Note 9 - Asset Retirement Obligations (Details Textual)	3 Months Ended
Nov. 28, 2015
Maximum [Member]
Asset Retirement Obligation, Remaining Lives	28 years
Minimum [Member]
Asset Retirement Obligation, Remaining Lives	5 years

This element describes the minimum years the Company will discount the liability of estimated future costs to decommission one of its facilities.

No definition available.

Name:	unf_AssetRetirementObligationRemainingLives
Namespace Prefix:	unf_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration