Fair Value Measurements - Changes in Level 3 Financial Assets and Financial Liabilities Carried at Fair Value (Details) - USD ($) $ in Millions	3 Months Ended	9 Months Ended
Sep. 30, 2024	Sep. 30, 2023	Sep. 30, 2024	Sep. 30, 2023
Transfers into / (out of) Level 3
Change in unrealized gain or (loss) included in Other comprehensive income (loss) for assets held at the end of the reporting period	$ 8	$ (4)	$ 3	$ (9)
Debt and Equity Securities
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning balance		454		447
Beginning balance, including held for sale assets	397		447
Losses included in Shareholders' net income	(10)	(1)	(71)	(1)
Gains (losses) included in Other comprehensive income (loss)	8	(5)	3	(5)
Purchases, sales and settlements
Purchases	4	6	15	10
Sales	(2)	0	(2)	0
Settlements	(4)	(5)	(19)	(32)
Total purchases, sales and settlements	(2)	1	(6)	(22)
Transfers into / (out of) Level 3
Transfers into Level 3	32	0	63	71
Transfers out of Level 3	(2)	(13)	(13)	(54)
Total transfers into / (out of) Level 3	30	(13)	50	17
Ending balance		436		436
Ending balance, including held for sale assets	423		423
Total losses included in Shareholders' net income attributable to instruments held at the reporting date	$ (9)	$ (1)	$ (71)	$ (1)

This element represents total gains or losses for the period (realized and unrealized), arising from assets included in income attributable to instruments held at the reporting date, measured at fair value on a recurring basis using unobservable inputs (Level 3), which are included in earnings or resulted in a change in asset value.

No definition available.