Bank Loans (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024	Dec. 31, 2024	Dec. 21, 2024
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 800,766		$ 800,766		$ 578,980
Accrued interest receivable	$ 90,600		$ 90,600			$ 92,600
Collateralized loan portfolio	969.00%		969.00%		968.00%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 800,800		$ 800,800		$ 579,000
Federal Reserve Discount Window [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	2,600,000		2,600,000		2,500,000
Residential Real Estate [Member] | Asset Pledged as Collateral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	8,200,000		8,200,000		7,900,000
Other Income [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Gains (losses) recognized from sale of loans	(4,200)	$ (1,500)	(4,800)	$ (2,900)
Accounting Standards Update 2016-13 [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowance for credit losses	7,900	6,800	20,400	11,400
Credit loss reserves net	8,300	3,000	20,300	8,200
Accounting Standards Update 2016-13 [Member] | Unfunded Commitment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Allowances for unfunded credit commitments	400	$ 3,900	100	3,500
Accounting Standards Update 2016-13 [Member] | Employee Retention Awards [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Credit loss reserves net				$ 300
Stifel Bancorp [Member] | Executive Officers and Directors of Certain Affiliated Entities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	$ 47,600		$ 47,600		$ 39,600