Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters (Details Textuals) - USD ($)	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Expense Related to Qualified Affordable Housing Projects	$ 9,000,000	$ 9,000,000	$ 26,000,000	$ 25,000,000
Remaining Investment in Qualified Affordable Housing Projects	219,000,000		219,000,000		$ 246,000,000
Variable Interest Entity Reporting Entity Involvement Unfunded Obligation Amount	27,000,000		27,000,000		40,000,000
Qualified Affordable Housing Investments, Impairment Loss			0		0
Loans Repurchased Under Make Whole Requests	5,000,000		$ 5,000,000		6,000,000
Loans Sold To Outside Investors Loss ReimbursementSettlement Paid					0
Make Whole Requests, Loan Origination Date, Majority			Jan. 01, 2020
Loans Sold To Outside Investors Original Amount	4,600,000,000		$ 4,600,000,000
Loans Sold To Outside Investors Remaining Outstanding Amount	3,300,000,000		3,300,000,000
Mortgage Repurchase Reserve	680,000		680,000		1,000,000
Residential Mortgage Loans Sold With Recourse Risk	15,000,000		15,000,000		7,000,000
Residential Mortgage Loans Sold With Credit Recourse Risk	17,000,000		17,000,000		19,000,000
Residential Mortgage Loans with Credit Risk Recourse	0		0		0
UnconsolidatedProjectsLowIncomeHousing [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	222,000,000		222,000,000		250,000,000
PrincipalInvestmentCommitment [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	$ 34,000,000		$ 34,000,000		$ 27,000,000