Stockholders' Equity (Preferred Stock) (Details) - USD ($) $ / shares in Units, $ in Millions				12 Months Ended
	Sep. 16, 2024	Sep. 12, 2019	Mar. 29, 2019	Dec. 31, 2019	Jun. 15, 2024	Dec. 31, 2021	Dec. 31, 2020
Class of Stock [Line Items]
Net proceeds from Issuance of Preferred Stock and Preference Stock		$ 989	$ 973	$ 1,962
Current maturities of long-term debt						$ 3,387	$ 4,238
Series A Cumulative Redeemable Perpetual Preferred Stock
Class of Stock [Line Items]
Shares issued (in shares)			40,000,000
Preferred stock, issue price (in usd per share)			$ 25
Liquidation preference per share (in usd per share)			$ 25
Cumulative annual dividend rate			5.75%
Redemption price (in usd per share)						$ 25.50
Series B Fixed-Rate Reset Cumulative Redeemable Perpetual Preferred Stock
Class of Stock [Line Items]
Shares issued (in shares)		1,000,000
Preferred stock, issue price (in usd per share)		$ 1,000
Liquidation preference per share (in usd per share)		$ 1,000
Cumulative annual dividend rate		4.875%
Redemption price (in usd per share)		$ 1,020
Forecast
Class of Stock [Line Items]
Redemption price (in usd per share)					$ 25
Forecast | Series B Fixed-Rate Reset Cumulative Redeemable Perpetual Preferred Stock
Class of Stock [Line Items]
Cumulative annual dividend rate	3.388%
Unsecured Debt | Senior notes due September 2019 | Parent Company
Class of Stock [Line Items]
Current maturities of long-term debt		$ 500