Derivative Financial Instruments - Schedule of Volume and Fair Value Positions of Derivative Instruments (Details) - Derivatives not designated as accounting hedging instruments $ in Millions	Sep. 30, 2024 USD ($) contract	Dec. 31, 2023 USD ($) contract
Derivatives, Fair Value
Total asset derivatives, notional amount	$ 663	$ 562
Total liability derivatives, notional amount	262	325
Total derivatives, notional amount	$ 925	$ 887
Total asset derivatives, number of contracts | contract	4,565	21,816
Total liability derivatives, number of contracts | contract	22,390	3,155
Total derivatives, Number of contracts | contract	26,955	24,971
Net amount on balance sheet	$ 117	$ 118
Net amount on balance sheet	(16)	(6)
Total derivatives, fair value, net	101	112
Asset derivatives, gross asset	126	123
Liability derivatives, gross asset	0	1
Asset derivatives, gross liability	(9)	(5)
Liability derivatives gross liability	$ (16)	$ (7)
Interest rate contracts
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	3,520	20,479
Total liability derivatives, number of contracts | contract	22,106	2,175
Net amount on balance sheet	$ 1	$ 2
Net amount on balance sheet	(9)	(1)
Asset derivatives, gross asset	1	2
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross liability	$ (9)	$ (1)
Options
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract		32
Net amount on balance sheet		$ 0
Asset derivatives, gross asset		0
Asset derivatives, gross liability		$ 0
Futures
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	1,045	1,305
Total liability derivatives, number of contracts | contract	284	980
Net amount on balance sheet	$ 1	$ 1
Net amount on balance sheet	0	(1)
Asset derivatives, gross asset	1	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	383	278
Total liability derivatives, notional amount	262	306
Net amount on balance sheet	(8)	(2)
Net amount on balance sheet	(7)	(3)
Asset derivatives, gross asset	1	2
Liability derivatives, gross asset	0	1
Asset derivatives, gross liability	(9)	(4)
Liability derivatives gross liability	(7)	(4)
Contingent consideration
Derivatives, Fair Value
Total asset derivatives, notional amount	250	250
Net amount on balance sheet	123	118
Asset derivatives, gross asset	123	118
Asset derivatives, gross liability	0	0
Credit default contracts
Derivatives, Fair Value
Total asset derivatives, notional amount	30	34
Total liability derivatives, notional amount		19
Net amount on balance sheet	0	(1)
Net amount on balance sheet		(1)
Asset derivatives, gross asset	0	0
Liability derivatives, gross asset		0
Asset derivatives, gross liability	$ 0	(1)
Liability derivatives gross liability		$ (1)