Stockholders' Equity (Details) - USD ($) $ / shares in Units, $ in Millions			3 Months Ended	6 Months Ended
	Jul. 30, 2020	May 27, 2020	Jun. 30, 2020	Jun. 30, 2020	Jun. 30, 2019	Dec. 31, 2019
Class of Stock [Line Items]
Preferred Stock, Shares Authorized			50,000,000	50,000,000		50,000,000
Preferred Stock, Shares Issued			10,062,500	10,062,500
Common Stock, Shares Authorized			2,000,000,000	2,000,000,000		2,000,000,000
Common Stock, Par or Stated Value Per Share			$ 0.01	$ 0.01		$ 0.01
Net proceeds from issuance of common stock in connection with public offering				$ 975	$ 0
Preferred Stock
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues			10,062,500
Common Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues			29,382,500
5.50% MCPS, Series A [Member] | Preferred Stock
Class of Stock [Line Items]
Preferred Stock, Shares Issued		10,062,500
Preferred Stock, Dividend Rate, Percentage				5.50%
Preferred Stock, Liquidation Preference Per Share		$ 100	$ 100	$ 100
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 975
Preferred Stock, Liquidation Preference, Value			$ 1,006	$ 1,006
Distributed Earnings				$ 5
5.50% MCPS, Series A [Member] | Preferred Stock | Minimum [Member]
Class of Stock [Line Items]
Convertible Preferred Stock, Terms of Conversion				2.3834
5.50% MCPS, Series A [Member] | Preferred Stock | Maximum [Member]
Class of Stock [Line Items]
Convertible Preferred Stock, Terms of Conversion				2.9197
5.50% MCPS, Series A [Member] | Preferred Stock | Subsequent Event [Member]
Class of Stock [Line Items]
Preferred Stock, Dividends, Per Share, Cash Paid	$ 1.4361
Dividends, Preferred Stock, Cash	$ 14
Common Stock [Member]
Class of Stock [Line Items]
Stock Issued During Period, Shares, New Issues		29,382,500
Shares Issued, Price Per Share		$ 34.25
Common Stock [Member] | Common Stock [Member]
Class of Stock [Line Items]
Net proceeds from issuance of common stock in connection with public offering		$ 975