Regulatory Capital Requirements (Schedule Of Total Risk-Based, Tier 1 Risk-Based, And Tier 1 Leverage Ratios) (Details) $ in Thousands	Sep. 30, 2021 USD ($)
Stifel Financial Corp. [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 3,501,734
Tier 1 capital, Actual Ratio	0.206
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 1,019,591
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.0
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,359,454
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.0
Total capital, Actual Amount	$ 3,643,378
Total capital, Actual Ratio	0.214
Total capital For Capital Adequacy Purposes, Amount	$ 1,359,454
Total capital For Capital Adequacy Purposes, Ratio	8.0
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,699,318
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.0
Tier 1 leverage, Actual Amount	$ 3,501,734
Tier 1 leverage, Actual Ratio	0.120
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 1,164,911
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.0
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,456,139
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.0
Stifel Financial Corp. [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 2,816,734
Tier 1 capital, Actual Ratio	0.166
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 764,693
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.5
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,104,557
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.5
Stifel Bank & Trust [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,145,805
Tier 1 capital, Actual Ratio	0.107
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 643,629
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.0
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 858,172
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.0
Total capital, Actual Amount	$ 1,250,328
Total capital, Actual Ratio	0.117
Total capital For Capital Adequacy Purposes, Amount	$ 858,172
Total capital For Capital Adequacy Purposes, Ratio	8.0
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,072,715
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.0
Tier 1 leverage, Actual Amount	$ 1,145,805
Tier 1 leverage, Actual Ratio	0.070
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 651,241
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.0
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 814,051
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.0
Stifel Bank & Trust [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,145,805
Tier 1 capital, Actual Ratio	0.107
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 482,722
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.5
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 697,264
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.5
Stifel Bank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 309,150
Tier 1 capital, Actual Ratio	0.209
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 88,843
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.0
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 118,457
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.0
Total capital, Actual Amount	$ 316,431
Total capital, Actual Ratio	0.214
Total capital For Capital Adequacy Purposes, Amount	$ 118,457
Total capital For Capital Adequacy Purposes, Ratio	8.0
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 148,071
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.0
Tier 1 leverage, Actual Amount	$ 309,150
Tier 1 leverage, Actual Ratio	0.071
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 174,525
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.0
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 218,157
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.0
Stifel Bank [Member] \| Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 309,150
Tier 1 capital, Actual Ratio	0.209
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 66,632
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.5
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 96,246
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.5

Amount of total capital as defined by regulatory framework.

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

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
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-Section 50
-Paragraph 1B
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Ratio of minimum total risk-based capital to risk-weighted assets required for capital adequacy as defined by regulatory framework.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1B
-URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958570-112826

Reference 2: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 505
-Section 50
-Paragraph 1
-Subparagraph (c)(1)
-URI http://asc.fasb.org/extlink&oid=117337116&loc=SL5958568-112826

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Amount of minimum total risk-based capital categorized as well capitalized as defined by regulatory framework for prompt corrective action.

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Ratio of total risk-based capital to risk-weighted assets as defined by regulatory framework.

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Amount of Tier 1 leverage capital as defined by regulatory framework.

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Amount of minimum Tier 1 leverage capital required for capital adequacy as defined by regulatory framework.

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