Shareholders' Equity - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 06, 2019	Jul. 29, 2019
Class of Stock [Line Items]
Stock and Warrants Issued During Period, Value, Preferred Stock and Warrants		$ 3,500
Preferred Stock, Value, Issued				$ 2,000
Repurchase of common stock	$ 1,616
Redemption of preferred stock	(1,415)	$ (500)	$ (1,725)
Common Stock
Class of Stock [Line Items]
Repurchase of common stock	$ 138
Repurchase of common stock (in shares)	27,609,000
Common Stock
Class of Stock [Line Items]
Stock Repurchase Program, Authorized Amount	$ 4,200
Repurchase of common stock	$ 1,600
Repurchase of common stock (in shares)	27,600,000
Common stock, remaining dollar amount authorized for repurchase	$ 2,600
Series N
Class of Stock [Line Items]
Preferred Stock, Value, Issued					$ 1,700
Series F
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	18,000
Redemption of preferred stock	$ 450
Series G
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	20,000
Redemption of preferred stock	$ 500
Series H
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	18,600
Redemption of preferred stock	$ 465
Series K
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares		5,000
Redemption of preferred stock		$ 500
Series D
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares			23,000
Series E
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares			46,000
Redeemable preferred stock
Class of Stock [Line Items]
Redemption of preferred stock			$ 1,700
Series B
Class of Stock [Line Items]
Stock Redeemed or Called During Period, Shares	1,000
Redemption of preferred stock	$ 100