Commitments, Contingencies and Guarantees - Narrative (Details) $ in Millions	9 Months Ended
Aug. 31, 2026 USD ($)
Loss Contingencies [Line Items]
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	$ (759.2)
Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit commitments	$ 455.6
Standby Letters of Credit \| Maximum
Loss Contingencies [Line Items]
Letters of credit commitments expiration period	1 year
HomeFed LLC
Loss Contingencies [Line Items]
Aggregate amount of infrastructure improvement bonds, outstanding	$ 68.3
Outstanding Loan Commitments to Clients
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	220.3
Outstanding Loan Commitments to Strategic Affiliates
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	3.2
Jefferies Capital Partners LLC
Loss Contingencies [Line Items]
Outstanding equity commitments	9.7
Strategic Affiliates
Loss Contingencies [Line Items]
Outstanding equity commitments	163.8
Other Investments
Loss Contingencies [Line Items]
Outstanding equity commitments	$ 114.4

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.

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