Commitments, Contingencies and Guarantees - Narrative (Details) $ in Millions	12 Months Ended
	Nov. 30, 2024 USD ($)
Loss Contingencies [Line Items]
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	$ (324.6)
HomeFed LLC
Loss Contingencies [Line Items]
Aggregate amount of infrastructure improvement bonds, outstanding	46.9
Standby letters of credit
Loss Contingencies [Line Items]
Letters of credit commitments	$ 301.2
Standby letters of credit | Maximum
Loss Contingencies [Line Items]
Letters of credit commitments expiration period	1 year
Outstanding loan commitments to clients
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	$ 88.4
Outstanding loan commitments to strategic affiliates
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	9.6
Jefferies Capital Partners LLC
Loss Contingencies [Line Items]
Outstanding equity commitments	9.8
Strategic Affiliates
Loss Contingencies [Line Items]
Outstanding equity commitments	250.7
Other Investments
Loss Contingencies [Line Items]
Outstanding equity commitments	$ 43.0