Fair Value of Assets and Liabilities - Summary Of Differences Between The Fair Value Carrying Amount Of Mortgages Held-For-Sale And Aggregate Unpaid Principal Amount (Details) - USD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	$ 51	$ 258
Held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	51	258
Fair value carrying amount less aggregate unpaid principal - Total loans	(7)	(6)
Nonaccrual loans	5	4
Fair value carrying amount less aggregate unpaid principal - Nonaccrual loans	(3)	(3)
Loans 90 days or more past due and still accruing	1
Fair value carrying amount less aggregate unpaid principal - Loans 90 days or more past due and still accruing	0
Aggregate unpaid principal | Held for sale
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation [Line Items]
Loans held-for-sale	58	264
Nonaccrual loans	8	$ 7
Loans 90 days or more past due and still accruing	$ 1