Income Taxes - Schedule of Income Before Income Tax, Domestic and Foreign (Details) - USD ($) $ in Thousands	12 Months Ended
Jun. 01, 2019	Jun. 02, 2018	May 27, 2017
Components Of Income Loss Before Income Taxes [Abstract]
Loss from Continuing Operations before Income Taxes, United States	$ (9,971)	$ (211)	$ (8,150)
Income from Continuing Operations before Income Taxes, Foreign	3,660	4,071	2,034
(Loss) income from continuing operations before income taxes	$ (6,311)	$ 3,860	$ (6,116)

Components of income (loss) before income taxes.

No definition available.

Name:	rell_ComponentsOfIncomeLossBeforeIncomeTaxesAbstract
Namespace Prefix:	rell_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to domestic operations.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(h)(1)(i))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The portion of earnings or loss from continuing operations before income taxes that is attributable to foreign operations, which is defined as Income or Loss generated from operations located outside the entity's country of domicile.

+ References

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of income (loss) from continuing operations before deduction of income tax expense (benefit) and income (loss) attributable to noncontrolling interest, and addition of income (loss) from equity method investments.

+ References

+ Details

Name:	us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration