Goodwill and Other Intangible Assets - Additional Information (Detail)	9 Months Ended
Feb. 28, 2015
Goodwill and Intangible Assets Disclosure [Line Items]
Weighted average number of years of amortization expense	17 years 1 month 6 days

Finite lived intangible assets remaining amortization expense period.

No definition available.

Name:	rell_FiniteLivedIntangibleAssetsRemainingAmortizationExpensePeriod
Namespace Prefix:	rell_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration