Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2012		Dec. 31, 2011
Cash and cash equivalents	$ 48,751		$ 14,156
Securities purchased under agreements to resell	103,958		75,455
Trading Securities, Fair Value Disclosure	575,724		474,951
Available-for-sale securities, at fair value	1,347,535		1,214,141
Investments	244,106		239,208
Securities sold under agreements to repurchase	142,119		80,176
Bank deposits	2,357,912		2,071,738
Trading securities sold, but not yet purchased	267,807		266,833
Carrying Value [Member]
Cash and cash equivalents	226,458		167,671
Restricted cash	6,584		6,883
Cash segregated for regulatory purposes	26		26
Securities purchased under agreements to resell	103,958		75,455
Trading Securities, Fair Value Disclosure	575,724		474,951
Available-for-sale securities, at fair value	1,347,535		1,214,141
Held-to-maturity securities	327,447		190,484
Loans held for sale	141,136		131,754
Bank loans	657,193		632,140
Investments	244,106		239,208
Securities sold under agreements to repurchase	142,119		80,176
Bank deposits	2,357,912		2,071,738
Trading securities sold, but not yet purchased	267,807		266,833
Securities sold, but not yet purchased	21,823		19,223
Derivative contracts	21,040	[1]	24,877	[1]
Senior notes	175,000
Debentures to Stifel Financial Capital Trusts	82,500		82,500
Liabilities subordinated to the claims of general creditors	5,318		6,957
Estimated Fair Value [Member]
Cash and cash equivalents	226,458		167,671
Restricted cash	6,584		6,883
Cash segregated for regulatory purposes	26		26
Securities purchased under agreements to resell	103,958		75,455
Trading Securities, Fair Value Disclosure	575,724		474,951
Available-for-sale securities, at fair value	1,347,535		1,214,141
Held-to-maturity securities	329,833		189,071
Loans held for sale	141,136		131,754
Bank loans	665,773		639,341
Investments	244,106		239,208
Securities sold under agreements to repurchase	142,119		80,176
Bank deposits	2,326,411		2,067,324
Trading securities sold, but not yet purchased	267,807		266,833
Securities sold, but not yet purchased	21,823		19,223
Derivative contracts	21,040	[1]	24,877	[1]
Senior notes	189,108
Debentures to Stifel Financial Capital Trusts	69,206		67,594
Liabilities subordinated to the claims of general creditors	$ 5,079		$ 6,671

[1] Included in accounts payable and accrued expenses in the consolidated statements of financial condition.