Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters (Details Textuals) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2023	Mar. 31, 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	$ 8,000,000
Remaining Investment in Qualified Affordable Housing Projects	237,000,000		$ 246,000,000
Variable Interest Entity Reporting Entity Involvement Unfunded Obligation Amount	34,000,000		40,000,000
Qualified Affordable Housing Investments, Impairment Loss	0		0
Loans Repurchased Under Make Whole Requests	2,000,000		6,000,000
Loans Sold To Outside Investors Original Amount	2,500,000,000
Loans Sold To Outside Investors Remaining Outstanding Amount	2,100,000,000
Mortgage Repurchase Reserve	566,000		1,000,000
Residential Mortgage Loans Sold With Recourse Risk	7,000,000
Residential Mortgage Loans Sold With Credit Recourse Risk	18,000,000		19,000,000
Residential Mortgage Loans with Credit Risk Recourse	0
SBA Loan Fund, Remaining Unfunded Equity Contribution	$ 5,000,000
Make Whole Requests, Loan Origination Date, Majority	Jan. 01, 2021
UnconsolidatedProjectsLowIncomeHousing [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	$ 241,000,000		250,000,000
PrincipalInvestmentCommitment [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	$ 28,000,000		$ 27,000,000