Regulatory Capital Requirements (Schedule Of Total Risk-Based, Tier 1 Risk-Based, And Tier 1 Leverage Ratios) (Details) $ in Thousands	Jun. 30, 2017 USD ($)
Stifel Bank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 972,080
Common equity tier 1, Actual Ratio	14.90%
Common equity tier 1, For Capital Adequacy Purposes Amount	$ 392,750
Common equity tier 1, For Capital Adequacy Purposes Ratio	6.00%
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 523,667
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%
Total capital, Actual Amount	$ 1,028,447
Total capital, Actual Ratio	15.70%
Total capital, For Capital Adequacy Purposes Amount	$ 523,667
Total capital, For Capital Adequacy Purposes Ratio	8.00%
Total capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 654,583
Total capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%
Tier 1 leverage, Actual Amount	$ 972,080
Tier 1 leverage, Actual Ratio	7.20%
Tier 1 leverage, For Capital Adequacy Purposes Amount	$ 540,643
Tier 1 leverage, For Capital Adequacy Purposes Ratio	4.00%
Tier 1 leverage, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 675,804
Tier 1 leverage, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	5.00%
Common Stock [Member] | Stifel Bank [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 972,080
Common equity tier 1, Actual Ratio	14.90%
Common equity tier 1, For Capital Adequacy Purposes Amount	$ 294,562
Common equity tier 1, For Capital Adequacy Purposes Ratio	4.50%
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 425,479
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.50%
Stifel Financial Corp. [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Common equity tier 1, Actual Amount	$ 1,889,208
Common equity tier 1, Actual Ratio	20.50%
Common equity tier 1, For Capital Adequacy Purposes Amount	$ 552,824
Common equity tier 1, For Capital Adequacy Purposes Ratio	6.00%
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 737,099
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%
Total capital, Actual Amount	$ 1,943,420
Total capital, Actual Ratio	21.10%
Total capital, For Capital Adequacy Purposes Amount	$ 737,099
Total capital, For Capital Adequacy Purposes Ratio	8.00%
Total capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 921,374
Total capital, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%
Tier 1 leverage, Actual Amount	$ 1,889,208
Tier 1 leverage, Actual Ratio	10.30%
Tier 1 leverage, For Capital Adequacy Purposes Amount	$ 734,557
Tier 1 leverage, For Capital Adequacy Purposes Ratio	4.00%
Tier 1 leverage, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 918,196
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]
Common equity tier 1, Actual Amount	$ 1,679,604
Common equity tier 1, Actual Ratio	18.20%
Common equity tier 1, For Capital Adequacy Purposes Amount	$ 414,618
Common equity tier 1, For Capital Adequacy Purposes Ratio	4.50%
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Amount	$ 598,893
Common equity tier 1, To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	6.50%