Derivative Instruments - Schedule of Collateral Amounts With Rights to Reclaim or Obligation to Return Cash (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	$ 8,714	$ 7,039
Collateral Posted to Counterparty	(34)	(91)
AA-
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	3,365	4,006
Collateral Posted to Counterparty	(5)	(2)
A+
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	4,606	2,354
Collateral Posted to Counterparty	(29)	(89)
A
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	70	47
Collateral Posted to Counterparty	0	0
A-
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	673	632
Collateral Posted to Counterparty	$ 0	$ 0