Investments - Jefferies Finance - Narrative (Details) - Jefferies Finance, LLC $ in Millions	6 Months Ended
	May 31, 2021 USD ($) businessLine	Nov. 30, 2020 USD ($)
Guarantee Obligations [Line Items]
Number of business lines | businessLine	2
Equity commitment	$ 750.0
Total committed equity capitalization of JFIN	1,500.0
Funded portion of equity commitment to subsidiary	676.8
Unfunded portion of equity commitment to subsidiary	$ 73.2
Extension period	1 year
Termination notice period	60 days
Funded portion of loan commitment	$ 0.0
Loan commitment	250.0
Jefferies Credit Partners
Guarantee Obligations [Line Items]
Amount managed under private credit platform	10,000.0
Minimum | Leveraged Finance Arrangement
Guarantee Obligations [Line Items]
Transaction range	250.0
Maximum | Leveraged Finance Arrangement
Guarantee Obligations [Line Items]
Transaction range	1,500.0
Other assets
Guarantee Obligations [Line Items]
Receivables under service agreement	31.6	$ 24.2
Accrued expense and other liabilities
Guarantee Obligations [Line Items]
Due to related parties	1.8	$ 13.7
Corporate debt securities
Guarantee Obligations [Line Items]
Committed line of credit facility amount	$ 500.0