Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands		Sep. 30, 2020	Dec. 31, 2019
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities purchased under agreements to resell	[1]	$ 436,860	$ 385,008
Financial instruments owned		819,715	972,932
Available-for-sale securities		2,824,258	3,254,737
Held-to-maturity securities		3,335,033	2,827,883
Derivative contracts			1,086
Securities sold under agreements to repurchase	[2]	182,271	391,634
Financial instruments sold, but not yet purchased, at fair value		599,934	662,852
Senior notes		1,412,005	1,017,010
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,716,570	1,142,596
Cash segregated for regulatory purposes		154,374	131,374
Securities purchased under agreements to resell		436,860	385,008
Financial instruments owned		819,715	972,932
Available-for-sale securities		2,824,258	3,254,737
Held-to-maturity securities		3,397,713	2,856,219
Bank loans		10,650,760	9,624,042
Loans held for sale		281,475	389,693
Investments		108,412	79,972
Derivative contracts	[3]		1,086
Securities sold under agreements to repurchase		182,271	391,634
Bank deposits		16,400,001	15,332,581
Financial instruments sold, but not yet purchased, at fair value		599,934	662,852
Federal Home Loan Bank advances			250,000
Senior notes		1,412,005	1,017,010
Debentures to Stifel Financial Capital Trusts		60,000	60,000
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,716,570	1,142,596
Cash segregated for regulatory purposes		154,374	131,374
Securities purchased under agreements to resell		436,860	385,008
Financial instruments owned		819,715	972,932
Available-for-sale securities		2,824,258	3,254,737
Held-to-maturity securities		3,335,033	2,827,883
Bank loans		10,721,120	9,801,986
Loans held for sale		281,475	389,693
Investments		108,412	79,972
Derivative contracts	[3]		1,086
Securities sold under agreements to repurchase		182,271	391,634
Bank deposits		16,198,251	14,467,894
Financial instruments sold, but not yet purchased, at fair value		599,934	662,852
Federal Home Loan Bank advances			250,000
Senior notes		1,560,013	1,069,425
Debentures to Stifel Financial Capital Trusts		$ 39,338	$ 45,847

[1] Collateral received includes securities received by our company from the counterparty. These securities are not included on the consolidated statements of financial condition unless there is an event of default. The fair value of securities pledged as collateral was $433.6 million and $385.3 million at September 30, 2020 and December 31, 2019, respectively.

[2] Collateral pledged includes the fair value of securities pledged by our company to the counterparty. These securities are included in the consolidated statements of financial condition unless we default. Collateral pledged by our company to the counterparty includes U.S. government agency securities, U.S. government securities, and corporate fixed income securities with market values of $188.5 million and $407.3 million at September 30, 2020 and December 31, 2019, respectively

[3] Included in other assets in the consolidated statements of financial condition.