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, 2023 USD ($) contract	Dec. 31, 2022 USD ($) contract
Derivatives, Fair Value
Total asset derivatives, notional amount	$ 554	$ 628
Total liability derivatives, notional amount	921	808
Total derivatives, notional amount	$ 1,475	$ 1,436
Total asset derivatives, number of contracts | contract	11,577	24,723
Total liability derivatives, number of contracts | contract	7,307	2,853
Total derivatives, Number of contracts | contract	18,884	27,576
Net amount on balance sheet	$ 118	$ 107
Net amount on balance sheet	4	(4)
Total derivatives, fair value, net	122	103
Asset derivatives, gross asset	120	121
Liability derivatives, gross asset	15	8
Asset derivatives, gross liability	(2)	(14)
Liability derivatives gross liability	$ (11)	$ (12)
Interest rate contracts
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	10,126	24,380
Total liability derivatives, number of contracts | contract	5,312	1,624
Net amount on balance sheet	$ 1	$ 3
Net amount on balance sheet	(2)	0
Asset derivatives, gross asset	1	3
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross liability	$ (2)	$ 0
Equity and index contracts
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	1,451	343
Total liability derivatives, number of contracts | contract	1,995	1,229
Net amount on balance sheet	$ 1	$ 0
Net amount on balance sheet	(1)	(1)
Asset derivatives, gross asset	1	0
Liability derivatives, gross asset	0	0
Asset derivatives, gross liability	0	0
Liability derivatives gross liability	(1)	(1)
Foreign currency contracts
Derivatives, Fair Value
Total asset derivatives, notional amount	267	354
Total liability derivatives, notional amount	354	283
Net amount on balance sheet	3	1
Net amount on balance sheet	12	0
Asset derivatives, gross asset	5	14
Liability derivatives, gross asset	14	7
Asset derivatives, gross liability	(2)	(13)
Liability derivatives gross liability	(2)	(7)
Contingent consideration
Derivatives, Fair Value
Total asset derivatives, notional amount	250	250
Net amount on balance sheet	113	103
Asset derivatives, gross asset	113	103
Asset derivatives, gross liability	0	0
Credit default contracts
Derivatives, Fair Value
Total asset derivatives, notional amount	37	24
Total liability derivatives, notional amount	567	525
Net amount on balance sheet	0	0
Net amount on balance sheet	(5)	(3)
Asset derivatives, gross asset	0	1
Liability derivatives, gross asset	1	1
Asset derivatives, gross liability	0	(1)
Liability derivatives gross liability	$ (6)	$ (4)