XML 69 R43.htm IDEA: XBRL DOCUMENT
v3.21.1

Commitments and Contingencies (Details) | Sep. 20, 2018 subclass | Apr. 30, 2021 USD ($)
--- | --- | ---
Loss Contingencies [Line Items] |  |
Standby letters of credit |  | $ 149,200,000
Surety bonds |  | 600,700,000
Bucio |  |
Loss Contingencies [Line Items] |  |
Loss contingency, number of certified subclasses | subclass | 4 |
Energy Savings Contracts |  |
Loss Contingencies [Line Items] |  |
Guarantee obligation |  | 206,500,000
Minimum |  |
Loss Contingencies [Line Items] |  |
Amount of reasonably possible loss |  | 0
Maximum |  |
Loss Contingencies [Line Items] |  |
Amount of reasonably possible loss |  | 8,000,000
Pending Litigation |  |
Loss Contingencies [Line Items] |  |
Loss contingency amount accrued for probable losses |  | 14,600,000
Pending Litigation | Bucio |  |
Loss Contingencies [Line Items] |  |
Loss contingency amount accrued for probable losses |  | 30,000,000
Amount of reasonably possible loss |  | $ 160,000,000

X
- Definition The total amount of guaranteed energy savings. + References No definition available. + Details
Name: | abm_GuaranteeObligation
Namespace Prefix: | abm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Loss Contingency, Number Of Certified Subclasses + References No definition available. + Details
Name: | abm_LossContingencyNumberOfCertifiedSubclasses
Namespace Prefix: | abm_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Surety Bonds + References No definition available. + Details
Name: | abm_SuretyBonds
Namespace Prefix: | abm_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The total amount of the contingent obligation under letters of credit outstanding as of the reporting date. + References No definition available. + Details
Name: | us-gaap_LettersOfCreditOutstandingAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_LossContingenciesLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of loss contingency liability. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14326-108349 + Details
Name: | us-gaap_LossContingencyAccrualAtCarryingValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Reflects the estimated amount of loss from the specified contingency as of the balance sheet date. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 4 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14435-108349 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 450 -SubTopic 20 -Section 50 -Paragraph 9 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=121557415&loc=d3e14557-108349 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 460 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=121555522&loc=d3e12021-110248 + Details
Name: | us-gaap_LossContingencyEstimateOfPossibleLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | srt_LitigationCaseAxis=abm_BucioMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_GuaranteeObligationsByNatureAxis=abm_EnergySavingsContractsMember
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_LitigationStatusAxis=us-gaap_PendingLitigationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |