Derivatives - Derivative Liabilities and Collateral Pledged (Details) - USD ($) $ in Millions	Sep. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Gross amounts of recognized liabilities	$ 401	$ 655
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	401	655
Derivative assets  available for offset	(89)	(76)
Collateral pledged	(93)	(169)
Net amount	219	410
Derivative liabilities not subject to master netting agreements	23	16
Interest rate derivative contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	393	649
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	393	649
Derivative assets  available for offset	(84)	(73)
Collateral pledged	(91)	(168)
Net amount	218	408
Forward contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	8	6
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	8	6
Derivative assets  available for offset	(5)	(3)
Collateral pledged	(2)	(1)
Net amount	$ 1	$ 2