Fair Value Of Financial Instruments (Schedule of Fair Value of Financial Instruments) (Details) - USD ($) $ in Thousands		Jun. 30, 2025	Dec. 31, 2024
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities purchased under agreements to resell		$ 637,530	$ 528,976
Financial instruments owned		1,343,513	1,169,008
Available-for-sale securities		1,546,392	1,584,598
Held-to-maturity securities	[1]	6,602,463	6,547,647
Securities sold under agreements to repurchase		719,432	580,170
Financial instruments sold, but not yet purchased, at fair value		819,555	646,271
Senior notes		617,030	616,618
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,857,669	2,648,308
Cash segregated for regulatory purposes		68,394	29,895
Securities purchased under agreements to resell		637,530	528,976
Financial instruments owned		1,343,513	1,169,008
Available-for-sale securities		1,546,392	1,584,598
Held-to-maturity securities		6,584,925	6,524,954
Bank loans		20,647,094	20,731,796
Loans held for sale		800,766	578,980
Investments		78,572	75,358
Derivative contracts, Assets	[2]	82,353	110,825
Securities sold under agreements to repurchase		719,432	580,170
Bank deposits		28,673,063	29,102,227
Financial instruments sold, but not yet purchased, at fair value		819,555	646,271
Senior notes		617,030	616,618
Debentures to Stifel Financial Capital Trusts		60,000	60,000
Derivative contracts	[3]	82,341	110,814
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		1,857,669	2,648,308
Cash segregated for regulatory purposes		68,394	29,895
Securities purchased under agreements to resell		637,530	528,976
Financial instruments owned		1,343,513	1,169,008
Available-for-sale securities		1,546,392	1,584,598
Held-to-maturity securities		6,602,463	6,547,647
Bank loans		20,168,196	20,229,458
Loans held for sale		800,766	578,980
Investments		78,572	75,358
Derivative contracts, Assets	[2]	82,353	110,825
Securities sold under agreements to repurchase		719,432	580,170
Bank deposits		26,896,637	27,164,580
Financial instruments sold, but not yet purchased, at fair value		819,555	646,271
Senior notes		579,961	561,851
Debentures to Stifel Financial Capital Trusts		55,973	58,788
Derivative contracts	[3]	$ 82,341	$ 110,814

[1] 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.

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

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