Derivative Financial Instruments - Schedule of Volume and Fair Value Positions of Derivative Instruments (Details) - Derivatives not designated as accounting hedging instruments $ in Millions	Mar. 31, 2024 USD ($) contract	Dec. 31, 2023 USD ($) contract
Derivatives, Fair Value
Total asset derivatives, notional amount	$ 476	$ 562
Total liability derivatives, notional amount	395	325
Total derivatives, notional amount	$ 871	$ 887
Total asset derivatives, number of contracts | contract	5,573	21,816
Total liability derivatives, number of contracts | contract	11,915	3,155
Total derivatives, Number of contracts | contract	17,488	24,971
Net amount on balance sheet	$ 122	$ 118
Net amount on balance sheet	(2)	(6)
Total derivatives, fair value, net	120	112
Asset derivatives, gross asset	123	123
Liability derivatives, gross asset	3	1
Asset derivatives, gross liability	(1)	(5)
Liability derivatives gross liability	$ (5)	$ (7)
Interest rate contracts
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	4,644	20,479
Total liability derivatives, number of contracts | contract	11,163	2,175
Net amount on balance sheet	$ 1	$ 2
Net amount on balance sheet	(2)	(1)
Asset derivatives, gross asset	1	2
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross liability	$ (2)	$ (1)
Options
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	16	32
Total liability derivatives, number of contracts | contract	16
Net amount on balance sheet	$ 0	$ 0
Net amount on balance sheet	0
Asset derivatives, gross asset	0	0
Liability derivatives, gross asset	0
Asset derivatives, gross liability	0	$ 0
Liability derivatives gross liability	$ 0
Futures
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	913	1,305
Total liability derivatives, number of contracts | contract	736	980
Net amount on balance sheet	$ 0	$ 1
Net amount on balance sheet	0	(1)
Asset derivatives, gross asset	0	1
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross liability	0	(1)
Foreign currency contracts
Derivatives, Fair Value
Total asset derivatives, notional amount	183	278
Total liability derivatives, notional amount	384	306
Net amount on balance sheet	2	(2)
Net amount on balance sheet	1	(3)
Asset derivatives, gross asset	2	2
Liability derivatives, gross asset	3	1
Asset derivatives, gross liability	0	(4)
Liability derivatives gross liability	(2)	(4)
Contingent consideration
Derivatives, Fair Value
Total asset derivatives, notional amount	250	250
Net amount on balance sheet	120	118
Asset derivatives, gross asset	120	118
Asset derivatives, gross liability	0	0
Credit default contracts
Derivatives, Fair Value
Total asset derivatives, notional amount	43	34
Total liability derivatives, notional amount	11	19
Net amount on balance sheet	(1)	(1)
Net amount on balance sheet	(1)	(1)
Asset derivatives, gross asset	0	0
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	(1)	(1)
Liability derivatives gross liability	$ (1)	$ (1)