Bank Loans (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 234,927		$ 234,927		$ 207,715
Gains (losses) recognized from sale of loans	400	$ 4,400	1,000	$ 25,800
Accrued interest receivable	54,800		54,800		27,400
Provision for credit losses	1,550	(4,903)	9,722	(12,534)
Impaired loans more than 90 days past due	11,200		11,200		17,300
Troubled debt restructurings	200		200		200
Specific allowance	$ 2,100		$ 2,100		$ 6,200
Collateralized loan portfolio	97.50%		97.50%		98.50%
Residential Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Mortgage loans held for sale	$ 234,900		$ 234,900		$ 207,700
Unfunded Commitment [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses	4,900	4,200	17,800	3,000
Residential Real Estate [Member] | Asset Pledged as Collateral [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans pledged as collateral	6,300,000		6,300,000		4,900,000
Commercial Real Estate [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Provision for credit losses	5,480	$ (6,582)	8,029	$ (3,259)
Stifel Bancorp [Member] | Executive Officers and Directors [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	69,900		69,900		27,200
Stifel Bancorp [Member] | Executive Officers and Directors of Certain Affiliated Entities [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	$ 69,900		$ 69,900		$ 27,200