Restructuring Costs (Narrative) (Details) - store	3 Months Ended	9 Months Ended
Feb. 27, 2021	May 29, 2021
Restructuring Costs [Abstract]
Number of locations closed	73	73

Restructuring and Related Cost, Number of locations closed

No definition available.

Name:	msm_RestructuringAndRelatedCostNumberOfLocationsClosed
Namespace Prefix:	msm_
Data Type:	xbrli:positiveIntegerItemType
Balance Type:	na
Period Type:	duration