Regulatory Capital Requirements (Narrative) (Details) $ in Millions	Mar. 31, 2021 USD ($)
Our Other Broker-Dealer Subsidiaries
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Ratio of indebtedness to net capital	15
Stifel Nicolaus [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Aggregate debit balances	39.80%
Net capital	$ 570.3
Excess of minimum required net capital	541.6
Stifel Financial Corp. [Member]
Compliance With Regulatory Capital Requirements Under Banking Regulations [Line Items]
Net capital under the alternative method	$ 1.0
Aggregate debit balances	2.00%

Percentage of aggregate debit balances.

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- Definition

Amount of net capital in excess of minimum required net capital, calculated under Alternative Standard.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

+ Details

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- Definition

Minimum amount of net capital of broker-dealer and its subsidiary, calculated under Alternative Standard.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

+ Details

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- Definition

Amount of net capital of broker-dealer.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

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Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

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- Definition

Indebtedness divided by net capital.

+ References

No definition available.

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