$ABM
ABM INDUSTRIES INC /DE/ Stock $abm

$abm Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000077149720000018 Filed on December 17, 2020

Income Statement

Concept	2020 Q4	2020 Q3	2020 Q2
Revenue	$1.485B	$1.394B	$1.496B
YoY Change	-9.92%	-15.4%	-6.19%
Cost Of Revenue	$1.227B	$1.175B	$1.306B
YoY Change	-15.57%	-19.2%	-7.64%
Gross Profit	$242.4M	$219.2M	$189.9M
YoY Change	24.5%	13.05%	5.21%
Gross Profit Margin	16.33%	15.72%	12.69%
Selling, General & Admin	$170.3M	$113.7M	$119.4M
YoY Change	52.05%	-5.09%	10.15%
% of Gross Profit	70.26%	51.87%	62.88%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$23.20M	$24.10M	$24.70M
YoY Change	-10.77%	-12.36%	-9.19%
% of Gross Profit	9.57%	10.99%	13.01%
Operating Expenses	$182.1M	$113.7M	$119.4M
YoY Change	44.98%	-5.09%	10.15%
Operating Profit	$60.30M	$93.60M	-$116.7M
YoY Change	-12.74%	63.35%	-314.13%
Interest Expense	-$9.900M	$13.80M	$10.50M
YoY Change	-12.39%	6.98%	-17.97%
% of Operating Profit	-16.42%	14.74%
Other Income/Expense, Net			$100.0K
YoY Change
Pretax Income	$63.00M	$80.00M	-$126.2M
YoY Change	14.34%	77.78%	-396.94%
Income Tax	$9.900M	$24.00M	$10.60M
% Of Pretax Income	15.71%	30.0%
Net Earnings	$53.10M	$56.00M	-$136.8M
YoY Change	10.86%	52.17%	-560.61%
Net Earnings / Revenue	3.58%	4.02%	-9.14%
Basic Earnings Per Share	$0.79	$0.84	-$2.05
Diluted Earnings Per Share	$0.78	$0.83	-$2.05
COMMON SHARES
Basic Shares Outstanding	66.76M shares	66.90M shares	66.90M shares
Diluted Shares Outstanding		67.20M shares	66.90M shares

Balance Sheet

Concept	2020 Q4	2020 Q3	2020 Q2
SHORT-TERM ASSETS
Cash & Short-Term Investments	$394.2M	$229.4M	$555.9M
YoY Change	573.85%	279.17%	935.2%
Cash & Equivalents	$394.2M	$229.4M	$555.9M
Short-Term Investments
Other Short-Term Assets	$55.90M	$69.10M	$64.20M
YoY Change	0.72%	29.16%	26.13%
Inventory
Prepaid Expenses	$85.40M	$95.80M	$75.00M
Receivables	$906.4M	$918.0M	$1.020B
Other Receivables	$0.00	$0.00	$0.00
Total Short-Term Assets	$1.442B	$1.312B	$1.715B
YoY Change	13.05%	-0.53%	33.89%
LONG-TERM ASSETS
Property, Plant & Equipment	$133.7M	$137.1M	$140.9M
YoY Change	-11.04%	-6.8%	-1.88%
Goodwill	$1.671B	$1.672B	$1.669B
YoY Change	-8.94%	-8.73%	-9.07%
Intangibles
YoY Change
Long-Term Investments	$11.00M	$10.90M	$10.60M
YoY Change	23.6%	-27.81%	-26.9%
Other Assets	$136.1M	$128.2M	$121.6M
YoY Change	13.13%	6.66%	-5.81%
Total Long-Term Assets	$2.335B	$2.356B	$2.364B
YoY Change	-3.4%	-2.83%	-3.46%
TOTAL ASSETS
Total Short-Term Assets	$1.442B	$1.312B	$1.715B
Total Long-Term Assets	$2.335B	$2.356B	$2.364B
Total Assets	$3.777B	$3.668B	$4.079B
YoY Change	2.28%	-2.02%	9.36%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$273.3M	$221.9M	$249.4M
YoY Change	-2.64%	-10.88%	7.18%
Accrued Expenses	$396.7M	$360.2M	$378.8M
YoY Change	6.33%	-3.54%	6.67%
Deferred Revenue	$36.40M	$42.30M	$34.60M
YoY Change	-4.21%	0.0%	-31.49%
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$116.7M	$86.60M	$87.40M
YoY Change	104.02%	65.9%	85.56%
Total Short-Term Liabilities	$986.9M	$877.4M	$941.2M
YoY Change	9.36%	0.0%	10.59%
LONG-TERM LIABILITIES
Long-Term Debt	$603.0M	$664.2M	$1.106B
YoY Change	-18.97%	-23.85%	22.11%
Other Long-Term Liabilities	$168.1M	$118.3M	$77.50M
YoY Change	185.88%	56.48%	9.31%
Total Long-Term Liabilities	$771.1M	$782.5M	$1.183B
YoY Change	-3.97%	-17.44%	21.18%
TOTAL LIABILITIES
Total Short-Term Liabilities	$986.9M	$877.4M	$941.2M
Total Long-Term Liabilities	$771.1M	$782.5M	$1.183B
Total Liabilities	$2.277B	$2.217B	$2.684B
YoY Change	5.86%	-1.04%	19.37%
SHAREHOLDERS EQUITY
Retained Earnings	$806.4M	$765.9M	$722.3M
YoY Change	-5.83%	-6.65%	-9.25%
Common Stock	$724.8M	$715.6M	$707.8M
YoY Change	2.14%	1.13%	0.93%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$1.500B	$1.451B	$1.395B
YoY Change
Total Liabilities & Shareholders Equity	$3.777B	$3.668B	$4.079B
YoY Change	2.28%	-2.02%	9.36%

Cashflow Statement

Concept	2020 Q4	2020 Q3	2020 Q2
OPERATING ACTIVITIES
Net Income	$53.10M	$56.00M	-$136.8M
YoY Change	10.86%	52.17%	-560.61%
Depreciation, Depletion And Amortization	$23.20M	$24.10M	$24.70M
YoY Change	-10.77%	-12.36%	-9.19%
Cash From Operating Activities	$198.7M	$130.8M	$162.3M
YoY Change	33.71%	126.3%	69.59%
INVESTING ACTIVITIES
Capital Expenditures	-$9.100M	-$9.800M	-$7.600M
YoY Change	-40.13%	-42.01%	-52.2%
Acquisitions
YoY Change
Other Investing Activities	-$300.0K	$1.000M	$600.0K
YoY Change	-130.0%	-1100.0%	200.0%
Cash From Investing Activities	-$9.400M	-$8.800M	-$7.000M
YoY Change	-33.8%	-48.24%	-55.41%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-26.00M	-444.9M	328.4M
YoY Change	-81.21%	1316.88%	-676.14%
NET CHANGE
Cash From Operating Activities	198.7M	130.8M	162.3M
Cash From Investing Activities	-9.400M	-8.800M	-7.000M
Cash From Financing Activities	-26.00M	-444.9M	328.4M
Net Change In Cash	163.3M	-322.9M	483.7M
YoY Change	-4182.5%	-3535.11%	2003.04%
FREE CASH FLOW
Cash From Operating Activities	$198.7M	$130.8M	$162.3M
Capital Expenditures	-$9.100M	-$9.800M	-$7.600M
Free Cash Flow	$207.8M	$140.6M	$169.9M
YoY Change	26.86%	88.22%	52.24%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2020	dei	Document Fiscal Period Focus DocumentFiscalPeriodFocus	FY
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CY2020	dei	Document Period End Date DocumentPeriodEndDate	2020-10-31
CY2020	dei	Current Fiscal Year End Date CurrentFiscalYearEndDate	--10-31
CY2020	dei	Document Transition Report DocumentTransitionReport	false
CY2020	dei	Entity File Number EntityFileNumber	1-8929
CY2020	dei	Entity Registrant Name EntityRegistrantName	ABM INDUSTRIES INC
CY2020	dei	Entity Incorporation State Country Code EntityIncorporationStateCountryCode	DE
CY2020	dei	Entity Tax Identification Number EntityTaxIdentificationNumber	94-1369354
CY2020	dei	Entity Address Address Line1 EntityAddressAddressLine1	One Liberty Plaza
CY2020	dei	Entity Address Address Line2 EntityAddressAddressLine2	7th Floor
CY2020	dei	Entity Address City Or Town EntityAddressCityOrTown	New York
CY2020	dei	Entity Address State Or Province EntityAddressStateOrProvince	NY
CY2020	dei	Entity Address Postal Zip Code EntityAddressPostalZipCode	10006
CY2020	dei	City Area Code CityAreaCode	212
CY2020	dei	Local Phone Number LocalPhoneNumber	297-0200
CY2020	dei	Security12b Title Security12bTitle	Common Stock, $0.01 par value
CY2020	dei	Trading Symbol TradingSymbol	ABM
CY2020	dei	Security Exchange Name SecurityExchangeName	NYSE
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CY2018	us-gaap	Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Before Tax OtherComprehensiveIncomeUnrealizedGainLossOnDerivativesArisingDuringPeriodBeforeTax	21900000	USD
CY2020	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-1800000	USD
CY2019	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	1600000	USD
CY2018	us-gaap	Other Comprehensive Income Foreign Currency Transaction And Translation Adjustment Net Of Tax Portion Attributable To Parent OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent	-4700000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-2400000	USD
CY2019	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	-5900000	USD
CY2018	us-gaap	Other Comprehensive Income Loss Tax Portion Attributable To Parent1 OtherComprehensiveIncomeLossTaxPortionAttributableToParent1	5900000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-6600000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	112500000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	109000000.0	USD
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.00
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.92
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.45
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.03
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.00
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.91
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.48
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.00
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.91
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.45
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.03
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.00
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.90
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.47
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66900000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66600000	shares
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66100000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	67300000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	66900000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	66400000	shares
CY2020	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.740
CY2019	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.720
CY2018	us-gaap	Common Stock Dividends Per Share Declared CommonStockDividendsPerShareDeclared	0.700
CY2020Q4	us-gaap	Stockholders Equity StockholdersEquity	1500300000	USD
CY2019Q4	us-gaap	Stockholders Equity StockholdersEquity	1542000000.0	USD
CY2018Q4	us-gaap	Stockholders Equity StockholdersEquity	1454600000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	300000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	127400000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	97800000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	100000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-100000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	1800000	USD
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	200000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	127500000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	95900000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	96400000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	107400000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	112500000	USD
CY2020	abm	Proceeds From Derivative Instrument Operating Activities ProceedsFromDerivativeInstrumentOperatingActivities	0	USD
CY2019	abm	Proceeds From Derivative Instrument Operating Activities ProceedsFromDerivativeInstrumentOperatingActivities	0	USD
CY2018	abm	Proceeds From Derivative Instrument Operating Activities ProceedsFromDerivativeInstrumentOperatingActivities	25900000	USD
CY2020	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	172800000	USD
CY2019	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	0	USD
CY2018	us-gaap	Goodwill And Intangible Asset Impairment GoodwillAndIntangibleAssetImpairment	26500000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-36600000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	9700000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	-23700000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	20300000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	17500000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	17000000.0	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	19600000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	6700000	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	6400000	USD
CY2020	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-6700000	USD
CY2019	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-5700000	USD
CY2018	us-gaap	Amortization Of Deferred Hedge Gains AmortizationOfDeferredHedgeGains	-2500000	USD
CY2020	us-gaap	Accretion Expense AccretionExpense	800000	USD
CY2019	us-gaap	Accretion Expense AccretionExpense	800000	USD
CY2018	us-gaap	Accretion Expense AccretionExpense	800000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-2100000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	600000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	-500000	USD
CY2020	abm	Provision On Other Assets ProvisionOnOtherAssets	17600000	USD
CY2019	abm	Provision On Other Assets ProvisionOnOtherAssets	0	USD
CY2018	abm	Provision On Other Assets ProvisionOnOtherAssets	0	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	2200000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	3000000.0	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	3200000	USD
CY2020	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	100000	USD
CY2019	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	5400000	USD
CY2018	us-gaap	Equity Method Investment Dividends Or Distributions EquityMethodInvestmentDividendsOrDistributions	1900000	USD
CY2020	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-141400000	USD
CY2019	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	78300000	USD
CY2018	us-gaap	Increase Decrease In Receivables IncreaseDecreaseInReceivables	-16000000.0	USD
CY2020	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	15500000	USD
CY2019	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	13200000	USD
CY2018	us-gaap	Increase Decrease In Prepaid Deferred Expense And Other Assets IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets	-2400000	USD
CY2020	abm	Increase Decrease In Operating Lease Right Of Use Asset IncreaseDecreaseInOperatingLeaseRightOfUseAsset	-24400000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	10400000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	-4500000	USD
CY2018	us-gaap	Increase Decrease In Other Noncurrent Assets IncreaseDecreaseInOtherNoncurrentAssets	-11300000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-53500000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	85800000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable And Accrued Liabilities IncreaseDecreaseInAccountsPayableAndAccruedLiabilities	-1500000	USD
CY2020	abm	Increase Decrease In Lease Liabilities Noncurrent IncreaseDecreaseInLeaseLiabilitiesNoncurrent	-22900000	USD
CY2020	us-gaap	Increase Decrease In Self Insurance Reserve IncreaseDecreaseInSelfInsuranceReserve	5700000	USD
CY2019	us-gaap	Increase Decrease In Self Insurance Reserve IncreaseDecreaseInSelfInsuranceReserve	3900000	USD
CY2018	us-gaap	Increase Decrease In Self Insurance Reserve IncreaseDecreaseInSelfInsuranceReserve	13900000	USD
CY2020	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	7600000	USD
CY2019	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	3200000	USD
CY2018	us-gaap	Increase Decrease In Accrued Income Taxes Payable IncreaseDecreaseInAccruedIncomeTaxesPayable	700000	USD
CY2020	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	96200000	USD
CY2019	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-8700000	USD
CY2018	us-gaap	Increase Decrease In Other Noncurrent Liabilities IncreaseDecreaseInOtherNoncurrentLiabilities	-1200000	USD
CY2020	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	457200000	USD
CY2019	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	135300000	USD
CY2018	us-gaap	Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities AdjustmentsToReconcileNetIncomeLossToCashProvidedByUsedInOperatingActivities	203700000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	457400000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	262800000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities Continuing Operations NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	299700000	USD
CY2020	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	100000	USD
CY2019	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	-100000	USD
CY2018	us-gaap	Cash Provided By Used In Operating Activities Discontinued Operations CashProvidedByUsedInOperatingActivitiesDiscontinuedOperations	21200000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	457500000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	262700000	USD
CY2020	us-gaap	Proceeds From Sale Of Other Assets Investing Activities ProceedsFromSaleOfOtherAssetsInvestingActivities	5500000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	320900000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	38000000.0	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	59600000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	50900000	USD
CY2019	us-gaap	Proceeds From Sale Of Other Assets Investing Activities ProceedsFromSaleOfOtherAssetsInvestingActivities	1300000	USD
CY2018	us-gaap	Proceeds From Sale Of Other Assets Investing Activities ProceedsFromSaleOfOtherAssetsInvestingActivities	2300000	USD
CY2020	abm	Divestiture Of Businesses Adjustments DivestitureOfBusinessesAdjustments	0	USD
CY2019	abm	Divestiture Of Businesses Adjustments DivestitureOfBusinessesAdjustments	0	USD
CY2018	abm	Divestiture Of Businesses Adjustments DivestitureOfBusinessesAdjustments	1900000	USD
CY2020	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	5000000.0	USD
CY2019	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	0	USD
CY2018	us-gaap	Proceeds From Maturities Prepayments And Calls Of Available For Sale Securities ProceedsFromMaturitiesPrepaymentsAndCallsOfAvailableForSaleSecurities	2900000	USD
CY2020	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	0	USD
CY2019	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	0	USD
CY2018	us-gaap	Payments To Acquire Equity Method Investments PaymentsToAcquireEquityMethodInvestments	400000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-27500000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-58300000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	-48100000	USD
CY2020	abm	Taxes Withheldand Proceedsfrom Issuanceof Share Based Compensation Awards TaxesWithheldandProceedsfromIssuanceofShareBasedCompensationAwards	-900000	USD
CY2019	abm	Taxes Withheldand Proceedsfrom Issuanceof Share Based Compensation Awards TaxesWithheldandProceedsfromIssuanceofShareBasedCompensationAwards	-1300000	USD
CY2018	abm	Taxes Withheldand Proceedsfrom Issuanceof Share Based Compensation Awards TaxesWithheldandProceedsfromIssuanceofShareBasedCompensationAwards	-1000000.0	USD
CY2020	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	5100000	USD
CY2019	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2018	us-gaap	Payments For Repurchase Of Common Stock PaymentsForRepurchaseOfCommonStock	0	USD
CY2020	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	49300000	USD
CY2019	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	47700000	USD
CY2018	us-gaap	Payments Of Dividends Common Stock PaymentsOfDividendsCommonStock	46000000.0	USD
CY2020	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	4400000	USD
CY2019	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	0	USD
CY2018	us-gaap	Payments Of Financing Costs PaymentsOfFinancingCosts	100000	USD
CY2020	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1058500000	USD
CY2019	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1755900000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	49600000	USD
CY2020	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-200000	USD
CY2018	us-gaap	Proceeds From Issuance Of Long Term Debt ProceedsFromIssuanceOfLongTermDebt	1184200000	USD
CY2020	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1141600000	USD
CY2019	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1896500000	USD
CY2018	us-gaap	Repayments Of Long Term Debt RepaymentsOfLongTermDebt	1426400000	USD
CY2020	us-gaap	Proceeds From Repayments Of Bank Overdrafts ProceedsFromRepaymentsOfBankOverdrafts	41200000	USD
CY2019	us-gaap	Proceeds From Repayments Of Bank Overdrafts ProceedsFromRepaymentsOfBankOverdrafts	-200000	USD
CY2018	us-gaap	Proceeds From Repayments Of Bank Overdrafts ProceedsFromRepaymentsOfBankOverdrafts	-8500000	USD
CY2020	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	11100000	USD
CY2019	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	8100000	USD
CY2018	us-gaap	Proceeds From Construction Loans Payable ProceedsFromConstructionLoansPayable	5400000	USD
CY2020	us-gaap	Repayments Of Long Term Capital Lease Obligations RepaymentsOfLongTermCapitalLeaseObligations	3400000	USD
CY2019	us-gaap	Repayments Of Long Term Capital Lease Obligations RepaymentsOfLongTermCapitalLeaseObligations	3100000	USD
CY2018	us-gaap	Repayments Of Long Term Capital Lease Obligations RepaymentsOfLongTermCapitalLeaseObligations	3300000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-94100000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-184800000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-295800000	USD
CY2019	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-200000	USD
CY2018	us-gaap	Effect Of Exchange Rate On Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations EffectOfExchangeRateOnCashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	-700000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	335700000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	19400000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-23700000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	58500000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	39100000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	62800000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	394200000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	58500000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents	39100000	USD
CY2020	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	82200000	USD
CY2019	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	20600000	USD
CY2018	us-gaap	Income Taxes Paid Net IncomeTaxesPaidNet	-1000000.0	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	32900000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	39900000	USD
CY2020	us-gaap	Nature Of Operations NatureOfOperations	THE COMPANY AND NATURE OF OPERATIONS<div style="margin-top:9pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:120%">ABM is a leading provider of integrated facility services with a mission to </span><span style="color:#326abd;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:120%">make a difference, every person, every day</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:120%">. We are organized into four industry groups and one Technical Solutions segment: </span></div><div style="margin-top:9pt;text-align:justify"><span><br/></span></div><div style="margin-bottom:9pt;margin-top:3pt;text-align:center"><img alt="abm-20201031_g10.jpg" src="abm-20201031_g10.jpg" style="height:94px;margin-bottom:5pt;vertical-align:text-bottom;width:521px"/></div><div style="margin-top:9pt;text-align:justify;text-indent:36pt"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:120%">Through these groups, we offer janitorial, facilities engineering, parking, and specialized mechanical and electrical technical solutions, on a standalone basis or in combination with other services.</span></div>
CY2020	abm	Number Of Industry Groups NumberOfIndustryGroups	4	industry_group
CY2020	abm	Number Of Technical Solution Segments NumberOfTechnicalSolutionSegments	1	segment
CY2020	us-gaap	Use Of Estimates UseOfEstimates	The preparation of consolidated financial statements in accordance with U.S. GAAP requires our management to make certain estimates that affect reported amounts. We base our estimates on historical experience, known or expected trends, independent valuations, and various other assumptions that we believe to be reasonable under the circumstances. As future events and their effects cannot be determined with precision, actual results could differ significantly from these estimates.
CY2020	abm	Social Security Tax Employer Deferral Cares Act SocialSecurityTaxEmployerDeferralCARESAct	101000000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	11000000.0	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	8900000	USD
CY2018Q4	us-gaap	Equity Method Investments EquityMethodInvestments	11300000	USD
CY2020Q4	us-gaap	Auction Rate Securities Noncurrent AuctionRateSecuritiesNoncurrent	0	USD
CY2020	us-gaap	Advertising Expense AdvertisingExpense	1800000	USD
CY2019	us-gaap	Advertising Expense AdvertisingExpense	1700000	USD
CY2018	us-gaap	Advertising Expense AdvertisingExpense	2300000	USD
CY2019Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	167500000	USD
CY2019Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	36300000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	158200000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	155200000	USD
CY2019Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	154200000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	78800000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	58800000	USD
CY2020	abm	Contract With Customer Liability Revenue Recognized During The Period ContractWithCustomerLiabilityRevenueRecognizedDuringThePeriod	317100000	USD
CY2020Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	36400000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	5987600000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	6498600000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation RevenueRemainingPerformanceObligation	266300000	USD
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation Percentage RevenueRemainingPerformanceObligationPercentage	0.61
CY2020Q4	us-gaap	Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Period1 RevenueRemainingPerformanceObligationExpectedTimingOfSatisfactionPeriod1	P12M
CY2020Q4	abm	Contractwith Customer Asset Billed Trade Receivable Net Current ContractwithCustomerAssetBilledTradeReceivableNetCurrent	835800000	USD
CY2019Q4	abm	Contractwith Customer Asset Billed Trade Receivable Net Current ContractwithCustomerAssetBilledTradeReceivableNetCurrent	978700000	USD
CY2020Q4	abm	Contractwith Customer Asset Unbilled Trade Receivables Net Current ContractwithCustomerAssetUnbilledTradeReceivablesNetCurrent	53900000	USD
CY2019Q4	abm	Contractwith Customer Asset Unbilled Trade Receivables Net Current ContractwithCustomerAssetUnbilledTradeReceivablesNetCurrent	56900000	USD
CY2020Q4	abm	Contractwith Customer Asset Costs Incurredin Excessof Amounts Billed Current ContractwithCustomerAssetCostsIncurredinExcessofAmountsBilledCurrent	52200000	USD
CY2019Q4	abm	Contractwith Customer Asset Costs Incurredin Excessof Amounts Billed Current ContractwithCustomerAssetCostsIncurredinExcessofAmountsBilledCurrent	72600000	USD
CY2020Q4	abm	Contractwith Customer Asset Capitalized Commissions ContractwithCustomerAssetCapitalizedCommissions	25200000	USD
CY2019Q4	abm	Contractwith Customer Asset Capitalized Commissions ContractwithCustomerAssetCapitalizedCommissions	21800000	USD
CY2020	abm	Contractwith Customer Asset Increase Decreasefor New Capitalized Costs ContractwithCustomerAssetIncreaseDecreaseforNewCapitalizedCosts	16400000	USD
CY2020	us-gaap	Capitalized Contract Cost Amortization CapitalizedContractCostAmortization	13000000.0	USD
CY2020	us-gaap	Capitalized Contract Cost Impairment Loss CapitalizedContractCostImpairmentLoss	0	USD
CY2019Q4	us-gaap	Contract With Customer Liability Current ContractWithCustomerLiabilityCurrent	38000000.0	USD
CY2020	abm	Contractwith Customer Liability Increase Decreasefor Additional Contract Liabilities ContractwithCustomerLiabilityIncreaseDecreaseforAdditionalContractLiabilities	315500000	USD
CY2020Q4	us-gaap	Operating Lease Right Of Use Asset OperatingLeaseRightOfUseAsset	143100000	USD
CY2020Q4	us-gaap	Finance Lease Right Of Use Asset FinanceLeaseRightOfUseAsset	6100000	USD
CY2020Q4	abm	Lessee Leases Right Of Use Assets LesseeLeasesRightOfUseAssets	149200000	USD
CY2020Q4	us-gaap	Operating Lease Liability Current OperatingLeaseLiabilityCurrent	35000000.0	USD
CY2020Q4	us-gaap	Finance Lease Liability Current FinanceLeaseLiabilityCurrent	2300000	USD
CY2020Q4	us-gaap	Operating Lease Liability Noncurrent OperatingLeaseLiabilityNoncurrent	131400000	USD
CY2020Q4	us-gaap	Finance Lease Liability Noncurrent FinanceLeaseLiabilityNoncurrent	2800000	USD
CY2020Q4	abm	Lease Liability LeaseLiability	171400000	USD
CY2020Q4	abm	Finance Lease Right Of Use Asset Accumulated Depreciation FinanceLeaseRightOfUseAssetAccumulatedDepreciation	13600000	USD
CY2020	us-gaap	Lease Cost LeaseCost	100400000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	96400000	USD
CY2020	abm	Finance Lease Cost FinanceLeaseCost	4000000.0	USD
CY2020	us-gaap	Finance Lease Right Of Use Asset Amortization FinanceLeaseRightOfUseAssetAmortization	3500000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due Next Twelve Months FinanceLeaseLiabilityPaymentsDueNextTwelveMonths	3300000	USD
CY2020	us-gaap	Finance Lease Interest Expense FinanceLeaseInterestExpense	500000	USD
CY2020	us-gaap	Lease Cost LeaseCost	100400000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	47000000.0	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	3500000	USD
CY2020	abm	Lease Short Term And Variable Cost Total LeaseShortTermAndVariableCostTotal	50500000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	41300000	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due Year One LesseeLeasesLiabilityPaymentsDueYearOne	44600000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	34300000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due Year Two FinanceLeaseLiabilityPaymentsDueYearTwo	1700000	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due Year Two LesseeLeasesLiabilityPaymentsDueYearTwo	36000000.0	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	29200000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due Year Three FinanceLeaseLiabilityPaymentsDueYearThree	900000	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due Year Three LesseeLeasesLiabilityPaymentsDueYearThree	30100000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	24100000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due Year Four FinanceLeaseLiabilityPaymentsDueYearFour	0	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due Year Four LesseeLeasesLiabilityPaymentsDueYearFour	24100000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	18200000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due Year Five FinanceLeaseLiabilityPaymentsDueYearFive	0	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due Year Five LesseeLeasesLiabilityPaymentsDueYearFive	18200000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	43300000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due After Year Five FinanceLeaseLiabilityPaymentsDueAfterYearFive	0	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due After Year Five LesseeLeasesLiabilityPaymentsDueAfterYearFive	43300000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	190400000	USD
CY2020Q4	us-gaap	Finance Lease Liability Payments Due FinanceLeaseLiabilityPaymentsDue	5900000	USD
CY2020Q4	abm	Lessee Leases Liability Payments Due LesseeLeasesLiabilityPaymentsDue	196300000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	24000000.0	USD
CY2020Q4	us-gaap	Finance Lease Liability Undiscounted Excess Amount FinanceLeaseLiabilityUndiscountedExcessAmount	800000	USD
CY2020Q4	abm	Lessee Leases Liability Undiscounted Excess Amount LesseeLeasesLiabilityUndiscountedExcessAmount	24900000	USD
CY2020Q4	us-gaap	Operating Lease Liability OperatingLeaseLiability	166400000	USD
CY2020Q4	us-gaap	Finance Lease Liability FinanceLeaseLiability	5100000	USD
CY2020Q4	abm	Lessee Leases Liability LesseeLeasesLiability	171400000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P6Y1M6D
CY2020Q4	us-gaap	Finance Lease Weighted Average Remaining Lease Term1 FinanceLeaseWeightedAverageRemainingLeaseTerm1	P2Y
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.0414
CY2020Q4	us-gaap	Finance Lease Weighted Average Discount Rate Percent FinanceLeaseWeightedAverageDiscountRatePercent	0.0455
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	44800000	USD
CY2020	us-gaap	Finance Lease Interest Payment On Liability FinanceLeaseInterestPaymentOnLiability	500000	USD
CY2020	us-gaap	Finance Lease Principal Payments FinanceLeasePrincipalPayments	3400000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	15700000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due Current OperatingLeasesFutureMinimumPaymentsDueCurrent	42800000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due Current CapitalLeasesFutureMinimumPaymentsDueCurrent	3100000	USD
CY2019Q4	abm	Leases Future Minimum Payments Due Next Twelve Months LeasesFutureMinimumPaymentsDueNextTwelveMonths	45900000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Two Years OperatingLeasesFutureMinimumPaymentsDueInTwoYears	35500000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due In Two Years CapitalLeasesFutureMinimumPaymentsDueInTwoYears	2500000	USD
CY2019Q4	abm	Leases Future Minimum Payments Due In Two Years LeasesFutureMinimumPaymentsDueInTwoYears	38000000.0	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Three Years OperatingLeasesFutureMinimumPaymentsDueInThreeYears	30300000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due In Three Years CapitalLeasesFutureMinimumPaymentsDueInThreeYears	1300000	USD
CY2019Q4	abm	Leases Future Minimum Payments Due In Three Years LeasesFutureMinimumPaymentsDueInThreeYears	31600000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Four Years OperatingLeasesFutureMinimumPaymentsDueInFourYears	25600000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due In Four Years CapitalLeasesFutureMinimumPaymentsDueInFourYears	600000	USD
CY2019Q4	abm	Leases Future Minimum Payments Due In Four Years LeasesFutureMinimumPaymentsDueInFourYears	26200000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due In Five Years OperatingLeasesFutureMinimumPaymentsDueInFiveYears	20500000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due In Five Years CapitalLeasesFutureMinimumPaymentsDueInFiveYears	0	USD
CY2019Q4	abm	Leases Future Minimum Payments Due In Five Years LeasesFutureMinimumPaymentsDueInFiveYears	20500000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due Thereafter OperatingLeasesFutureMinimumPaymentsDueThereafter	51800000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due Thereafter CapitalLeasesFutureMinimumPaymentsDueThereafter	0	USD
CY2019Q4	abm	Leases Future Minimum Payments Due Thereafter LeasesFutureMinimumPaymentsDueThereafter	51800000	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Due OperatingLeasesFutureMinimumPaymentsDue	206500000	USD
CY2019Q4	us-gaap	Capital Leases Future Minimum Payments Due CapitalLeasesFutureMinimumPaymentsDue	7500000	USD
CY2019Q4	abm	Leases Future Minimum Payments Due LeasesFutureMinimumPaymentsDue	214000000.0	USD
CY2019Q4	us-gaap	Operating Leases Future Minimum Payments Receivable OperatingLeasesFutureMinimumPaymentsReceivable	15800000	USD
CY2017Q4	us-gaap	Restructuring Reserve RestructuringReserve	8400000	USD
CY2018	us-gaap	Restructuring Charges RestructuringCharges	25700000	USD
CY2018	us-gaap	Payments For Restructuring PaymentsForRestructuring	24700000	USD
CY2018	us-gaap	Restructuring Reserve Settled Without Cash2 RestructuringReserveSettledWithoutCash2	700000	USD
CY2018Q4	us-gaap	Restructuring Reserve RestructuringReserve	8600000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	11200000	USD
CY2019	us-gaap	Payments For Restructuring PaymentsForRestructuring	12900000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	7000000.0	USD
CY2020	us-gaap	Restructuring Charges RestructuringCharges	7600000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0.03
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.00
CY2020	us-gaap	Payments For Restructuring PaymentsForRestructuring	7900000	USD
CY2020	us-gaap	Restructuring Reserve Settled Without Cash2 RestructuringReserveSettledWithoutCash2	5400000	USD
CY2020Q4	us-gaap	Restructuring Reserve RestructuringReserve	1300000	USD
CY2020Q4	us-gaap	Restructuring And Related Cost Cost Incurred To Date1 RestructuringAndRelatedCostCostIncurredToDate1	108700000	USD
CY2020	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	200000	USD
CY2019	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	127500000	USD
CY2018	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	95900000	USD
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	100000	USD
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-100000	USD
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	1800000	USD
CY2020	us-gaap	Net Income Loss NetIncomeLoss	300000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	127400000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	97800000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66900000	shares
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66600000	shares
CY2020	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.00
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	66100000	shares
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	67300000	shares
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	66900000	shares
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	66400000	shares
CY2019	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.92
CY2018	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	1.45
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2018	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0.03
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.00
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.91
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	1.48
CY2020	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.00
CY2019	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.91
CY2018	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	1.45
CY2020	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.90
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	1.47
CY2020	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	400000	shares
CY2019	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	300000	shares
CY2018	us-gaap	Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount	400000	shares
CY2020Q4	us-gaap	Debt Securities Available For Sale Accumulated Gross Unrealized Gain Loss Before Tax DebtSecuritiesAvailableForSaleAccumulatedGrossUnrealizedGainLossBeforeTax	0	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	375000000.0	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	349800000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	241300000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	199500000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	133700000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	150300000	USD
CY2020	us-gaap	Depreciation Depreciation	48000000.0	USD
CY2019	us-gaap	Depreciation Depreciation	48900000	USD
CY2018	us-gaap	Depreciation Depreciation	46500000	USD
CY2020Q4	us-gaap	Capital Leased Assets Gross CapitalLeasedAssetsGross	19700000	USD
CY2019Q4	us-gaap	Capital Leased Assets Gross CapitalLeasedAssetsGross	20600000	USD
CY2020Q4	us-gaap	Capital Leases Lessee Balance Sheet Assets By Major Class Accumulated Deprecation CapitalLeasesLesseeBalanceSheetAssetsByMajorClassAccumulatedDeprecation	13600000	USD
CY2019Q4	us-gaap	Capital Leases Lessee Balance Sheet Assets By Major Class Accumulated Deprecation CapitalLeasesLesseeBalanceSheetAssetsByMajorClassAccumulatedDeprecation	10700000	USD
CY2020Q4	us-gaap	Capital Leases Balance Sheet Assets By Major Class Net CapitalLeasesBalanceSheetAssetsByMajorClassNet	6100000	USD
CY2019Q4	us-gaap	Capital Leases Balance Sheet Assets By Major Class Net CapitalLeasesBalanceSheetAssetsByMajorClassNet	9900000	USD
CY2018Q4	us-gaap	Goodwill Goodwill	1834800000	USD
CY2019	us-gaap	Goodwill Transfers GoodwillTransfers	0	USD
CY2019	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	600000	USD
CY2019Q4	us-gaap	Goodwill Goodwill	1835400000	USD
CY2020	us-gaap	Goodwill Foreign Currency Translation Gain Loss GoodwillForeignCurrencyTranslationGainLoss	-200000	USD
CY2020	us-gaap	Goodwill Impairment Loss GoodwillImpairmentLoss	163800000	USD
CY2020Q4	us-gaap	Goodwill Goodwill	1671400000	USD
CY2020Q4	abm	Number Of Reporting Units Evaluated For Impairment NumberOfReportingUnitsEvaluatedForImpairment	3	segment
CY2020Q4	abm	Number Of Reporting Units Evaluated For Impairment NumberOfReportingUnitsEvaluatedForImpairment	3	segment
CY2020Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	583500000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	343800000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	239700000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Gross FiniteLivedIntangibleAssetsGross	606200000	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Accumulated Amortization FiniteLivedIntangibleAssetsAccumulatedAmortization	309000000.0	USD
CY2019Q4	us-gaap	Finite Lived Intangible Assets Net FiniteLivedIntangibleAssetsNet	297200000	USD
CY2020	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	9000000.0	USD
CY2019	us-gaap	Impairment Of Intangible Assets Finitelived ImpairmentOfIntangibleAssetsFinitelived	0	USD
CY2020	us-gaap	Acquired Finite Lived Intangible Assets Weighted Average Useful Life AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife	P11Y
CY2019	us-gaap	Acquired Finite Lived Intangible Assets Weighted Average Useful Life AcquiredFiniteLivedIntangibleAssetsWeightedAverageUsefulLife	P11Y
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Next Twelve Months FiniteLivedIntangibleAssetsAmortizationExpenseNextTwelveMonths	42100000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Two FiniteLivedIntangibleAssetsAmortizationExpenseYearTwo	36800000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Three FiniteLivedIntangibleAssetsAmortizationExpenseYearThree	32200000	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Four FiniteLivedIntangibleAssetsAmortizationExpenseYearFour	28000000.0	USD
CY2020Q4	us-gaap	Finite Lived Intangible Assets Amortization Expense Year Five FiniteLivedIntangibleAssetsAmortizationExpenseYearFive	23900000	USD
CY2020Q4	abm	Insurance Policy Coverage General Liability And Automobile Liability Losses InsurancePolicyCoverageGeneralLiabilityAndAutomobileLiabilityLosses	200000000.0	USD
CY2020Q4	abm	Property Damage Policy Limit PropertyDamagePolicyLimit	75000000.0	USD
CY2020	abm	Decrease In Total Reserve Claims DecreaseInTotalReserveClaims	36600000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-30200000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-3400000	USD
CY2020Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	70100000	USD
CY2019Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	64500000	USD
CY2020	us-gaap	Schedule Of Liability For Unpaid Claims And Claims Adjustment Expense ScheduleOfLiabilityForUnpaidClaimsAndClaimsAdjustmentExpense	<div style="margin-top:9pt;text-align:justify"><span style="color:#0046ad;font-family:'Arial',sans-serif;font-size:10pt;font-style:italic;font-weight:700;line-height:120%">Casualty Program Insurance Reserves Rollforward</span></div><div style="margin-bottom:6pt;margin-top:9pt"><table style="border-collapse:collapse;display:inline-table;vertical-align:top;width:100.000%"><tr><td style="width:1.0%"/><td style="width:54.747%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.530%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.788%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.530%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.935%"/><td style="width:0.1%"/><td style="width:0.1%"/><td style="width:0.530%"/><td style="width:0.1%"/><td style="width:1.0%"/><td style="width:12.940%"/><td style="width:0.1%"/></tr><tr><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="padding:0 1pt"/><td colspan="15" style="padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Years Ended October 31,</span></td></tr><tr><td colspan="3" style="padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Times New Roman',sans-serif;font-size:8pt;font-style:italic;font-weight:400;line-height:100%;text-decoration:underline">(in millions)</span></td><td colspan="3" style="padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">2020</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">2019</span></td><td colspan="3" style="border-top:1pt solid #000000;padding:0 1pt"/><td colspan="3" style="border-top:1pt solid #000000;padding:2px 1pt;text-align:center;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">2018</span></td></tr><tr><td colspan="3" style="background-color:#dce2ef;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Net balance at beginning of year</span></td><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">443.3 </span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">427.7 </span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">412.5 </span></td><td style="background-color:#dce2ef;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Change in case reserves plus IBNR Claims </span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">—</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> current year</span></div></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">128.5 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">137.9 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">131.4 </span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#dce2ef;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Change in case reserves plus IBNR Claims </span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:9pt;font-weight:400;line-height:100%">—</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%"> prior years</span></div></td><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(30.2)</span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(3.4)</span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">10.2 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">Claims paid</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(106.8)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(119.1)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">(126.5)</span></td><td style="background-color:#ffffff;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#dce2ef;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">GCA acquisition</span></td><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">0.2 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">— </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">0.1 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><div><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Net balance, October 31</span><span style="color:#000000;font-family:'Arial',sans-serif;font-size:6.5pt;font-weight:700;line-height:100%;position:relative;top:-3.5pt;vertical-align:baseline">(1)</span></div></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">434.8 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">443.3 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td colspan="2" style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">427.7 </span></td><td style="background-color:#ffffff;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#dce2ef;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Recoverables</span></td><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">70.1 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">64.5 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#dce2ef;padding:0 1pt"/><td colspan="2" style="background-color:#dce2ef;padding:2px 0 2px 1pt;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">73.7 </span></td><td style="background-color:#dce2ef;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr><tr><td colspan="3" style="background-color:#ffffff;padding:2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:700;line-height:100%">Gross balance, October 31</span></td><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">504.9 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">507.8 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/><td colspan="3" style="background-color:#ffffff;padding:0 1pt"/><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0 2px 1pt;text-align:left;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">$</span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 0;text-align:right;vertical-align:bottom"><span style="color:#000000;font-family:'Arial',sans-serif;font-size:10pt;font-weight:400;line-height:100%">501.4 </span></td><td style="background-color:#ffffff;border-bottom:3pt double #000000;border-top:1pt solid #000000;padding:2px 1pt 2px 0;text-align:right;vertical-align:bottom"/></tr></table></div>(1) Includes reserves related to discontinued operations of approximately $0.5 million for 2020, $1.0 million for 2019, and $3.0 million for 2018.
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	443300000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	427700000	USD
CY2017Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	412500000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	128500000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	137900000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Current Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersCurrentYearClaimsAndClaimsAdjustmentExpense	131400000	USD
CY2020	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-30200000	USD
CY2019	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	-3400000	USD
CY2018	us-gaap	Supplemental Information For Property Casualty Insurance Underwriters Prior Year Claims And Claims Adjustment Expense SupplementalInformationForPropertyCasualtyInsuranceUnderwritersPriorYearClaimsAndClaimsAdjustmentExpense	10200000	USD
CY2020	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	106800000	USD
CY2019	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	119100000	USD
CY2018	us-gaap	Payments For Losses And Loss Adjustment Expense PaymentsForLossesAndLossAdjustmentExpense	126500000	USD
CY2020	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions	200000	USD
CY2019	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions	0	USD
CY2018	us-gaap	Liability For Unpaid Claims And Claims Adjustment Expense Business Acquisitions LiabilityForUnpaidClaimsAndClaimsAdjustmentExpenseBusinessAcquisitions	100000	USD
CY2020Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	434800000	USD
CY2019Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	443300000	USD
CY2018Q4	us-gaap	Liability For Claims And Claims Adjustment Expense LiabilityForClaimsAndClaimsAdjustmentExpense	427700000	USD
CY2020Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	70100000	USD
CY2019Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	64500000	USD
CY2018Q4	us-gaap	Reinsurance Recoverable For Unpaid Claims And Claims Adjustments ReinsuranceRecoverableForUnpaidClaimsAndClaimsAdjustments	73700000	USD
CY2020Q4	abm	Liabilityfor Claimsand Claims Adjustment Expense Gross LiabilityforClaimsandClaimsAdjustmentExpenseGross	504900000	USD
CY2019Q4	abm	Liabilityfor Claimsand Claims Adjustment Expense Gross LiabilityforClaimsandClaimsAdjustmentExpenseGross	507800000	USD
CY2018Q4	abm	Liabilityfor Claimsand Claims Adjustment Expense Gross LiabilityforClaimsandClaimsAdjustmentExpenseGross	501400000	USD
CY2020	abm	Disposal Group Including Discontinued Operation Liabilityfor Unpaid Claimsand Claims Adjustment Expense DisposalGroupIncludingDiscontinuedOperationLiabilityforUnpaidClaimsandClaimsAdjustmentExpense	500000	USD
CY2019	abm	Disposal Group Including Discontinued Operation Liabilityfor Unpaid Claimsand Claims Adjustment Expense DisposalGroupIncludingDiscontinuedOperationLiabilityforUnpaidClaimsandClaimsAdjustmentExpense	1000000.0	USD
CY2018	abm	Disposal Group Including Discontinued Operation Liabilityfor Unpaid Claimsand Claims Adjustment Expense DisposalGroupIncludingDiscontinuedOperationLiabilityforUnpaidClaimsandClaimsAdjustmentExpense	3000000.0	USD
CY2020Q4	abm	Instruments Used To Collateralize Insurance Obligations InstrumentsUsedToCollateralizeInsuranceObligations	226900000	USD
CY2019Q4	abm	Instruments Used To Collateralize Insurance Obligations InstrumentsUsedToCollateralizeInsuranceObligations	232600000	USD
CY2020Q4	abm	Loans Payable Current Gross LoansPayableCurrentGross	120000000.0	USD
CY2019Q4	abm	Loans Payable Current Gross LoansPayableCurrentGross	60000000.0	USD
CY2020Q4	us-gaap	Deferred Finance Costs Current Net DeferredFinanceCostsCurrentNet	3300000	USD
CY2019Q4	us-gaap	Deferred Finance Costs Current Net DeferredFinanceCostsCurrentNet	2800000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	116700000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	57200000	USD
CY2020Q4	abm	Loans Payable Noncurrent Gross LoansPayableNoncurrentGross	560000000.0	USD
CY2019Q4	abm	Loans Payable Noncurrent Gross LoansPayableNoncurrentGross	680000000.0	USD
CY2020Q4	us-gaap	Deferred Finance Costs Noncurrent Net DeferredFinanceCostsNoncurrentNet	2300000	USD
CY2019Q4	us-gaap	Deferred Finance Costs Noncurrent Net DeferredFinanceCostsNoncurrentNet	4100000	USD
CY2020Q4	us-gaap	Long Term Loans Payable LongTermLoansPayable	557700000	USD
CY2019Q4	us-gaap	Long Term Loans Payable LongTermLoansPayable	675900000	USD
CY2020Q4	us-gaap	Long Term Line Of Credit LongTermLineOfCredit	45300000	USD
CY2019Q4	us-gaap	Long Term Line Of Credit LongTermLineOfCredit	68400000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	603000000.0	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	744200000	USD
CY2020Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	153100000	USD
CY2020Q4	us-gaap	Line Of Credit Facility Remaining Borrowing Capacity LineOfCreditFacilityRemainingBorrowingCapacity	596600000	USD
CY2020	us-gaap	Debt Instrument Periodic Payment Principal DebtInstrumentPeriodicPaymentPrincipal	60000000.0	USD
CY2020Q4	us-gaap	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Net InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsNet	-4000000.0	USD
CY2020Q4	abm	Interest Rate Cash Flow Hedge Gain Loss To Be Reclassified During Next12 Months Tax InterestRateCashFlowHedgeGainLossToBeReclassifiedDuringNext12MonthsTax	-1400000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Amounts Recognized In Balance Sheet DefinedBenefitPlanAmountsRecognizedInBalanceSheet	-9600000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Amounts Recognized In Balance Sheet DefinedBenefitPlanAmountsRecognizedInBalanceSheet	-8400000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Projected Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation	17000000.0	USD
CY2019Q4	us-gaap	Defined Benefit Plan Pension Plans With Accumulated Benefit Obligations In Excess Of Plan Assets Aggregate Projected Benefit Obligation DefinedBenefitPlanPensionPlansWithAccumulatedBenefitObligationsInExcessOfPlanAssetsAggregateProjectedBenefitObligation	16100000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	7400000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	7800000	USD
CY2019	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	400000	USD
CY2018	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	400000	USD
CY2020	us-gaap	Defined Benefit Plan Expected Return On Plan Assets DefinedBenefitPlanExpectedReturnOnPlanAssets	400000	USD
CY2020	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	200000	USD
CY2019	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	600000	USD
CY2018	us-gaap	Defined Benefit Plan Net Periodic Benefit Cost DefinedBenefitPlanNetPeriodicBenefitCost	200000	USD
CY2020Q4	abm	Defined Benefit Plan Expected Future Benefit Payments Aggregate DefinedBenefitPlanExpectedFutureBenefitPaymentsAggregate	14400000	USD
CY2020Q4	abm	Numberof Defined Contribution Plans NumberofDefinedContributionPlans	4	defined_contribution_plan
CY2020	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	18200000	USD
CY2019	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	24300000	USD
CY2018	us-gaap	Defined Contribution Plan Cost Recognized DefinedContributionPlanCostRecognized	21600000	USD
CY2020Q4	us-gaap	Letters Of Credit Outstanding Amount LettersOfCreditOutstandingAmount	153100000	USD
CY2020Q4	abm	Surety Bonds SuretyBonds	632900000	USD
CY2020Q4	us-gaap	Equity Method Investment Ownership Percentage EquityMethodInvestmentOwnershipPercentage	0.33
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	500000	shares
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0	shares
CY2019	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	0	shares
CY2018	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	0	shares
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.287
CY2020	us-gaap	Stock Repurchased During Period Shares StockRepurchasedDuringPeriodShares	200000	shares
CY2020	abm	Stock Repurchase Average Cost Per Share StockRepurchaseAverageCostPerShare	36.16
CY2020	us-gaap	Stock Repurchased During Period Value StockRepurchasedDuringPeriodValue	5100000	USD
CY2020	abm	Sharebased Compensation Arrangementby Sharebased Payment Award Holding Period On Employee Stock Purchase SharebasedCompensationArrangementbySharebasedPaymentAwardHoldingPeriodOnEmployeeStockPurchase	P6M
CY2020	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	20300000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17500000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense AllocatedShareBasedCompensationExpense	17000000.0	USD
CY2020	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5700000	USD
CY2019	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	4900000	USD
CY2018	us-gaap	Employee Service Share Based Compensation Tax Benefit From Compensation Expense EmployeeServiceShareBasedCompensationTaxBenefitFromCompensationExpense	5100000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.277
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Expected Volatility Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsExpectedVolatilityRate	0.216
CY2020	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	14600000	USD
CY2019	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	12500000	USD
CY2018	us-gaap	Allocated Share Based Compensation Expense Net Of Tax AllocatedShareBasedCompensationExpenseNetOfTax	11800000	USD
CY2020	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P2Y9M21D
CY2019	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P2Y9M21D
CY2018	us-gaap	Sharebased Compensation Arrangement By Sharebased Payment Award Fair Value Assumptions Expected Term1 SharebasedCompensationArrangementBySharebasedPaymentAwardFairValueAssumptionsExpectedTerm1	P2Y9M21D
CY2020	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.015
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.025
CY2018	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Fair Value Assumptions Risk Free Interest Rate ShareBasedCompensationArrangementByShareBasedPaymentAwardFairValueAssumptionsRiskFreeInterestRate	0.020
CY2020Q4	us-gaap	Share Price SharePrice	37.99
CY2019Q4	us-gaap	Share Price SharePrice	34.92
CY2018Q4	us-gaap	Share Price SharePrice	39.02
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	45200000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	137100000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	94800000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	8100000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	23100000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-7100000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	53300000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	160200000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments	87700000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	59300000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	6400000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	4300000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	28600000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	10700000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	7300000	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	1700000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	5900000	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	3900000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-23200000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	8500000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-21800000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-12500000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	1600000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	-200000	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-900000	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-400000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-1700000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	53100000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	32700000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-8200000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.020
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2019	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.210
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.233
CY2020	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	-0.006
CY2019	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.059
CY2018	us-gaap	Effective Income Tax Rate Reconciliation State And Local Income Taxes EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes	0.069
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.047
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.039
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Tax Credits EffectiveIncomeTaxRateReconciliationTaxCredits	0.078
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.013
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	-0.010
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate	0.013
CY2020	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	400000	USD
CY2019Q4	abm	Tax Benefits Lapseof Statuteof Limitations TaxBenefitsLapseofStatuteofLimitations	1800000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.044
CY2019	abm	Effective Income Tax Rate Reconciliation Deduction Energy Efficient Incentives Percent EffectiveIncomeTaxRateReconciliationDeductionEnergyEfficientIncentivesPercent	0
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.008
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Other Adjustments EffectiveIncomeTaxRateReconciliationOtherAdjustments	-0.067
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.016
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.007
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Share Based Compensation Cost EffectiveIncomeTaxRateReconciliationNondeductibleExpenseShareBasedCompensationCost	-0.039
CY2020	abm	Effective Income Tax Rate Reconciliation Deduction Energy Efficient Incentives Percent EffectiveIncomeTaxRateReconciliationDeductionEnergyEfficientIncentivesPercent	0.038
CY2018	abm	Effective Income Tax Rate Reconciliation Deduction Energy Efficient Incentives Percent EffectiveIncomeTaxRateReconciliationDeductionEnergyEfficientIncentivesPercent	0.032
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0.817
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Impairment Losses EffectiveIncomeTaxRateReconciliationNondeductibleExpenseImpairmentLosses	0.044
CY2020	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Transition Tax On Accumulated Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActTransitionTaxOnAccumulatedForeignEarningsPercent	0
CY2019	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Transition Tax On Accumulated Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActTransitionTaxOnAccumulatedForeignEarningsPercent	-0.011
CY2018	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Transition Tax On Accumulated Foreign Earnings Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActTransitionTaxOnAccumulatedForeignEarningsPercent	0.051
CY2020	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Deferred Tax Remeasurement Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActDeferredTaxRemeasurementPercent	0
CY2019	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Deferred Tax Remeasurement Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActDeferredTaxRemeasurementPercent	-0.003
CY2018	abm	Effective Income Tax Rate Reconciliation Tax Cuts And Jobs Act Deferred Tax Remeasurement Percent EffectiveIncomeTaxRateReconciliationTaxCutsAndJobsActDeferredTaxRemeasurementPercent	-0.315
CY2018	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.233
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Measurement Period Adjustment Income Tax Expense Benefit TaxCutsAndJobsActOf2017MeasurementPeriodAdjustmentIncomeTaxExpenseBenefit	-29600000	USD
CY2018	us-gaap	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit	4500000	USD
CY2019	us-gaap	Tax Cuts And Jobs Act Of2017 Change In Tax Rate Income Tax Expense Benefit TaxCutsAndJobsActOf2017ChangeInTaxRateIncomeTaxExpenseBenefit	-2700000	USD
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.021
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense EffectiveIncomeTaxRateReconciliationNondeductibleExpense	0.024
CY2020	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.039
CY2019	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	-0.008
CY2018	us-gaap	Effective Income Tax Rate Reconciliation Nondeductible Expense Other EffectiveIncomeTaxRateReconciliationNondeductibleExpenseOther	0.003
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.996
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.204
CY2018	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	-0.094
CY2020	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.996
CY2019	us-gaap	Effective Income Tax Rate Continuing Operations EffectiveIncomeTaxRateContinuingOperations	0.204
CY2020	abm	Unrecognized Tax Benefits Decrease Resultingfrom State True Ups UnrecognizedTaxBenefitsDecreaseResultingfromStateTrueUps	5700000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	53100000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	32700000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense Impairment Losses IncomeTaxReconciliationNondeductibleExpenseImpairmentLosses	163800000	USD
CY2020	abm	Effective Income Tax Rate Reconciliation Excluding Impairment Percent EffectiveIncomeTaxRateReconciliationExcludingImpairmentPercent	0.244
CY2020	abm	Increase Decreasein Tax Credits Work Opportunity Tax Credit IncreaseDecreaseinTaxCreditsWorkOpportunityTaxCredit	2300000	USD
CY2020	abm	Effective Income Tax Reconciliation Deduction Energy Efficiency Amount EffectiveIncomeTaxReconciliationDeductionEnergyEfficiencyAmount	2100000	USD
CY2020	abm	Effective Income Tax Rate Reconciliation Change In Tax Reserves Amount EffectiveIncomeTaxRateReconciliationChangeInTaxReservesAmount	1100000	USD
CY2019Q4	abm	Tax Benefits Lapseof Statuteof Limitations TaxBenefitsLapseofStatuteofLimitations	1800000	USD
CY2019	abm	Unrecognized Tax Benefits Decrease Resultingfrom State True Ups UnrecognizedTaxBenefitsDecreaseResultingfromStateTrueUps	1700000	USD
CY2019	abm	Unrecognized Tax Benefits Decrease Resultingfrom Federal True Ups UnrecognizedTaxBenefitsDecreaseResultingfromFederalTrueUps	1600000	USD
CY2019	abm	Increase Decreasein Tax Credits Work Opportunity Tax Credit IncreaseDecreaseinTaxCreditsWorkOpportunityTaxCredit	1300000	USD
CY2019	abm	Tax Benefits Lapseof Statuteof Limitations TaxBenefitsLapseofStatuteofLimitations	1300000	USD
CY2019	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Options Exercises In Period Total Intrinsic Value ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisesInPeriodTotalIntrinsicValue	1100000	USD
CY2019	abm	Unrecognized Tax Benefits Decrease Resultingfrom Researchand Development Credits UnrecognizedTaxBenefitsDecreaseResultingfromResearchandDevelopmentCredits	900000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Self Insurance DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance	74700000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Self Insurance DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsSelfInsurance	83600000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	28600000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefits	25600000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	8800000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Allowance For Doubtful Accounts DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsAllowanceForDoubtfulAccounts	5600000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Legal Settlements DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLegalSettlements	5000000.0	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Legal Settlements DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsLegalSettlements	3100000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther	1500000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Other DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsOther	1800000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other Comprehensive Loss DeferredTaxAssetsOtherComprehensiveLoss	2700000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other Comprehensive Loss DeferredTaxAssetsOtherComprehensiveLoss	500000	USD
CY2020Q4	us-gaap	Deferred Tax Assets State Taxes DeferredTaxAssetsStateTaxes	1400000	USD
CY2020Q4	us-gaap	Decrease In Unrecognized Tax Benefits Is Reasonably Possible DecreaseInUnrecognizedTaxBenefitsIsReasonablyPossible	600000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1500000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Expense UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestExpense	200000	USD
CY2020Q4	abm	Deferred Tax Assets Unrecognized Tax Benefits DeferredTaxAssetsUnrecognizedTaxBenefits	3200000	USD
CY2019Q4	us-gaap	Deferred Tax Assets State Taxes DeferredTaxAssetsStateTaxes	400000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	5900000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards State And Local DeferredTaxAssetsOperatingLossCarryforwardsStateAndLocal	11200000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	3700000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Credit Carryforwards DeferredTaxAssetsTaxCreditCarryforwards	6300000	USD
CY2019Q4	abm	Deferred Tax Assets Unrecognized Tax Benefits DeferredTaxAssetsUnrecognizedTaxBenefits	3000000.0	USD
CY2020Q4	abm	Deferred Tax Assets Deferred Payroll Taxes DeferredTaxAssetsDeferredPayrollTaxes	26900000	USD
CY2019Q4	abm	Deferred Tax Assets Deferred Payroll Taxes DeferredTaxAssetsDeferredPayrollTaxes	0	USD
CY2020Q4	abm	Deferred Tax Assets Operating Lease Liabilities DeferredTaxAssetsOperatingLeaseLiabilities	38200000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	200600000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	141200000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	4100000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	8400000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	196500000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	132800000	USD
CY2018	abm	Unrecognized Tax Benefits Interestand Penalties Benefit UnrecognizedTaxBenefitsInterestandPenaltiesBenefit	1000000.0	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties And Interest Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAndInterestAccrued	1200000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	1200000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	4800000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	159400000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Goodwill And Intangible Assets DeferredTaxLiabilitiesGoodwillAndIntangibleAssets	170600000	USD
CY2020Q4	abm	Deferred Tax Liabilities Operating Right Of Use Assets DeferredTaxLiabilitiesOperatingRightOfUseAssets	38200000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	8500000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	5200000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	207300000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	180600000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	10800000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	47700000	USD
CY2020Q4	us-gaap	Tax Credit Carryforward Amount TaxCreditCarryforwardAmount	4400000	USD
CY2019Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	8400000	USD
CY2020	abm	Operation Loss Carryforwards Valuation Allowance Other OperationLossCarryforwardsValuationAllowanceOther	-4300000	USD
CY2018Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	12000000.0	USD
CY2017Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	7700000	USD
CY2020	abm	Operation Loss Carryforwards Valuation Allowance Business Acquisition OperationLossCarryforwardsValuationAllowanceBusinessAcquisition	0	USD
CY2019	abm	Operation Loss Carryforwards Valuation Allowance Business Acquisition OperationLossCarryforwardsValuationAllowanceBusinessAcquisition	0	USD
CY2018	abm	Operation Loss Carryforwards Valuation Allowance Business Acquisition OperationLossCarryforwardsValuationAllowanceBusinessAcquisition	2400000	USD
CY2019	abm	Operation Loss Carryforwards Valuation Allowance Other OperationLossCarryforwardsValuationAllowanceOther	-3600000	USD
CY2018	abm	Operation Loss Carryforwards Valuation Allowance Other OperationLossCarryforwardsValuationAllowanceOther	1800000	USD
CY2020Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	4100000	USD
CY2019Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	8400000	USD
CY2018Q4	us-gaap	Operating Loss Carryforwards Valuation Allowance OperatingLossCarryforwardsValuationAllowance	12000000.0	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	35500000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	35300000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	35800000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	35300000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	35800000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	53400000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	2100000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	200000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1600000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	3600000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	0	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	9000000.0	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	3000000.0	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	3900000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	8700000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	500000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	300000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Settlements With Taxing Authorities UnrecognizedTaxBenefitsDecreasesResultingFromSettlementsWithTaxingAuthorities	100000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	35500000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	35300000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	35800000	USD
CY2020Q4	us-gaap	Number Of States In Which Entity Operates NumberOfStatesInWhichEntityOperates	50	state
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	5987600000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	6498600000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	6442200000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	95700000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	208300000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	53300000	USD
CY2018	us-gaap	Interest Expense InterestExpense	54100000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	138600000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	2200000	USD
CY2019	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	3000000.0	USD
CY2018	us-gaap	Income Loss From Equity Method Investments IncomeLossFromEquityMethodInvestments	3200000	USD
CY2020	us-gaap	Interest Expense InterestExpense	44600000	USD
CY2019	us-gaap	Interest Expense InterestExpense	51100000	USD
CY2020Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.78
CY2019Q3	us-gaap	Gross Profit GrossProfit	193900000	USD
CY2019Q4	us-gaap	Gross Profit GrossProfit	194700000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	160200000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	87700000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	96400000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	107400000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	112500000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	5987600000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	6498600000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	6442200000	USD
CY2020Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1612900000	USD
CY2020Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1496000000.0	USD
CY2020Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1394100000	USD
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2020Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.42
CY2020Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-2.05
CY2020Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.83
CY2020Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.78
CY2019Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	36500000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	13000000.0	USD
CY2019Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	29900000	USD
CY2019Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	48100000	USD
CY2019Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-100000	USD
CY2019Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-200000	USD
CY2020Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1484600000	USD
CY2020Q1	us-gaap	Gross Profit GrossProfit	179200000	USD
CY2020Q2	us-gaap	Gross Profit GrossProfit	189900000	USD
CY2020Q3	us-gaap	Gross Profit GrossProfit	219200000	USD
CY2020Q4	us-gaap	Gross Profit GrossProfit	242400000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	27900000	USD
CY2020Q2	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	-136800000	USD
CY2020Q3	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	56000000.0	USD
CY2020Q4	us-gaap	Income Loss From Continuing Operations IncomeLossFromContinuingOperations	53100000	USD
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	100000	USD
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	USD
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	USD
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	0	USD
CY2020Q1	us-gaap	Net Income Loss NetIncomeLoss	28000000.0	USD
CY2020Q2	us-gaap	Net Income Loss NetIncomeLoss	-136800000	USD
CY2020Q3	us-gaap	Net Income Loss NetIncomeLoss	56000000.0	USD
CY2019Q1	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1607900000	USD
CY2019Q2	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1594700000	USD
CY2019Q3	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1647900000	USD
CY2019Q4	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	1648000000.0	USD
CY2019Q1	us-gaap	Gross Profit GrossProfit	162000000.0	USD
CY2019Q2	us-gaap	Gross Profit GrossProfit	180500000	USD
CY2019Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	200000	USD
CY2020Q4	us-gaap	Net Income Loss NetIncomeLoss	53100000	USD
CY2020Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.42
CY2020Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	-2.05
CY2020Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.84
CY2020Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.79
CY2020Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2020Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.42
CY2020Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-2.05
CY2020Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.84
CY2020Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.79
CY2020Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.41
CY2020Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	-2.05
CY2020Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.83
CY2019Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Attributable To Reporting Entity IncomeLossFromDiscontinuedOperationsNetOfTaxAttributableToReportingEntity	-100000	USD
CY2019Q1	us-gaap	Net Income Loss NetIncomeLoss	13000000.0	USD
CY2019Q2	us-gaap	Net Income Loss NetIncomeLoss	29700000	USD
CY2019Q3	us-gaap	Net Income Loss NetIncomeLoss	36800000	USD
CY2019Q4	us-gaap	Net Income Loss NetIncomeLoss	47900000	USD
CY2019Q1	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.20
CY2019Q2	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.45
CY2019Q3	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.55
CY2019Q4	us-gaap	Income Loss From Continuing Operations Per Basic Share IncomeLossFromContinuingOperationsPerBasicShare	0.72
CY2019Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Basic Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerBasicShare	0
CY2019Q1	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.20
CY2019Q2	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.45
CY2019Q3	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.55
CY2019Q4	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	0.72
CY2019Q1	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.20
CY2019Q2	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.45
CY2019Q3	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.55
CY2019Q4	us-gaap	Income Loss From Continuing Operations Per Diluted Share IncomeLossFromContinuingOperationsPerDilutedShare	0.71
CY2019Q1	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019Q2	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019Q3	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019Q4	us-gaap	Income Loss From Discontinued Operations Net Of Tax Per Diluted Share IncomeLossFromDiscontinuedOperationsNetOfTaxPerDilutedShare	0
CY2019Q1	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.19
CY2019Q2	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.45
CY2019Q3	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.55
CY2019Q4	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	0.71
CY2020Q2	us-gaap	Asset Impairment Charges AssetImpairmentCharges	172800000	USD
CY2020Q2	abm	Asset Impairment Charges After Tax AssetImpairmentChargesAfterTax	170600000	USD
CY2020Q2	abm	Asset Impairment Charge Per Share Diluted AssetImpairmentChargePerShareDiluted	2.54

Files In Submission

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$ABM
ABM INDUSTRIES INC /DE/ Stock $abm

2020 Q4 Form 10-K Financial Statement

#000077149720000018 Filed on December 17, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ABM ABM INDUSTRIES INC /DE/ Stock $abm

2020 Q4 Form 10-K Financial Statement

#000077149720000018 Filed on December 17, 2020

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$ABM
ABM INDUSTRIES INC /DE/ Stock $abm