Cover - shares	9 Months Ended
	Aug. 31, 2019	Sep. 26, 2019
Cover page.
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Aug. 31, 2019
Document Transition Report	false
Entity File Number	1-5721
Entity Registrant Name	JEFFERIES FINANCIAL GROUP INC.
Entity Incorporation, State or Country Code	NY
Entity Tax Identification Number	13-2615557
Entity Address, Address Line One	520 Madison Avenue
Entity Address, City or Town	New York,
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10022
City Area Code	212
Local Phone Number	460-1900
Title of 12(b) Security	Common Shares, par value $1 per share
Trading Symbol	JEF
Security Exchange Name	NYSE
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		299,871,432
Entity Central Index Key	0000096223
Amendment Flag	false
Current Fiscal Year End Date	--11-30
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q3