Commitments, Contingencies and Guarantees - Additional Information (Details) $ in Millions	6 Months Ended
	May 31, 2021 USD ($)
Loss Contingencies [Line Items]
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	$ 173.7
Outstanding loan commitments to clients
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	104.0
Standby letters of credit
Loss Contingencies [Line Items]
Letters of credit commitments	$ 7.0
Standby letters of credit | Maximum
Loss Contingencies [Line Items]
Standby letters of credit expiration period	1 year
Jefferies Capital Partners LLC
Loss Contingencies [Line Items]
Outstanding equity commitments	$ 10.8
Other investments
Loss Contingencies [Line Items]
Outstanding equity commitments	33.1
Strategic affiliates
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	$ 1.0