Debt - Debt Redemption and Issuance Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	Feb. 28, 2022	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Line of Credit Facility [Line Items]
Redemption price				$ 3,108	$ 2,200
Loss on extinguishment of debt		$ (47)	$ 0	(120)	(128)
Debt issued		16,350		16,350		$ 18,270
Senior Notes
Line of Credit Facility [Line Items]
Debt redeemed		970		2,390	1,990
Redemption price		$ 1,010		$ 2,490	$ 2,110
5.875% Junior Subordinated Debentures due 2057
Line of Credit Facility [Line Items]
Redemption price	$ 520
Stated interest rate		5.875%		5.875%
6.375% Junior Subordinated Debentures due 2062
Line of Credit Facility [Line Items]
Stated interest rate		6.375%		6.375%
Debt issued		$ 1,000		$ 1,000
Interest rate, reset period				5 years
6.375% Junior Subordinated Debentures due 2062 | US Treasury Rate | From March 30, 2027
Line of Credit Facility [Line Items]
Basis spread on variable rate				3.999%
6.375% Junior Subordinated Debentures due 2062 | US Treasury Rate | From March 30, 2032
Line of Credit Facility [Line Items]
Basis spread on variable rate				4.249%
6.375% Junior Subordinated Debentures due 2062 | US Treasury Rate | From March 30, 2047
Line of Credit Facility [Line Items]
Basis spread on variable rate				4.999%
6.25% Junior Subordinated Debentures due 2057
Line of Credit Facility [Line Items]
Stated interest rate		6.25%		6.25%
6.25% Junior Subordinated Debentures due 2057 | London Interbank Offered Rate (LIBOR) | From March 1, 2027
Line of Credit Facility [Line Items]
Basis spread on variable rate				3.899%