Short-Term Borrowings (Details) (USD $)	12 Months Ended
	Dec. 31, 2013	Dec. 31, 2012	Dec. 31, 2011	Sep. 30, 2013
Daily borrowings under credit arrangements	$ 561,200,000
Uncommitted secured lines of credit	680,000,000
Committed revolving credit facility	100,000,000
Interest rate percentage over one-month Eurocurrency rate	1.00%
Short-term borrowings from banks	55,700,000	304,700,000
Company-owned securities collateralized value		607,586,000		686,997,000
Weighted average daily interest rates	1.22%	1.14%
Debt instrument interest rate during period	1.26%	1.10%	1.15%
Average outstanding securities	252,900,000	184,400,000	199,600,000
Stock loan balance	40,101,000	19,218,000
Stifel Nicolaus [Member]
Short-term borrowings from banks	55,700,000
Debt instrument interest rate during period	0.17%	0.16%
Average outstanding securities	91,200,000	137.30	124,100,000
Company Owned Securities [Member]
Company-owned securities collateralized value	440,800,000	530,700,000
Stock Loan Balance [Member] | Stifel Nicolaus [Member]
Weighted average daily interest rates	0.16%	0.24%
Stock loan balance	$ 40,100,000	$ 19,200,000