Fair Value Measurements - Schedule of Change in Fair Values of Level 3 Financial Instruments (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2024	Jun. 30, 2023	Jun. 30, 2024	Jun. 30, 2023
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	$ 2	$ 2	$ 2	$ 2
Gains (Losses) Included in Other Comprehensive Income	0	0	0	0
Gains (Losses) Included in Earnings	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
End of Period Balance	2	2	2	2
Unrealized Gains (Losses) Included in Earnings	0	0	0	0
Direct
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance		1		1
Gains (Losses) Included in Other Comprehensive Income		0		0
Gains (Losses) Included in Earnings		0		0
Purchases		0		0
Sales		0		0
Settlements		0		0
Transfers Other		0		0
Transfers into Level 3		0		0
Transfers out of Level 3		0		0
End of Period Balance		1		1
Unrealized Gains (Losses) Included in Earnings		0		0
Interest rate
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	0	13	(2)	2
Gains (Losses) Included in Other Comprehensive Income	0	0	0	0
Gains (Losses) Included in Earnings	(2)	(23)	(6)	(17)
Purchases	0	0	1	18
Sales	0	1	0	0
Settlements	0	0	0	0
Transfers Other	0	0	0	0
Transfers into Level 3	(1)	5	1	(2)
Transfers out of Level 3	1	9	4	4
End of Period Balance	(2)	5	(2)	5
Unrealized Gains (Losses) Included in Earnings	0	0	0	0
Credit
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance		(2)		(2)
Gains (Losses) Included in Other Comprehensive Income		0		0
Gains (Losses) Included in Earnings		0		0
Purchases		0		0
Sales		2
Settlements		0		0
Transfers Other		0		0
Transfers into Level 3		0		0
Transfers out of Level 3		0
End of Period Balance		0		0
Unrealized Gains (Losses) Included in Earnings		0		0
Other
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	2	1	2	0
Gains (Losses) Included in Other Comprehensive Income	0	0	0	0
Gains (Losses) Included in Earnings	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers Other	(1)	0	(1)	1
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	0	0	0	0
End of Period Balance	1	1	1	1
Unrealized Gains (Losses) Included in Earnings	0	0	0	0
Loans, net of unearned income (residential)
Fair Value, Net Derivative Asset (Liability) Measured on Recurring Basis, Unobservable Input Reconciliation [Roll Forward]
Beginning of Period Balance	9	9	9	9
Gains (Losses) Included in Other Comprehensive Income	0	0	0	0
Gains (Losses) Included in Earnings	0	0	0	0
Purchases	0	0	0	0
Sales	0	0	0	0
Settlements	0	0	0	0
Transfers Other	0	0	0	0
Transfers into Level 3	0	0	0	0
Transfers out of Level 3	2	0	2	0
End of Period Balance	11	9	11	9
Unrealized Gains (Losses) Included in Earnings	$ 0	$ 0	$ 0	$ 0