Regulatory Capital Requirements (Schedule Of Total Risk-Based, Tier 1 Risk-Based, And Tier 1 Leverage Ratios) (Details) $ in Thousands	Sep. 30, 2025 USD ($)	Dec. 31, 2024 USD ($)
Stifel Financial Corp. [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 4,267,042	$ 4,330,786
Tier 1 capital, Actual Ratio	0.176	0.182
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 1,454,128	$ 1,424,494
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.06	0.06
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,938,837	$ 1,899,326
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.08	0.08
Total capital, Actual Amount	$ 4,484,546	$ 4,556,023
Total capital, Actual Ratio	0.185	0.192
Total capital For Capital Adequacy Purposes, Amount	$ 1,938,837	$ 1,899,326
Total capital For Capital Adequacy Purposes, Ratio	0.08	0.08
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 2,423,547	$ 2,374,157
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.10	0.10
Tier 1 leverage, Actual Amount	$ 4,267,042	$ 4,330,786
Tier 1 leverage, Actual Ratio	0.111	0.114
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 1,533,281	$ 1,522,940
Tier 1 leverage For Capital Adequacy Purposes, Ratio	0.04	0.04
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,916,602	$ 1,903,675
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.05	0.05
Stifel Financial Corp. [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 3,582,042	$ 3,645,786
Tier 1 capital, Actual Ratio	0.148	0.154
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 1,090,596	$ 1,068,371
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.045	0.045
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,575,305	$ 1,543,202
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065
Stifel Bank & Trust [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,323,323	$ 1,366,711
Tier 1 capital, Actual Ratio	0.111	0.111
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 716,302	$ 740,084
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.06	0.06
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 955,069	$ 986,778
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.08	0.08
Total capital, Actual Amount	$ 1,436,908	$ 1,491,850
Total capital, Actual Ratio	0.12	0.121
Total capital For Capital Adequacy Purposes, Amount	$ 955,069	$ 986,778
Total capital For Capital Adequacy Purposes, Ratio	0.08	0.08
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,193,837	$ 1,233,473
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.10	0.10
Tier 1 leverage, Actual Amount	$ 1,323,323	$ 1,366,711
Tier 1 leverage, Actual Ratio	0.071	0.071
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 747,814	$ 774,495
Tier 1 leverage For Capital Adequacy Purposes, Ratio	0.04	0.04
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 934,768	$ 968,118
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.05	0.05
Stifel Bank & Trust [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,323,323	$ 1,366,711
Tier 1 capital, Actual Ratio	0.111	0.111
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 537,227	$ 555,063
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.045	0.045
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 775,994	$ 801,758
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065
Stifel Bank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 827,457	$ 768,652
Tier 1 capital, Actual Ratio	0.122	0.13
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 405,678	$ 355,236
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.06	0.06
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 540,904	$ 473,648
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.08	0.08
Total capital, Actual Amount	$ 878,230	$ 812,857
Total capital, Actual Ratio	0.13	0.137
Total capital For Capital Adequacy Purposes, Amount	$ 540,904	$ 473,648
Total capital For Capital Adequacy Purposes, Ratio	0.08	0.08
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 676,130	$ 592,060
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.10	0.10
Tier 1 leverage, Actual Amount	$ 827,457	$ 768,652
Tier 1 leverage, Actual Ratio	0.071	0.071
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 464,632	$ 433,925
Tier 1 leverage For Capital Adequacy Purposes, Ratio	0.04	0.04
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 580,791	$ 542,407
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.05	0.05
Stifel Bank [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 827,457	$ 768,652
Tier 1 capital, Actual Ratio	0.122	0.13
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 304,259	$ 266,427
Tier 1 capital For Capital Adequacy Purposes, Ratio	0.045	0.045
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 439,485	$ 384,839
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	0.065	0.065

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Amount of minimum total risk-based capital required for capital adequacy as defined by regulatory framework.

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Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
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-Section 50
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-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1B

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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477270/942-505-50-1

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