Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	May 31, 2019	Jun. 30, 2018	May 31, 2019	Jun. 30, 2018	Feb. 28, 2019	Nov. 30, 2018
Income Taxes [Line Items]
Unrecognized tax benefits	$ 260,000		$ 260,000			$ 251,400
Interest included in unrecognized tax benefits	61,600		61,600			54,100
Benefit for income taxes	488,797	$ (9,598)	486,495	$ 38,831
Recognition of accumulated other comprehensive income lodged taxes	544,600		544,583	0
Lodged tax effect					$ 544,600
Tax Cuts and Jobs Act of 2017, measurement period adjustment, income tax benefit			6,700
Decrease of income tax provision				$ 43,900
Jefferies Group
Income Taxes [Line Items]
Unrecognized tax benefits	$ 189,200		$ 189,200			$ 174,900