Commitments, Contingencies and Guarantees - Additional Information (Details) $ in Millions	9 Months Ended
	Aug. 31, 2020 USD ($)
Loss Contingencies [Line Items]
Loan commitments outstanding to clients	$ 80.0
Fair value of derivative contracts approximated deemed to meet the definition of a guarantee	197.9
Standby Letters of Credit
Loss Contingencies [Line Items]
Letters of credit commitments	$ 20.4
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	$ 11.2
Other Investments
Loss Contingencies [Line Items]
Outstanding equity commitments	$ 6.7