Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2020	May 31, 2019	May 31, 2020	May 31, 2019	Nov. 30, 2019
Income Taxes [Line Items]
Unrecognized tax benefits	$ 364,300		$ 364,300		$ 327,300
Interest included in unrecognized tax benefits	78,400		78,400		67,200
Net deferred tax asset	392,600		392,600		462,500
Income tax provision (benefit)	31,962	$ (488,797)	$ 77,735	$ (486,495)
Effective income tax rate			33.30%
Recognition of accumulated other comprehensive income lodged taxes		544,600	$ 0	544,583
Lodged tax effect		$ 544,600		$ 544,600
Jefferies Group
Income Taxes [Line Items]
Unrecognized tax benefits	$ 217,800		$ 217,800		$ 181,200