Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters (Details Textuals) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021	Dec. 31, 2021
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Expense Related to Qualified Affordable Housing Projects	$ 8,000,000	$ 8,000,000	$ 16,000,000	$ 16,000,000
Remaining Investment in Qualified Affordable Housing Projects	245,000,000		245,000,000		$ 262,000,000
Variable Interest Entity Reporting Entity Involvement Unfunded Obligation Amount	44,000,000		44,000,000		80,000,000
Qualified Affordable Housing Investments, Impairment Loss			0		0
Loans Repurchased Under Make Whole Requests	3,000,000		3,000,000		8,000,000
Loans Sold To Outside Investors Loss ReimbursementSettlement Paid					114,000
Loans Sold To Outside Investors Original Amount	7,400,000,000		7,400,000,000
Loans Sold To Outside Investors Remaining Outstanding Amount	4,600,000,000		4,600,000,000
Mortgage Repurchase Reserve	1,000,000		1,000,000		1,000,000
Residential Mortgage Loans Sold With Recourse Risk	7,000,000		7,000,000		10,000,000
Residential Mortgage Loans Sold With Credit Recourse Risk	22,000,000		22,000,000		24,000,000
Residential Mortgage Loans with Credit Risk Recourse	0		0
UnconsolidatedProjectsLowIncomeHousing [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	250,000,000		250,000,000		268,000,000
PrincipalInvestmentCommitment [Member]
Commitments, Off-Balance Sheet Arrangements, and Contingent Liabilities (Textuals) [Line Items]
Other Investments	$ 25,000,000		$ 25,000,000		$ 25,000,000