Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands		Sep. 30, 2024		Jul. 18, 2024	Dec. 31, 2023
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities purchased under agreements to resell		$ 665,067			$ 349,849
Financial instruments owned		1,351,298			918,741
Available-for-sale securities, Fair Value		1,618,289	[1]		1,551,686
Held-to-maturity securities	[2]	6,626,453			5,852,176
Derivative contracts, Assets		95,327	[3]		118,668	[4]
Securities sold under agreements to repurchase		657,984			417,644
Financial instruments sold, but not yet purchased, at fair value		768,909			497,741
Senior notes		616,412		$ 500,000	1,115,629
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,915,767			3,361,801
Cash segregated for regulatory purposes		29,519			162,048
Securities purchased under agreements to resell		665,067			349,849
Financial instruments owned		1,351,298			918,741
Available-for-sale securities, Fair Value		1,618,289			1,551,686
Held-to-maturity securities		6,613,793			5,888,798
Bank loans		20,167,686			19,305,805
Loans held for sale		465,739			423,999
Investments		93,050			91,105
Derivative contracts, Assets	[5]	95,327			118,668
Securities sold under agreements to repurchase		657,984			417,644
Bank deposits		28,120,518			27,334,579
Financial instruments sold, but not yet purchased, at fair value		768,909			497,741
Senior notes		616,412			1,115,629
Debentures to Stifel Financial Capital Trusts		60,000			60,000
Derivative contracts	[6]	95,314			118,651
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,915,767			3,361,801
Cash segregated for regulatory purposes		29,519			162,048
Securities purchased under agreements to resell		665,067			349,849
Financial instruments owned		1,351,298			918,741
Available-for-sale securities, Fair Value		1,618,289			1,551,686
Held-to-maturity securities		6,626,453			5,852,176
Bank loans		19,447,489			18,259,923
Loans held for sale		465,739			423,999
Investments		93,050			91,105
Derivative contracts, Assets	[5]	95,327			118,668
Securities sold under agreements to repurchase		657,984			417,644
Bank deposits		26,182,382			25,326,174
Financial instruments sold, but not yet purchased, at fair value		768,909			497,741
Senior notes		592,839			1,041,217
Debentures to Stifel Financial Capital Trusts		55,508			55,507
Derivative contracts	[6]	$ 95,314			$ 118,651

[1] Due to the immaterial amount of income recognized on tax-exempt securities, yields were not calculated on a tax-equivalent basis.

[2] Held-to-maturity securities are carried in the consolidated statements of financial condition at amortized cost, and the changes in the value of these securities, other than impairment charges, are not reported on the consolidated financial statements.

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

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

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

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