Commitments, Guarantees, And Contingencies (Narrative) (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013
CommitmentsOutstandingtoBusinessDevelopmentCorporations	$ 21.3
CommitmentsOutstanding	33.1
Customer-owned securities pledged	246.2	263.8
Minimum margin deposit requirements	28.7
Auction rate securities, at par, held by retail clients after issuer redemptions and Stifel repurchases	18.3
Auction rate securities, repurchase period	2 years
Options Clearing Corporation [Member]
Customer-owned securities pledged	52.2
National Securities Clearing Corporation [Member]
Minimum margin deposit requirements	26.7
Minimum [Member]
Minimum margin deposit requirements	$ 39.5