, dividend rate, percentage						6.50%
Dividend per share/unit (in usd per share)		$ 0.41	$ 0.41	$ 0.41	$ 0.41
Series D Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		5,000,000				5,000,000	5,000,000
Preferred stock, dividend rate, percentage						6.375%
Dividend per share/unit (in usd per share)		$ 0.40	0.40	0.40	0.40
Series E Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		4,400,000				4,400,000	4,400,000
Preferred stock, dividend rate, percentage	6.375%					6.375%
Dividend per share/unit (in usd per share)		$ 0.40	0.40	0.40	0.40
Series F Cumulative Redeemable Preferred Shares
Class of Stock [Line Items]
Preferred stock, outstanding (in shares)		6,000,000				6,000,000	6,000,000
Preferred stock, dividend rate, percentage	6.30%					6.30%
Dividend per share/unit (in usd per share)		$ 0.39	$ 0.39	$ 0.39	$ 0.39