Bank Loans (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 578,980,000	$ 423,999,000
Accrued interest receivable	92,600,000	$ 94,000,000
Modifications of loans to borrowers experiencing financial difficulty	$ 116,600,000
Collateralized loan portfolio	96.80%	97.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 579,000,000	$ 424,000,000
Federal Reserve Discount Window [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	2,500,000,000
Residential Real Estate [Member] | Asset Pledged as Collateral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	7,900,000,000	7,400,000,000
Other Income [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gains (losses) recognized from sale of loans	5,000,000	1,200,000	$ 7,800,000
Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	27,700,000	25,600,000
Uncollectible broker notes		2,300,000
Credit loss reserves net	25,400,000	25,000,000
Accounting Standards Update 2016-13 [Member] | Unfunded Commitment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowances for unfunded credit commitments	2,600
Allowance for unfunded credit commitment		2,900,000
Accounting Standards Update 2016-13 [Member] | Employee Retention Awards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit loss reserves net	300,000
Stifel Bancorp [Member] | Executive Officers and Directors of Certain Affiliated Entities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	$ 39,600,000	$ 46,000,000