Document and Entity Information - shares	6 Months Ended
	May 31, 2019	Jul. 02, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Document Period End Date	May 31, 2019
Entity Registrant Name	JEFFERIES FINANCIAL GROUP INC.
Entity Central Index Key	0000096223
Amendment Flag	false
Current Fiscal Year End Date	--11-30
Entity Filer Category	Large Accelerated Filer
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		300,002,794