Other Equity Matters - Preferred Share (Details) - USD ($)	Sep. 30, 2020	Jan. 31, 2020	Nov. 30, 2019	Jun. 30, 2019	Mar. 31, 2019
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value	$ 555,000,000
Preferred Stock, Liquidation Preference Per Share	$ 22,200,000,000
8.50% Series A Cumulative Redeemable Perpetual Preference Shares
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value					$ 86,250,000
Preferred Stock, Liquidation Preference Per Share					$ 3,450,000,000
8.00% Series B Cumulative Redeemable Perpetual Preference Shares
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value				$ 143,750,000
Preferred Stock, Liquidation Preference Per Share				$ 5,750,000,000
7.375% Series C Cumulative Redeemable Perpetual Preference Shares
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value			$ 175,000,000
Preferred Stock, Liquidation Preference Per Share			$ 7,000,000,000
6.875% Series D Cumulative Redeemable Perpetual Preference Shares
Class of Stock [Line Items]
Preferred Stock, Liquidation Preference, Value		$ 150,000,000
Preferred Stock, Liquidation Preference Per Share		$ 6,000,000,000