Derivatives - Derivative Assets and Collateral Received (Details) - USD ($) $ in Millions	Jun. 30, 2025	Dec. 31, 2024
Derivative [Line Items]
Gross amounts of recognized assets	$ 383	$ 530
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	383	530
Derivative liabilities available for offset	(87)	(76)
Collateral received	(271)	(440)
Net amount	25	14
Derivative assets not subject to master netting agreements (current year less than)	1	2
Interest rate derivative contracts
Derivative [Line Items]
Gross amounts of recognized assets	373	522
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	373	522
Derivative liabilities available for offset	(83)	(73)
Collateral received	(270)	(436)
Net amount	20	13
Forward contracts
Derivative [Line Items]
Gross amounts of recognized assets	10	8
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	10	8
Derivative liabilities available for offset	(4)	(3)
Collateral received	(1)	(4)
Net amount	$ 5	$ 1