Derivatives - Derivative Assets and Collateral Received (Details) - USD ($) $ in Millions	Mar. 31, 2024	Dec. 31, 2023
Derivative [Line Items]
Gross amounts of recognized assets	$ 650	$ 576
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	650	576
Derivative liabilities available for offset	(78)	(79)
Collateral received	(553)	(489)
Net amount	19	8
Derivative assets not subject to master netting agreements	1	1
Interest rate derivative contracts
Derivative [Line Items]
Gross amounts of recognized assets	645	567
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	645	567
Derivative liabilities available for offset	(76)	(75)
Collateral received	(553)	(486)
Net amount	16	6
Forward contracts
Derivative [Line Items]
Gross amounts of recognized assets	5	9
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	5	9
Derivative liabilities available for offset	(2)	(4)
Collateral received	0	(3)
Net amount	$ 3	$ 2