Net Capital Requirements (Details) - Jefferies LLC $ in Millions	Aug. 31, 2020 USD ($)
Net Capital Requirements [Line Items]
Net capital	$ 1,612.5
Excess net capital	$ 1,531.9

Amount of net capital in excess of minimum required net capital, calculated under Alternative Standard.

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Publisher SEC
-Name Rule 15c3-1
-Number 240
-Section 15c3-1

Name:	srt_AlternativeExcessNetCapital
Namespace Prefix:	srt_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant