Derivative Financial Instruments and Off-balance Sheet Financial Instruments - Schedule of Volume and Fair Value Positions of Derivative Instruments (Details) $ in Millions	Dec. 31, 2023 USD ($) contract	Dec. 31, 2022 USD ($) contract
Derivatives, Fair Value
Total asset derivatives, notional amount	$ 562	$ 628
Total liability derivatives, notional amount	325	808
Total derivatives, notional amount	$ 887	$ 1,436
Total asset derivatives, number of contracts | contract	21,816,000,000	24,723
Total liability derivatives, number of contracts | contract	3,155,000,000	2,853
Total derivatives, number of contracts | contract	24,971,000,000	27,576
Total asset derivatives, fair value, net	$ 118	$ 107
Total liabilty derivatives, fair value, net	(6)	(4)
Total derivatives, fair value, net	112	103
Asset derivatives, gross asset	123	121
Liability derivatives, gross asset	1	8
Asset derivatives, gross liability	(5)	(14)
Liability derivatives, gross liability	$ (7)	$ (12)
Derivative Asset, Statement of Financial Position [Extensible Enumeration]	Other assets, net, Other investments, net	Other assets, net, Other investments, net
Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total liability derivatives, number of contracts | contract		1,624
Total liabilty derivatives, fair value, net		$ 0
Liability derivatives, gross asset		0
Liability derivatives, gross liability		$ 0
Interest rate contracts, futures | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	20,479,000,000	24,380
Total liability derivatives, number of contracts | contract	2,175,000,000
Total asset derivatives, fair value, net	$ 2	$ 3
Total liabilty derivatives, fair value, net	(1)
Asset derivatives, gross asset	2	3
Liability derivatives, gross asset	0
Asset derivatives, gross liability	0	$ 0
Liability derivatives, gross liability	$ (1)
Equity and index contracts, options | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	32,000,000
Total asset derivatives, fair value, net	$ 0
Asset derivatives, gross asset	0
Asset derivatives, gross liability	$ 0
Equity and index contracts, futures | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, number of contracts | contract	1,305,000,000	343
Total liability derivatives, number of contracts | contract	980,000,000	1,229
Total asset derivatives, fair value, net	$ 1	$ 0
Total liabilty derivatives, fair value, net	(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 forwards | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	278	354
Total liability derivatives, notional amount	306	283
Total asset derivatives, fair value, net	(2)	1
Total liabilty derivatives, fair value, net	(3)	0
Asset derivatives, gross asset	2	14
Liability derivatives, gross asset	1	7
Asset derivatives, gross liability	(4)	(13)
Liability derivatives, gross liability	(4)	(7)
Contingent consideration | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	250	250
Total asset derivatives, fair value, net	118	103
Asset derivatives, gross asset	118	103
Asset derivatives, gross liability	0	0
Credit default swaps – buying protection | Derivatives not designated as accounting hedging instruments
Derivatives, Fair Value
Total asset derivatives, notional amount	34	24
Total liability derivatives, notional amount	19	525
Total asset derivatives, fair value, net	(1)	0
Total liabilty derivatives, fair value, net	(1)	(3)
Asset derivatives, gross asset	0	1
Liability derivatives, gross asset	0	1
Asset derivatives, gross liability	(1)	(1)
Liability derivatives, gross liability	$ (1)	$ (4)