Benefit Plans - Additional Information (Details) $ in Thousands, € in Millions		12 Months Ended
		Nov. 30, 2020 USD ($)	Nov. 30, 2019 USD ($)	Nov. 30, 2018 USD ($)	Dec. 28, 2017 USD ($)	Dec. 28, 2017 EUR (€)
Components of net periodic pension cost:
Minimum pension liability adjustments	[1]	$ 2,025	$ 1,318	$ (4,285)
German Plan
Components of net periodic pension cost:
Consideration for release of indemnity relating to pension obligations					$ 3,250
Minimum pension liability adjustments				$ 5,300
Jefferies Bache Limited | German Plan
Components of net periodic pension cost:
Defined benefit pension obligations and insurance contracts transfer amount | €						€ 6.5

[1] The amounts include income tax benefits (expenses) of $0.7 million, $0.5 million and $(0.7) million for the years ended November 30, 2020, 2019 and 2018, respectively. The amount during the year ended November 30, 2020 includes pension net gains of $0.5 million, net of tax of $0.2 million, which were reclassified to Compensation and benefits expenses within the Consolidated Statements of Earnings. The amounts during the years ended November 30, 2019 and 2018 includes pension net gains (losses) of $0.1 million and $(0.3) million, respectively, net of negligible tax benefits (expenses), which were reclassified to Compensation and benefits expenses within the Consolidated Statements of Earnings. The amount during the year ended November 30, 2018 also includes $5.3 million related to the transfer of the German Pension Plan, which was reclassified to Compensation and benefits expenses within the Consolidated Statements of Earnings and $(0.8) million related to the Tax Act, which was reclassified to Member’s paid-in capital.