XML 54 R43.htm IDEA: XBRL DOCUMENT
v3.7.0.1

Asset Retirement Obligations - Narrative (Details) | 9 Months Ended
--- | ---
May 27, 2017
Minimum |
Asset Retirement Obligations [Line Items] |
Remaining lives | 1 year
Maximum |
Asset Retirement Obligations [Line Items] |
Remaining lives | 27 years

X
- Definition This element describes the minimum years the Company will discount the liability of estimated future costs to decommission one of its facilities. + References No definition available. + Details
Name: | unf_AssetRetirementObligationRemainingLives
Namespace Prefix: | unf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition [Line Items] for Asset Retirement Obligations [Table] + References No definition available. + Details
Name: | unf_AssetRetirementObligationsLineItems
Namespace Prefix: | unf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |