Bank Loans (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016	Dec. 31, 2016
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans held for sale, at lower of cost or market	$ 166,335		$ 166,335		$ 228,588
Gains (losses) recognized from sale of loans	3,200	$ 4,900	9,400	$ 11,700
Impaired loans more than 90 days past due	15,000		15,000		26,900
Troubled debt restructurings	8,900		8,900		9,700
Specific allowance	$ 2,307		$ 2,307		$ 3,375
Collateralized loan portfolio	96.80%		96.80%		97.90%
Stifel Financial Corp. [Member] | Executive Officers Directors and Their Affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	$ 7,200		$ 7,200		$ 5,600
Stifel Bank [Member] | Executive Officers Directors and Their Affiliates [Member]
Accounts, Notes, Loans and Financing Receivable [Line Items]
Loans outstanding amount	$ 3,700		$ 3,700		$ 3,700