Commitments, Off-Balance Sheet Arrangements, Legal Proceedings and Regulatory Matters (Details Textuals) - USD ($)	3 Months Ended		6 Months Ended		12 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025	Dec. 31, 2025	Jan. 01, 2022
Other Commitments [Line Items]
Investment Program, Proportional Amortization Method, Elected, Impairment Loss	$ 900,000	$ 900,000		$ 900,000
Loans Repurchased Under Make Whole Requests			$ 2,900,000		$ 3,500,000
Loans Sold To Outside Investors Loss Reimbursement Settlement Paid					0
Make Whole Requests, Loan Origination Date, Majority			Jan. 01, 2022
Loans Sold To Outside Investors Original Amount						$ 4,300,000,000
Loans Sold To Outside Investors Remaining Outstanding Amount	2,000,000,000.0		$ 2,000,000,000.0
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	50,744,000		50,744,000		41,276,000
Financing Receivable, before Allowance for Credit Loss	36,467,040,000		36,467,040,000		31,163,614,000
Loss on Sale of Investments					0
Residential Mortgage [Member]
Other Commitments [Line Items]
SEC Schedule, 12-09, Valuation Allowances and Reserves, Amount	400,000		400,000		300,000
Residential Mortgage [Member] | Recourse
Other Commitments [Line Items]
Financing Receivable, before Allowance for Credit Loss	12,200,000		12,200,000		11,400,000
Residential Mortgage [Member] | Recourse | Credit Risk
Other Commitments [Line Items]
Financing Receivable, before Allowance for Credit Loss	365,800,000		365,800,000		273,400,000
Loss on Sale of Investments			0
Affordable Housing Projects and Other [Member]
Other Commitments [Line Items]
Other Investments	161,300,000		161,300,000		174,300,000
Investment Program, Proportional Amortization Method, Applied, Amortization Expense	8,692,000	$ 8,369,000	17,146,000	$ 17,058,000
Investment, Proportional Amortization Method, Elected, Amount	160,000,000.0		160,000,000.0		172,200,000
Investment Program, Proportional Amortization Method, Elected, Impairment Loss			900,000
Investment Program, Proportional Amortization Method, Elected, Commitment	22,500,000		22,500,000		22,800,000
Loan Pool CRA Investments [Member]
Other Commitments [Line Items]
Other Investments	$ 74,300,000		$ 74,300,000		$ 62,300,000