Commitments, Contingencies and Guarantees - Narrative (Details) $ in Millions	3 Months Ended
	Feb. 28, 2025 USD ($)
Loss Contingencies [Line Items]
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	$ (299.9)
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
HomeFed LLC
Loss Contingencies [Line Items]
Aggregate amount of infrastructure improvement bonds, outstanding	$ 63.3
Outstanding Loan Commitments to Clients
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	84.9
Outstanding Loan Commitments to Strategic Affiliates
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	2.2
Jefferies Capital Partners LLC
Loss Contingencies [Line Items]
Outstanding equity commitments	9.8
Strategic Affiliates
Loss Contingencies [Line Items]
Outstanding equity commitments	153.7
Other Investments
Loss Contingencies [Line Items]
Outstanding equity commitments	$ 42.0