Derivative Financial Instruments - Schedule of Gross and Net Amounts for OTC Derivatives (Details) - OTC derivatives - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Asset derivatives
Gross amount	$ 2	$ 21
Counter-party netting	(2)	(1)
Cash collateral (received) pledged	0	(18)
Net amount on balance sheet	0	2
Securities collateral (received) pledged	0	0
Net amount	0	2
Liability derivatives
Gross amount	(32)	(1)
Counter-party netting	2	1
Cash collateral (received) pledged	28	0
Net amount on balance sheet	(2)	0
Securities collateral (received) pledged	0	0
Net amount	$ (2)	$ 0