Derivatives - Derivative Liabilities and Collateral Pledged (Details) - USD ($) $ in Millions	Mar. 31, 2026	Dec. 31, 2025
Derivative [Line Items]
Gross amounts of recognized liabilities	$ 395	$ 376
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	395	376
Derivative assets  available for offset	(85)	(83)
Collateral pledged	(103)	(98)
Net amount	207	195
Derivative liabilities not subject to master netting agreements	18	26
Interest rate derivative contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	377	368
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	377	368
Derivative assets  available for offset	(77)	(79)
Collateral pledged	(103)	(94)
Net amount	197	195
Forward contracts
Derivative [Line Items]
Gross amounts of recognized liabilities	18	8
Gross amounts offset in the Balance Sheets	0	0
Net amounts of liabilities presented in the Balance Sheets	18	8
Derivative assets  available for offset	(8)	(4)
Collateral pledged	0	(4)
Net amount	$ 10	$ 0