Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Instruments) (Details) (USD $) In Thousands, unless otherwise specified	9 Months Ended	12 Months Ended
	Sep. 30, 2013	Dec. 31, 2012
Cash and cash equivalents	$ 138,833	$ 72,596
Securities purchased under agreements to resell	168,182	158,695
Trading securities owned, at fair value	847,652	763,608
Available-for-sale Securities	1,231,571	1,625,168
Held-to-maturity securities, Estimated fair value	1,732,534	715,274	[1]
Investments	233,778	236,434
Securities purchased under agreements to repurchase	255,451	140,346
Bank deposits	4,228,405	3,346,133
Trading securities sold, but not yet purchased, at fair value	495,658	319,742
Derivative contracts	11,101	19,934
Carrying Value [Member]
Cash and cash equivalents	649,244	403,941
Restricted cash	4,419	4,414
Cash segregated for regulatory purposes	33	128,031
Securities purchased under agreements to resell	168,182	158,695
Trading securities owned, at fair value	847,652	763,608
Available-for-sale Securities	1,231,571	1,625,168
Held-to-maturity securities, Estimated fair value	1,723,482	708,008
Loans held for sale	75,440	214,531
Bank loans	1,061,150	815,937
Investments	233,778	236,434
Securities purchased under agreements to repurchase	255,451	140,346
Bank deposits	4,228,405	3,346,133
Trading securities sold, but not yet purchased, at fair value	495,658	319,742
Securities sold, but not yet purchased	28,598	22,966
Derivative contracts	11,101	19,934
Senior notes	325,000	325,000
Non-Recourse Debt	32,111	58,992
Debentures to Stifel Financial Capital Trusts	82,500	82,500
Liabilities subordinated to the claims of general creditors	3,131	5,318
Estimated Fair Value [Member]
Cash and cash equivalents	649,244	403,941
Restricted cash	4,419	4,414
Cash segregated for regulatory purposes	33	128,031
Securities purchased under agreements to resell	168,182	158,695
Trading securities owned, at fair value	847,652	763,608
Available-for-sale Securities	1,231,571	1,625,168
Held-to-maturity securities, Estimated fair value	1,732,534	715,274
Loans held for sale	75,440	214,531
Bank loans	1,076,079	834,188
Investments	233,778	236,434
Securities purchased under agreements to repurchase	255,451	140,346
Bank deposits	3,659,589	3,368,643
Trading securities sold, but not yet purchased, at fair value	495,658	319,742
Securities sold, but not yet purchased	28,598	22,966
Derivative contracts	11,101	19,934
Senior notes	335,986	338,475
Non-Recourse Debt	32,541	58,992
Debentures to Stifel Financial Capital Trusts	74,313	66,545
Liabilities subordinated to the claims of general creditors	$ 3,097	$ 5,204

[1] Held-to-maturity securities are carried at historical cost or at fair value at the time of transfer from the available-for-sale to held-to-maturity category, adjusted for amortization of premiums and accretion of discounts and credit-related other-than-temporary impairment.