XML 50 R37.htm IDEA: XBRL DOCUMENT
v3.22.2.2

Summary of Significant Accounting Policies - Narrative (Details) | 12 Months Ended
--- | ---
Aug. 27, 2022 USD ($) Segment shares | Aug. 28, 2021 USD ($) shares | Aug. 29, 2020 USD ($) shares
Summary of Significant Accounting Policies [Line Items] |  |  |
Number of reporting segments | Segment | 5 |  |
Short-term investments | $ 0 | $ 0 |
Percentage of revenues derived from route servicing fees | 88.50% |  |
Current assets related to deferred commissions | $ 15,200,000 | 14,200,000 |
Noncurrent assets related to deferred commissions | 65,100,000 | 60,600,000 |
Amortization expense related to deferred commissions | $ 15,400,000 | 14,400,000 |
Estimated service lives of rental merchandise, minimum | 6 months |  |
Estimated service lives of rental merchandise, maximum | 36 months |  |
Impairment of goodwill and definite-lived intangible assets | $ 0 | 0 | $ 0
Weighted average useful life | 13 years 6 months |  |
Discount rate, lower range | 3.00% |  |
Discount range, upper range | 3.40% |  |
Inflation rate | 3.00% |  |
Advertising costs | $ 14,700,000 | $ 3,500,000 | $ 3,800,000
Anti-dilutive securities excluded from calculation of diluted earnings per share (in shares) | shares | 34,416 | 6,005 | 8,094
Accounting Standards Update 2017-07 |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Change in accounting principle, accounting standards update, adoption date | Aug. 29, 2021 |  |
Change in accounting principle, accounting standards update, adopted | true |  |
Change in accounting principle, accounting standards update, immaterial effect | true |  |
Accounting Standards Update 2019-12 |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Change in accounting principle, accounting standards update, adoption date | Aug. 29, 2021 |  |
Change in accounting principle, accounting standards update, adopted | true |  |
Change in accounting principle, accounting standards update, immaterial effect | true |  |
Conversion of Class B Common Stock in to Common Stock |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Conversion ratio | 1 |  |
Stock Appreciation Rights (SARs) |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Expiration period | 10 years |  |
Stock Appreciation Rights (SARs) | Certain Share-based Awards Granted During Fiscal 2020, 2019 and 2018 to Non-employee Directors | Non-Employee Directors |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Expiration period | 8 years |  |
Minimum |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Discount period, lower range | 10 years |  |
Remaining lives | 1 year |  |
Credit adjusted risk-free rate | 7.00% |  |
Maximum |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Discount period, upper range | 30 years |  |
Remaining lives | 22 years |  |
Credit adjusted risk-free rate | 7.50% |  |
Customer contracts |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Weighted average useful life | 13 years 9 months 18 days |  |
Other intangible assets |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Weighted average useful life | 6 years 1 month 6 days |  |
Core Laundry Operations |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Percentage of revenues recognized over time | 88.40% | 95.80% | 94.70%
Percentage of revenues recognized at a point in time | 11.60% | 4.20% | 5.30%
Specialty Garments |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Percentage of revenues recognized over time | 83.80% | 81.80% | 79.20%
Percentage of revenues recognized at a point in time | 16.20% | 18.20% | 20.80%
First Aid |  |  |
Summary of Significant Accounting Policies [Line Items] |  |  |
Percentage of revenues recognized at a point in time | 100.00% |  |

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 Common stock conversion ratio. + References No definition available. + Details
Name: | unf_CommonStockConversionRatio
Namespace Prefix: | unf_
Data Type: | xbrli:pureItemType
Balance Type: | na
Period Type: | duration

X
- Definition Credit adjusted risk free rate. + References No definition available. + Details
Name: | unf_CreditAdjustedRiskFreeRate
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Environmental contingencies inflation rate. + References No definition available. + Details
Name: | unf_EnvironmentalContingenciesInflationRate
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum useful life of rental merchandise assets in service. + References No definition available. + Details
Name: | unf_RentalMerchandiseUsefulLifeMaximum
Namespace Prefix: | unf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition The minimum useful life of rental merchandise assets in service. + References No definition available. + Details
Name: | unf_RentalMerchandiseUsefulLifeMinimum
Namespace Prefix: | unf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue From Contracts With Customers, Percentage Of Revenues From Route Servicing Fees + References No definition available. + Details
Name: | unf_RevenueFromContractsWithCustomersPercentageOfRevenuesFromRouteServicingFees
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue, Performance Obligation, Percentage Of Revenues Satisfied At A Point In Time + References No definition available. + Details
Name: | unf_RevenuePerformanceObligationPercentageOfRevenuesSatisfiedAtAPointInTime
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Revenue, Performance Obligation, Percentage Of Revenues Satisfied Over Time + References No definition available. + Details
Name: | unf_RevenuePerformanceObligationPercentageOfRevenuesSatisfiedOverTime
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site contingency discount rate lower range. + References No definition available. + Details
Name: | unf_SiteContingencyDiscountRateLowerRange
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site contingency discount rate upper range. + References No definition available. + Details
Name: | unf_SiteContingencyDiscountRateUpperRange
Namespace Prefix: | unf_
Data Type: | dtr-types:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site contingency discounted period lower range. + References No definition available. + Details
Name: | unf_SiteContingencyDiscountedPeriodLowerRange
Namespace Prefix: | unf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Site contingency discounted period upper range. + References No definition available. + Details
Name: | unf_SiteContingencyDiscountedPeriodUpperRange
Namespace Prefix: | unf_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Summary of significant accounting policies. + References No definition available. + Details
Name: | unf_SummaryOfSignificantAccountingPoliciesLineItems
Namespace Prefix: | unf_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount charged to advertising expense for the period, which are expenses incurred with the objective of increasing revenue for a specified brand, product or product line. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 720 -SubTopic 35 -Section 50 -Paragraph 1 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=6420018&loc=d3e36677-107848 + Details
Name: | us-gaap_AdvertisingExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition The amount of expense recognized in the current period for the periodic realization of capitalized fees that were paid to salespeople, distributors, brokers, and agents at the time of the conclusion of the sale. As a noncash expense, this element is added back to net income when calculating cash provided by or used in operations using the indirect method. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.3) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 + Details
Name: | us-gaap_AmortizationOfDeferredSalesCommissions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Securities (including those issuable pursuant to contingent stock agreements) that could potentially dilute basic earnings per share (EPS) or earnings per unit (EPU) in the future that were not included in the computation of diluted EPS or EPU because to do so would increase EPS or EPU amounts or decrease loss per share or unit amounts for the period presented. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=124432515&loc=d3e3550-109257 + Details
Name: | us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as current. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126905575&loc=SL49131252-203054 + Details
Name: | us-gaap_CapitalizedContractCostNetCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount, after accumulated amortization and accumulated impairment loss, of asset recognized from cost incurred to obtain or fulfill contract with customer; classified as noncurrent. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 340 -SubTopic 40 -Section 50 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126905575&loc=SL49131252-203054 + Details
Name: | us-gaap_CapitalizedContractCostNetNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Indicates (true false) whether accounting standards update was adopted. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 65 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=121483254&loc=SL120254523-199619 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 65 -Paragraph 8 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 926 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 926 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 7 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 7 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120254519-210437 Reference 17: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL120154346-209984 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 848 -SubTopic 10 -Section 65 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 65 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 65 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 848 -SubTopic 10 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 832 -SubTopic 10 -Section 65 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232 + Details
Name: | us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdopted
Namespace Prefix: | us-gaap_
Data Type: | xbrli:booleanItemType
Balance Type: | na
Period Type: | instant

X
- Definition Date accounting standards update was adopted, in YYYY-MM-DD format. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (a)(1) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 7 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 832 -SubTopic 10 -Section 65 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128342835&loc=SL128342857-244232 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 8: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 65 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984 Reference 9: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 105 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126987489&loc=SL124442142-165695 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 3 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120320025-210437 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 926 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 7 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL122642865-165497 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (a)(3) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124501264&loc=SL117420844-207641 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 848 -SubTopic 10 -Section 65 -Paragraph 1 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=125980421&loc=SL122150809-237846 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 Reference 25: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 65 -Paragraph 3 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL126732908-238011 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL120154346-209984 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 65 -Paragraph 8 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 20 -Section 65 -Paragraph 3 -Subparagraph (d) -URI https://asc.fasb.org/extlink&oid=128092918&loc=SL128093175-196984 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 848 -SubTopic 10 -Section 65 -Paragraph 2 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=125980421&loc=SL125981372-237846 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 20 -Section 65 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=121483254&loc=SL120254523-199619 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 926 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=120154821&loc=SL120154904-197079 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 6 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL121967933-165497 Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 2 -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL120254519-210437 Reference 36: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 65 -Paragraph 5 -URI https://asc.fasb.org/extlink&oid=126983955&loc=SL120254526-165497 Reference 37: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 842 -SubTopic 10 -Section 65 -Paragraph 5 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=128293352&loc=SL126838806-209984 + Details
Name: | us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateAdoptionDate
Namespace Prefix: | us-gaap_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | instant

X
- Definition Indicates (true false) whether effect from applying amendment to accounting standards is immaterial. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section S99 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=122038215&loc=d3e31010-122693 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 20 -Section 65 -Paragraph 2 -Subparagraph (d)(1) -URI https://asc.fasb.org/extlink&oid=126986314&loc=SL124402458-218513 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 65 -Paragraph 8 -Subparagraph (e)(3) -URI https://asc.fasb.org/extlink&oid=126983759&loc=SL121830611-158277 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 326 -SubTopic 10 -Section 65 -Paragraph 4 -Subparagraph (e)(1) -URI https://asc.fasb.org/extlink&oid=122640432&loc=SL121648383-210437 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 + Details
Name: | us-gaap_ChangeInAccountingPrincipleAccountingStandardsUpdateImmaterialEffect
Namespace Prefix: | us-gaap_
Data Type: | xbrli:booleanItemType
Balance Type: | na
Period Type: | instant

X
- Definition Useful life of finite-lived intangible assets, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_FiniteLivedIntangibleAssetUsefulLife
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Total loss recognized during the period from the impairment of goodwill plus the loss recognized in the period resulting from the impairment of the carrying amount of intangible assets, other than goodwill. + References No definition available. + Details
Name: | us-gaap_GoodwillAndIntangibleAssetImpairment
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Number of segments reported by the entity. A reportable segment is a component of an entity for which there is an accounting requirement to report separate financial information on that component in the entity's financial statements. + References Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 18 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8672-108599 + Details
Name: | us-gaap_NumberOfReportableSegments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period from grant date that an equity-based award expires, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(2) -URI https://asc.fasb.org/extlink&oid=128089324&loc=d3e5070-113901 + Details
Name: | us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of investments including trading securities, available-for-sale securities, held-to-maturity securities, and short-term investments classified as other and current. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(4)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(5)) -URI https://asc.fasb.org/extlink&oid=126897435&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(8)) -URI https://asc.fasb.org/extlink&oid=120391452&loc=d3e13212-122682 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(1)(g)) -URI https://asc.fasb.org/extlink&oid=126734703&loc=d3e572229-122910 + Details
Name: | us-gaap_ShortTermInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=unf_AccountingStandardUpdate201707Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AdjustmentsForNewAccountingPronouncementsAxis=us-gaap_AccountingStandardsUpdate201912Member
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_ConversionOfStockByUniqueDescriptionAxis=unf_ConversionOfClassBCommonStockIntoCommonStockMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_AwardTypeAxis=us-gaap_StockAppreciationRightsSARSMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_VestingAxis=unf_CertainShareBasedAwardsGrantedDuringFiscal20202019And2018ToNonemployeeDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_TitleOfIndividualAxis=unf_NonEmployeeDirectorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | srt_RangeAxis=srt_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_CustomerContractsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis=us-gaap_OtherIntangibleAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=unf_USandCanadianRentalandCleaningMFGandCorporateSegmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=unf_SpecialtyGarmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_StatementBusinessSegmentsAxis=unf_FirstAidMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |