Regulatory Capital Requirements (Schedule Of Total Risk-Based, Tier 1 Risk-Based, And Tier 1 Leverage Ratios) (Details) $ in Thousands	Mar. 31, 2020 USD ($)
Stifel Financial Corp. [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 2,257,549
Tier 1 capital, Actual Ratio	16.60%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 815,176
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.00%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,086,901
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%
Total capital, Actual Amount	$ 2,406,674
Total capital, Actual Ratio	17.70%
Total capital For Capital Adequacy Purposes, Amount	$ 1,086,901
Total capital For Capital Adequacy Purposes, Ratio	8.00%
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,358,626
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%
Tier 1 leverage, Actual Amount	$ 2,257,549
Tier 1 leverage, Actual Ratio	9.60%
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 941,644
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.00%
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 1,177,055
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%
Stifel Financial Corp. [Member] | Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,947,549
Tier 1 capital, Actual Ratio	14.30%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 611,382
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.50%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 883,107
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%
Stifel Bank & Trust [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,039,680
Tier 1 capital, Actual Ratio	11.70%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 531,225
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.00%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 708,299
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%
Total capital, Actual Amount	$ 1,150,272
Total capital, Actual Ratio	13.00%
Total capital For Capital Adequacy Purposes, Amount	$ 708,299
Total capital For Capital Adequacy Purposes, Ratio	8.00%
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 885,374
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%
Tier 1 leverage, Actual Amount	$ 1,039,680
Tier 1 leverage, Actual Ratio	7.10%
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 583,181
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.00%
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 728,977
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%
Stifel Bank & Trust [Member] | Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 1,039,680
Tier 1 capital, Actual Ratio	11.70%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 398,418
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.50%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 575,493
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%
Stifel Bank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 168,855
Tier 1 capital, Actual Ratio	15.60%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 64,906
Tier 1 capital For Capital Adequacy Purposes, Ratio	6.00%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 86,541
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	8.00%
Total capital, Actual Amount	$ 178,053
Total capital, Actual Ratio	16.50%
Total capital For Capital Adequacy Purposes, Amount	$ 86,541
Total capital For Capital Adequacy Purposes, Ratio	8.00%
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 108,176
Total capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	10.00%
Tier 1 leverage, Actual Amount	$ 168,855
Tier 1 leverage, Actual Ratio	7.30%
Tier 1 leverage For Capital Adequacy Purposes, Amount	$ 92,478
Tier 1 leverage For Capital Adequacy Purposes, Ratio	4.00%
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 115,598
Tier 1 leverage To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	5.00%
Stifel Bank [Member] | Common Stock [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Tier 1 capital, Actual Amount	$ 168,855
Tier 1 capital, Actual Ratio	15.60%
Tier 1 capital For Capital Adequacy Purposes, Amount	$ 48,679
Tier 1 capital For Capital Adequacy Purposes, Ratio	4.50%
Tier 1 capital To Be Well Capitalized Under Prompt Corrective Action Provisions, Amount	$ 70,315
Tier 1 To Be Well Capitalized Under Prompt Corrective Action Provisions, Ratio	6.50%