Derivatives - Derivative Assets and Collateral Received (Details) - USD ($) $ in Millions	Sep. 30, 2023	Dec. 31, 2022
Derivative [Line Items]
Gross amounts of recognized assets	$ 861	$ 458
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	861	458
Derivative liabilities available for offset	(100)	(64)
Collateral received	(662)	(380)
Net amount	99	14
Derivative assets not subject to master netting agreements	2	2
Interest rate derivative contracts
Derivative [Line Items]
Gross amounts of recognized assets	853	449
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	853	449
Derivative liabilities available for offset	(96)	(58)
Collateral received	(662)	(378)
Net amount	95	13
Forward contracts
Derivative [Line Items]
Gross amounts of recognized assets	8	9
Gross amounts offset in the Balance Sheets	0	0
Net amounts of assets presented in the Balance Sheets	8	9
Derivative liabilities available for offset	(4)	(6)
Collateral received	0	(2)
Net amount	$ 4	$ 1