Fair Value Of Financial Instruments (Schedule Of Fair Value Of Financial Instruments) (Details) - USD ($) $ in Thousands		Sep. 30, 2018	Dec. 31, 2017
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Securities purchased under agreements to resell	[1]	$ 622,361	$ 512,220
Financial instruments owned		1,162,732	1,143,684
Available-for-sale securities		3,349,607	3,773,508
Held-to-maturity securities	[2]	4,506,385	3,710,478
Investments, at fair value		79,170	111,379
Derivative contracts		11,117	7,995
Securities sold under agreements to repurchase	[3]	495,484	233,704
Bank deposits		14,502,952	13,411,935
Financial instruments sold, but not yet purchased, at fair value		911,374	778,863
Borrowings		140,030	256,000
Carrying Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		694,302	696,283
Cash segregated for regulatory purposes		21,585	90,802
Securities purchased under agreements to resell		622,361	512,220
Financial instruments owned		1,162,732	1,143,684
Available-for-sale securities		3,349,607	3,773,508
Held-to-maturity securities		4,565,453	3,698,098
Loans held for sale		262,063	226,068
Bank loans		8,253,989	6,947,759
Investments, at fair value		79,170	111,379
Derivative contracts	[4]	11,117	7,995
Securities sold under agreements to repurchase		495,484	233,704
Bank deposits		14,502,952	13,411,935
Financial instruments sold, but not yet purchased, at fair value		911,374	778,863
Federal Home Loan Bank advances		1,064,000	745,000
Borrowings		140,030	256,000
Senior notes		1,015,714	1,014,940
Debentures to Stifel Financial Capital Trusts		67,500	67,500
Estimated Fair Value [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Cash and cash equivalents		694,302	696,283
Cash segregated for regulatory purposes		21,585	90,802
Securities purchased under agreements to resell		622,361	512,220
Financial instruments owned		1,162,732	1,143,684
Available-for-sale securities		3,349,607	3,773,508
Held-to-maturity securities		4,506,385	3,710,478
Loans held for sale		262,063	226,068
Bank loans		8,330,974	6,953,328
Investments, at fair value		79,170	111,379
Derivative contracts	[4]	11,117	7,995
Securities sold under agreements to repurchase		495,484	233,704
Bank deposits		13,711,447	12,702,746
Financial instruments sold, but not yet purchased, at fair value		911,374	778,863
Federal Home Loan Bank advances		1,064,000	745,000
Borrowings		140,030	256,000
Senior notes		1,012,374	1,044,768
Debentures to Stifel Financial Capital Trusts		$ 68,839	$ 64,962

[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 $621.5 million and $509.4 million at September 30, 2018 and December 31, 2017, respectively.

[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] Collateral pledged includes the fair value of securities pledged by our company to the counter party. These securities are included on the consolidated statements of financial condition unless we default. Collateral pledged by our company to the counter party includes U.S. government agency securities, U.S. government securities, and corporate fixed income securities with market values of $522.4 million and $241.4 million at September 30, 2018 and December 31, 2017, respectively.

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