Derivative Financial Instruments - Schedule of Gains (Losses) from Valuation and Settlements Reported on Derivatives Not Designated as Accounting Hedges (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	$ 24	$ 32	$ (51)	$ 26
Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	6	20	(78)	(3)
Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	18	12	27	29
Interest rate contracts
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	2	42	(8)	21
Interest rate contracts | Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	2	42	(8)	21
Interest rate contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	0	0	0	0
Equity and index contracts
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	13	8	11	7
Equity and index contracts | Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	(2)	(2)	(10)	(17)
Equity and index contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	15	10	21	24
Contingent consideration
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	3	2	6	5
Contingent consideration | Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	0	0	0	0
Contingent consideration | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	3	2	6	5
Foreign currency contracts
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	6	(23)	(50)	(9)
Foreign currency contracts | Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	6	(23)	(50)	(9)
Foreign currency contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives	$ 0	0	0	0
Credit default contracts
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives		3	(10)	2
Credit default contracts | Net gains (losses) on investments and derivatives
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives		3	(10)	2
Credit default contracts | Operating costs and expenses
Derivative Instruments, Gain (Loss)
Gains (losses) from valuation and settlements reported on derivatives		$ 0	$ 0	$ 0