Long-Term Debt (Schedule of Debt) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Aug. 31, 2020	Aug. 31, 2019	Aug. 31, 2020	Aug. 31, 2019	Nov. 30, 2019
Debt Instrument [Line Items]
Long-term debt	$ 8,419,837		$ 8,419,837		$ 8,337,061
Losses associated with an interest rate swap based on its designation as a fair value hedge	(2,468)	$ 467	(1,764)	$ 2,445
Parent Company
Debt Instrument [Line Items]
Long-term debt	992,372		992,372		991,378
Parent Company | 5.50% Senior Notes due October 18, 2023
Debt Instrument [Line Items]
Long-term debt	$ 745,558		$ 745,558		$ 744,606
Interest rate	5.50%		5.50%		5.50%
Principal outstanding	$ 750,000		$ 750,000		$ 750,000
Parent Company | 6.625% Senior Notes due October 23, 2043
Debt Instrument [Line Items]
Long-term debt	$ 246,814		$ 246,814		$ 246,772
Interest rate	6.625%		6.625%		6.625%
Principal outstanding	$ 250,000		$ 250,000		$ 250,000
Subsidiaries
Debt Instrument [Line Items]
Long-term debt	7,427,465		7,427,465		7,345,683
Subsidiaries | 2.375% Euro Medium Term Notes, due May 20, 2020
Debt Instrument [Line Items]
Long-term debt	0		0		$ 550,622
Interest rate					2.375%
Principal outstanding	0		0		$ 550,875
Subsidiaries | 6.875% Senior Notes, due April 15, 2021
Debt Instrument [Line Items]
Long-term debt	$ 761,430		$ 761,430		$ 774,738
Interest rate	6.875%		6.875%		6.875%
Principal outstanding	$ 750,000		$ 750,000		$ 750,000
Subsidiaries | 2.25% Euro Medium Term Notes, due July 13, 2022
Debt Instrument [Line Items]
Long-term debt	$ 4,613		$ 4,613		$ 4,204
Interest rate	2.25%		2.25%		2.25%
Principal outstanding	$ 4,774		$ 4,774		$ 4,407
Subsidiaries | 5.125% Senior Notes, due January 20, 2023
Debt Instrument [Line Items]
Long-term debt	$ 760,999		$ 760,999		$ 610,023
Interest rate	5.125%		5.125%		5.125%
Principal outstanding	$ 750,000		$ 750,000		$ 600,000
Subsidiaries | 1.00% Euro Medium Term Notes, due July 19, 2024
Debt Instrument [Line Items]
Long-term debt	$ 594,965		$ 594,965		$ 548,880
Interest rate	1.00%		1.00%		1.00%
Principal outstanding	$ 596,725		$ 596,725		$ 550,875
Subsidiaries | 4.85% Senior Notes, due January 15, 2027
Debt Instrument [Line Items]
Long-term debt	$ 814,873		$ 814,873		$ 768,931
Interest rate	4.85%		4.85%		4.85%
Principal outstanding	$ 750,000		$ 750,000		$ 750,000
Subsidiaries | 6.45% Senior Debentures, due June 8, 2027
Debt Instrument [Line Items]
Long-term debt	$ 369,662		$ 369,662		$ 371,426
Interest rate	6.45%		6.45%		6.45%
Principal outstanding	$ 350,000		$ 350,000		$ 350,000
Subsidiaries | 4.15% Senior Notes, due January 23, 2030
Debt Instrument [Line Items]
Long-term debt	$ 989,342		$ 989,342		$ 988,662
Interest rate	4.15%		4.15%		4.15%
Principal outstanding	$ 1,000,000		$ 1,000,000		$ 1,000,000
Subsidiaries | 6.25% Senior Debentures, due January 15, 2036
Debt Instrument [Line Items]
Long-term debt	$ 510,943		$ 510,943		$ 511,260
Interest rate	6.25%		6.25%		6.25%
Principal outstanding	$ 500,000		$ 500,000		$ 500,000
Subsidiaries | 6.50% Senior Notes, due January 20, 2043
Debt Instrument [Line Items]
Long-term debt	$ 419,931		$ 419,931		$ 420,239
Interest rate	6.50%		6.50%		6.50%
Principal outstanding	$ 400,000		$ 400,000		$ 400,000
Subsidiaries | Structured Notes
Debt Instrument [Line Items]
Long-term debt	1,522,105		1,522,105		1,215,285
Subsidiaries | HomeFed EB-5 Program debt
Debt Instrument [Line Items]
Long-term debt	189,335		189,335		140,739
Subsidiaries | HomeFed construction loan
Debt Instrument [Line Items]
Long-term debt	45,638		45,638		0
Subsidiaries | Foursight Capital Credit Facilities
Debt Instrument [Line Items]
Long-term debt	99,802		99,802		98,260
Subsidiaries | Vitesse Energy Finance Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	104,256		104,256		103,050
Subsidiaries | Other
Debt Instrument [Line Items]
Long-term debt	0		0		276
Subsidiaries | Jefferies Group | Jefferies Group Revolving Credit Facility
Debt Instrument [Line Items]
Long-term debt	189,571		189,571		189,088
Subsidiaries | Jefferies Group | Jefferies Group Secured Bank Loan
Debt Instrument [Line Items]
Long-term debt	$ 50,000		50,000		$ 50,000
Subsidiaries | Interest rate swaps | 4.85% Senior Notes, due January 15, 2027
Debt Instrument [Line Items]
Losses associated with an interest rate swap based on its designation as a fair value hedge			$ 45,500	$ 72,300