Stockholders' Equity (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended
	Mar. 04, 2022	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021	Jan. 30, 2019
Class of Stock [Line Items]
Preferred stock, par value (in USD per share)		$ 0.01		$ 0.01
Depositary Shares [Member]
Class of Stock [Line Items]
Number of shares issued (in shares)	750,000
Liquidation preference per share (in USD per share)	$ 1,000
Ownership interest in shares	1.00%
Series K Preferred Stock [Member]
Class of Stock [Line Items]
Fixed rate	5.00%	5.00%
Preferred stock, par value (in USD per share)	$ 0.01
Liquidation preference per share (in USD per share)	$ 100,000	$ 100,000
Proceeds from offering	$ 740
Common Stock [Member]
Class of Stock [Line Items]
Share repurchase, authorized amount					$ 4,000
Shares repurchased (in shares)		0	0
Remaining amount authorized for share repurchase		$ 1,800