Derivative Instruments - Schedule of Collateral Amounts With Rights to Reclaim or Obligation to Return Cash (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	$ 6,352	$ 7,784
Collateral Posted to Counterparty	(311)	(19)
AA-
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	2,072	2,868
Collateral Posted to Counterparty	(129)	(4)
A+
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	3,836	4,612
Collateral Posted to Counterparty	(182)	(15)
A
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	43	64
Collateral Posted to Counterparty	0	0
A-
Credit Derivatives [Line Items]
Collateral Posted by Counterparty	401	240
Collateral Posted to Counterparty	$ 0	$ 0