ABM Industries (ABM) 10-K 17 Dec 20 2020 FY Annual report Financial data

Cover Page

Cover Page - USD ($)	12 Months Ended
	Oct. 31, 2020	Dec. 15, 2020	Apr. 30, 2020
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Period End Date	Oct. 31, 2020
Current Fiscal Year End Date	--10-31
Document Transition Report	false
Entity File Number	1-8929
Entity Registrant Name	ABM INDUSTRIES INC
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	94-1369354
Entity Address, Address Line One	One Liberty Plaza
Entity Address, Address Line Two	7th Floor
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Address, Postal Zip Code	10006
City Area Code	212
Local Phone Number	297-0200
Title of 12(b) Security	Common Stock, $0.01 par value
Trading Symbol	ABM
Security Exchange Name	NYSE
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 2,277,588,018
Entity Common Stock, Shares Outstanding		66,758,670
Documents Incorporated by Reference	Certain parts of the registrant’s Definitive Proxy Statement relating to the registrant’s 2021 Annual Meeting of Stockholders are incorporated by reference into Part III of this Annual Report on Form 10-K.
Entity Central Index Key	0000771497
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	FY
Amendment Flag	false

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Current assets
Cash and cash equivalents	$ 394.2	$ 58.5
Trade accounts receivable, net of allowances of $35.5 and $22.4 at October 31, 2020 and 2019, respectively	854.2	1,013.2
Costs incurred in excess of amounts billed	52.2	72.6
Prepaid expenses	85.4	75.7
Other current assets	55.9	55.5
Total current assets	1,441.9	1,275.4
Other investments	11.1	14
Property, plant and equipment, net of accumulated depreciation of $241.3 and $199.5 at October 31, 2020 and 2019, respectively	133.7	150.3
Right-of-use assets	143.1
Other intangible assets, net of accumulated amortization of $343.8 and $309.0 at October 31, 2020 and 2019, respectively	239.7	297.2
Goodwill	1,671.4	1,835.4
Other noncurrent assets	136.1	120.3
Total assets	3,776.9	3,692.6
Current liabilities
Current portion of long-term debt, net	116.7	57.2
Trade accounts payable	273.3	280.7
Accrued compensation	187.6	189.3
Accrued taxes—other than income	45.5	63.6
Insurance claims	155.2	149.8
Income taxes payable	6.2	3.5
Current portion of lease liabilities	35
Other accrued liabilities	167.3	158.2
Total current liabilities	986.9	902.4
Long-term debt, net	603	744.2
Long-term lease liabilities	131.4
Deferred income tax liability, net	10.8	47.7
Noncurrent insurance claims	366.3	365.2
Other noncurrent liabilities	168.1	78.8
Noncurrent income taxes payable	10.1	12.2
Total liabilities	2,276.6	2,150.6
Commitments and contingencies
Stockholders’ Equity
Preferred stock, $0.01 par value; 500,000 shares authorized; none issued	0	0
Common stock, $0.01 par value; 100,000,000 shares authorized; 66,748,157 and 66,571,427 shares issued and outstanding at October 31, 2020 and 2019, respectively	0.7	0.7
Additional paid-in capital	724.1	708.9
Accumulated other comprehensive loss, net of taxes	(30.8)	(23.9)
Retained earnings	806.4	856.3
Total stockholders’ equity	1,500.3	1,542
Total liabilities and stockholders’ equity	$ 3,776.9	$ 3,692.6

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Statement of Financial Position [Abstract]
Trade accounts receivable, allowance	$ 35.5	$ 22.4
Property, plant and equipment, accumulated depreciation	241.3	199.5
Other intangible assets, accumulated amortization	$ 343.8	$ 309
Preferred stock, par value (usd per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Common stock, par value (usd per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares issued (in shares)	66,748,157	66,571,427
Common stock, shares outstanding (in shares)	66,748,157	66,571,427

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income - USD ($) shares in Millions, $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Income Statement [Abstract]
Revenues	$ 5,987.6	$ 6,498.6	$ 6,442.2
Operating expenses	5,157	5,767.5	5,747.4
Selling, general and administrative expenses	506.1	452.9	438
Restructuring and related expenses	7.6	11.2	25.7
Amortization of intangible assets	48.4	58.5	66
Impairment loss	172.8	0	26.5
Operating profit	95.7	208.3	138.6
Income from unconsolidated affiliates	2.2	3	3.2
Interest expense	(44.6)	(51.1)	(54.1)
Income from continuing operations before income taxes	53.3	160.2	87.7
Income tax (provision) benefit	(53.1)	(32.7)	8.2
Income from continuing operations	0.2	127.5	95.9
Income (loss) from discontinued operations, net of taxes	0.1	(0.1)	1.8
Net income	0.3	127.4	97.8
Other comprehensive (loss) income
Interest rate swaps	(7.6)	(22.4)	21.9
Foreign currency translation and other	(1.8)	1.6	(4.7)
Income tax benefit (provision)	2.4	5.9	(5.9)
Comprehensive (loss) income	$ (6.6)	$ 112.5	$ 109
Net income per common share — Basic
Income from continuing operations (usd per share)	$ 0	$ 1.92	$ 1.45
Income from discontinued operations (usd per share)	0	0	0.03
Net income (usd per share)	0	1.91	1.48
Net income per common share — Diluted
Income from continuing operations (usd per share)	0	1.91	1.45
Income from discontinued operations (usd per share)	0	0	0.03
Net income (usd per share)	$ 0	$ 1.90	$ 1.47
Weighted-average common and common equivalent shares outstanding
Basic (in shares)	66.9	66.6	66.1
Diluted (in shares)	67.3	66.9	66.4

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Millions	Total	Common Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Loss, Net of Taxes	Retained Earnings	Retained EarningsCumulative Effect, Period of Adoption, Adjustment
Balance, beginning of year (in shares) at Oct. 31, 2017		65,500,000
Balance, beginning of year at Oct. 31, 2017		$ 0.7	$ 675.2	$ (20.3)	$ 720.1
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		500,000
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans		$ 0	(0.4)
Share-based compensation expense			17
Repurchase of common stock (in shares)	0	0
Repurchase of common stock		$ 0	0
Other comprehensive (loss) income				11.3
Net income	$ 97.8				97.8
Dividends
Common stock ($0.740, $0.720, and $0.700 per share)					(46)
Common stock, dividends (usd per share)	$ 0.700
Stock issued under share-based compensation plans					(0.6)
Balance, end of year (in shares) at Oct. 31, 2018		66,000,000
Balance, end of year at Oct. 31, 2018	$ 1,454.6	$ 0.7	691.8	(9)	771.2
Dividends
Accounting Standards Update [Extensible List]	us-gaap:AccountingStandardsUpdate201409Member
Stock issued under employee stock purchase and share-based compensation plans (in shares)		600,000
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans		$ 0	(0.3)
Share-based compensation expense			17.5
Repurchase of common stock (in shares)	0	0
Repurchase of common stock		$ 0	0
Other comprehensive (loss) income				(14.9)
Net income	$ 127.4				127.4
Common stock ($0.740, $0.720, and $0.700 per share)					(47.7)
Common stock, dividends (usd per share)	$ 0.720
Stock issued under share-based compensation plans					(1)
Balance, end of year (in shares) at Oct. 31, 2019		66,600,000
Balance, end of year at Oct. 31, 2019	$ 1,542	$ 0.7	708.9	(23.9)	856.3
Balance, beginning of year at Jul. 31, 2019						$ 6.5
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	47.9
Balance, end of year (in shares) at Oct. 31, 2019		66,600,000
Balance, end of year at Oct. 31, 2019	$ 1,542	$ 0.7	708.9	(23.9)	856.3
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock issued under employee stock purchase and share-based compensation plans (in shares)		300,000
Stock issued (taxes withheld) under employee stock purchase and share-based compensation plans		$ 0	0
Share-based compensation expense			20.3
Repurchase of common stock (in shares)	(200,000)	(200,000)
Repurchase of common stock	$ (5.1)	$ 0	(5.1)
Other comprehensive (loss) income				(6.9)
Net income	$ 0.3				0.3
Dividends
Common stock ($0.740, $0.720, and $0.700 per share)					(49.3)
Common stock, dividends (usd per share)	$ 0.740
Stock issued under share-based compensation plans					(0.9)
Balance, end of year (in shares) at Oct. 31, 2020		66,700,000
Balance, end of year at Oct. 31, 2020	$ 1,500.3	$ 0.7	$ 724.1	$ (30.8)	$ 806.4

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Cash flows from operating activities
Net income	$ 0.3	$ 127.4	$ 97.8
(Income) loss from discontinued operations, net of taxes	(0.1)	0.1	(1.8)
Income from continuing operations	0.2	127.5	95.9
Adjustments to Reconcile Net Income (Loss) to Cash Provided by (Used in) Operating Activities [Abstract]
Depreciation and amortization	96.4	107.4	112.5
Proceeds from termination of interest rate swaps	0	0	25.9
Impairment loss	172.8	0	26.5
Deferred income taxes	(36.6)	9.7	(23.7)
Share-based compensation expense	20.3	17.5	17
Provision for bad debt	19.6	6.7	6.4
Amortization of accumulated other comprehensive gain on interest rate swaps	(6.7)	(5.7)	(2.5)
Discount accretion on insurance claims	0.8	0.8	0.8
Loss (gain) on sale of assets	2.1	(0.6)	0.5
Reserves on other assets	17.6	0	0
Income from unconsolidated affiliates	(2.2)	(3)	(3.2)
Distributions from unconsolidated affiliates	0.1	5.4	1.9
Changes in operating assets and liabilities, net of effects of acquisitions
Trade accounts receivable and costs incurred in excess of amounts billed	141.4	(78.3)	16
Prepaid expenses and other current assets	(15.5)	(13.2)	2.4
Right-of-use assets	24.4
Other noncurrent assets	(10.4)	4.5	11.3
Trade accounts payable and other accrued liabilities	(53.5)	85.8	(1.5)
Long-term lease liabilities	(22.9)
Insurance claims	5.7	3.9	13.9
Income taxes payable	7.6	3.2	0.7
Other noncurrent liabilities	96.2	(8.7)	(1.2)
Total adjustments	457.2	135.3	203.7
Net cash provided by operating activities of continuing operations	457.4	262.8	299.7
Net cash provided by (used in) operating activities of discontinued operations	0.1	(0.1)	21.2
Net cash provided by operating activities	457.5	262.7	320.9
Cash flows from investing activities
Additions to property, plant and equipment	(38)	(59.6)	(50.9)
Proceeds from sale of assets	5.5	1.3	2.3
Adjustments to sale of business	0	0	(1.9)
Proceeds from redemption of auction rate security	5	0	2.9
Investments in unconsolidated affiliates	0	0	(0.4)
Net cash used in investing activities	(27.5)	(58.3)	(48.1)
Cash flows from financing activities
Taxes withheld from issuance of share-based compensation awards, net	(0.9)	(1.3)	(1)
Repurchases of common stock	(5.1)	0	0
Dividends paid	(49.3)	(47.7)	(46)
Deferred financing costs paid	(4.4)	0	(0.1)
Borrowings from credit facility	1,058.5	1,755.9	1,184.2
Repayment of borrowings from credit facility	(1,141.6)	(1,896.5)	(1,426.4)
Changes in book cash overdrafts	41.2	(0.2)	(8.5)
Financing of energy savings performance contracts	11.1	8.1	5.4
Repayment of finance lease obligations	(3.4)	(3.1)	(3.3)
Net cash used in financing activities	(94.1)	(184.8)	(295.8)
Effect of exchange rate changes on cash and cash equivalents	(0.2)	(0.2)	(0.7)
Net increase (decrease) in cash and cash equivalents	335.7	19.4	(23.7)
Cash and cash equivalents at beginning of year	58.5	39.1	62.8
Cash and cash equivalents at end of year	394.2	58.5	39.1
Supplemental cash flow information
Income tax payments (refunds), net	82.2	20.6	(1)
Interest paid on credit facility	$ 32.9	$ 39.9	$ 49.6

Consolidated Statements of St_2

Consolidated Statements of Stockholders' Equity (Parenthetical) - $ / shares	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Statement of Stockholders' Equity [Abstract]
Common stock, dividends (usd per share)	$ 0.740	$ 0.720	$ 0.700

The Company and Nature of Opera

The Company and Nature of Operations	12 Months Ended
	Oct. 31, 2020
Organization, Consolidation and Presentation of Financial Statements [Abstract]
The Company and Nature of Operations	THE COMPANY AND NATURE OF OPERATIONS ABM is a leading provider of integrated facility services with a mission to make a difference, every person, every day . We are organized into four industry groups and one Technical Solutions segment: 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.

Basis of Presentation and Signi

Basis of Presentation and Significant Accounting Policies	12 Months Ended
	Oct. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation and Significant Accounting Policies	BASIS OF PRESENTATION AND SIGNIFICANT ACCOUNTING POLICIES Basis of Presentation and Principles of Consolidation The Financial Statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the SEC, specifically Regulation S-X and the instructions to Form 10-K. Unless otherwise indicated, all references to years are to our fiscal year, which ends on October 31. The Financial Statements include the accounts of ABM and all of our consolidated subsidiaries. We account for ABM’s investments in unconsolidated affiliates under the equity method of accounting. We include the results of acquired businesses in the Consolidated Statements of Comprehensive (Loss) Income from their respective acquisition dates. All intercompany accounts and transactions have been eliminated in consolidation. 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. We round amounts in the Financial Statements to millions and calculate all percentages and per-share data from the underlying whole-dollar amounts. Thus, certain amounts may not foot, crossfoot, or recalculate based on reported numbers due to rounding. Impact of the Pandemic A novel strain of COVID-19 has resulted in a worldwide health Pandemic. To date, the Pandemic has surfaced in nearly all regions around the world and resulted in business slowdowns and shutdowns, as well as global travel restrictions. In these Financial Statements and related disclosures we have assessed the current impact of the Pandemic on our financial condition, results of operations, and cash flows as well as on our estimates, forecasts, and accounting policies. We have made additional disclosures of these assessments as necessary. Given the unprecedented nature of this situation, we cannot reasonably estimate the full impact the Pandemic will have on our financial condition, results of operations, or cash flows in the foreseeable future. The ultimate impact of the Pandemic on our company is highly uncertain and will depend on future developments, and such impacts could exist for an extended period of time, even after the Pandemic subsides. The Pandemic continues to create a dynamic client environment, and we are working diligently to ensure our clients’ changing staffing and service needs are met while actively managing direct labor and related personnel costs, including furloughs or reduced hours for certain service employees in markets significantly impacted by business slowdowns and shutdowns. In addition, during the second and third quarters of 2020, we took several human capital management actions to align our organization operationally and help mitigate the financial impact of the Pandemic on our business, one of which included temporary furloughs for certain staff and management employees. To continue supporting furloughed staff and management employees during the Pandemic, we paid 100% of health insurance premiums during the furlough period for those enrolled in health benefit plans. Most of the furloughed staff and management employees returned to work effective August 1, 2020, and we have not accrued any additional expenses associated with these employees as of October 31, 2020. In response to the Pandemic, Congress enacted the CARES Act on March 27, 2020. The CARES Act provides various stimulus measures, including several income tax and payroll tax provisions. Among the payroll tax provisions is the creation of a refundable credit for employee retention and the deferral of certain payroll tax remittances through December 31, 2020, to future years (with 50% of the deferred amount due by December 31, 2021, and the remaining 50% due by December 31, 2022). We evaluated the impact of business tax provisions in the CARES Act. The impact of the income tax provisions was not material. The impact of the payroll tax provisions was the deferral of approximately $101 million of payroll tax as of October 31, 2020. Refer to additional discussion regarding the Pandemic and the impact on our business throughout this document, including Note 7, “Fair Value of Financial Instruments,” Note 9, “Goodwill and Other Intangible Assets,” and Note 11, “Credit Facility.” Cash and Cash Equivalents We consider all highly liquid securities with an original maturity of three months or less to be cash and cash equivalents. As part of our cash management system, we use “zero balance” accounts to fund our disbursements. Under this system, at the end of each day the bank balance is zero, while the book balance is usually a negative amount due to reconciling items, such as outstanding checks. We report the changes in these book cash overdrafts as cash flows from financing activities. Trade Accounts Receivable and Costs Incurred in Excess of Amounts Billed Trade accounts receivable arise from services provided to our clients and are usually due and payable on varying terms from receipt of the invoice to net ninety days, with the exception of certain Technical Solutions project receivables that may have longer collection periods. These receivables are recorded at the invoiced amount and normally do not bear interest. In addition, our trade accounts receivable include unbilled receivables, such as invoices for services that have been provided but are not yet billed. Costs incurred in excess of amounts billed arise from Technical Solutions project contracts that typically provide for a schedule of billings or invoices to the client based on our performance to date of specific tasks inherent in the fulfillment of our performance obligation(s). The schedules for such billings usually do not precisely match the schedule on which costs are incurred. As a result, revenues generally differ from amounts that can be billed or invoiced to the client at any point during the contract. Allowance for Doubtful Accounts We determine the allowance for doubtful accounts based on historical write-offs, known or expected trends, and the identification of specific balances deemed uncollectible. For the specifically identified balances, we establish the reserve upon the earlier of a client’s inability to meet its financial obligations or after a period of twelve months, unless our management believes such amounts will ultimately be collectible. Sales Allowance In connection with our service contracts, we periodically issue credit memos to our clients that are recorded as a reduction in revenues and an increase to the allowance for billing adjustments. These credits can result from client vacancy discounts, job cancellations, property damage, and other items. We estimate our potential future losses on these client receivables based on an analysis of the historical rate of sales adjustments (credit memos, net of re-bills) and known or expected trends. Other Current Assets At October 31, 2020 and 2019, other current assets primarily consisted of other receivables, short-term insurance recoverables, and capitalized commissions. Other Investments At October 31, 2020 and 2019, other investments primarily consisted of investments in unconsolidated affiliates, as well as auction rate securities at October 31, 2019. Investments in Unconsolidated Affiliates We own non-controlling interests (generally 20% to 50%) in certain affiliated entities that predominantly provide facility solutions to governmental and commercial clients, primarily in the United States and the Middle East. We account for such investments under the equity method of accounting. We evaluate our equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may not be recoverable. An impairment loss is recognized to the extent that the estimated fair value of the investment is less than its carrying amount and we determine that the impairment is other-than-temporary. At October 31, 2020, 2019, and 2018, our investments in unconsolidated affiliates were $11.0 million, $8.9 million, and $11.3 million, respectively. We did not recognize any impairment charges on these investments in 2020, 2019, or 2018. Investments in Auction Rate Securities Our investments in auction rate securities are classified as available-for-sale. Accordingly, auction rate securities are presented at fair value with unrealized gains and losses recorded in accumulated other comprehensive (loss) income, net of tax es (“AOCL”). On a quarterly basis, we analyze all auction rate securities that have unrealized losses for impairment consideration and assess the intent to sell such securities. If such intent exists, impaired securities are considered other-than-temporarily impaired and we recognize the entire difference between the auction rate security’s amortized cost and its fair value in earnings. We also consider if we may be required to sell the securities prior to the recovery of amortized cost, which may trigger an impairment charge. If these securities are considered impaired, we assess whether the amortized costs of the securities can be recovered by reviewing several factors, including credit risks associated with the issuer. If we do not expect to recover the entire amortized cost of the security, we consider the security to be other-than-temporarily impaired and record the difference between the security’s amortized costs and its recoverable amount in earnings and the difference between the security’s amortized cost and fair value in AOCL . During the first quarter of 2020, our last remaining auction rate security was called by the issuer, and we received proceeds for the fair value of the debt instrument of $5.0 million. As of October 31, 2020, we had no investments in auction rate securities. Property, Plant and Equipment We record property, plant and equipment at cost. Repairs and maintenance expenditures are expensed as incurred. In contrast, we capitalize major renewals or replacements that substantially extend the useful life of an asset. We determine depreciation for financial reporting purposes using the straight-line method over the following estimated useful lives: Category Years Computer equipment and software 3–5 Machinery and other equipment 3–5 Transportation equipment 1.5–10 Buildings 10–40 Furniture and fixtures 5 In addition, we depreciate assets under finance leases and leasehold improvements over the shorter of their estimated useful lives or the remaining lease term. Upon retirement or sale of an asset, we remove the cost and accumulated depreciation from our Consolidated Balance Sheets. When applicable, we record corresponding gains or losses within the accompanying Consolidated Statements of Comprehensive (Loss) Income. Leases We enter into various noncancelable lease agreements for office space, parking facilities, warehouses, vehicles, and equipment used in the normal course of business. We determine if an arrangement is a lease at inception and begin recording lease activity at the commencement date, which is generally the date in which we take possession of or control the physical use of the asset. Right-of-use (“ROU”) assets and lease liabilities are recognized based on the present value of lease payments over the lease term with lease expense recognized on a straight-line basis. We use our incremental borrowing rate to determine the present value of future lease payments unless the implicit rate in a lease is readily determinable. Our incremental borrowing rate is the rate of interest we would have to pay to borrow on a collateralized basis over a similar term at an amount equal to the lease payments in a similar economic environment. This incremental borrowing rate is applied to the minimum lease payments within each lease agreement to determine the amounts of our ROU assets and lease liabilities. Our incremental borrowing rate as of November 1, 2019, was utilized for the initial measurement of operating lease liabilities upon adoption of Topic 842, as described below in “Recently Adopted Accounting Standards.” Our lease terms range from 1 to 30 years. Some leases include one or more options to renew, with renewal terms that can extend the lease term. We typically include options to extend the lease in a lease term when it is reasonably certain that we will exercise that option and when doing so is at our sole discretion. Certain equipment and vehicle leases may also include options to purchase the leased property. The depreciable life of assets and leasehold improvements are limited by the expected lease term unless there is a transfer of title or purchase option reasonably certain of exercise. Typically, if we decide to cancel or terminate a lease before the end of its term, we would owe the lessor the remaining lease payments under the term of such lease. Our lease agreements generally do not contain any material residual value guarantees or material restrictive covenants. We may rent or sublease certain real estate assets that we no longer use to third parties. Lease agreements may contain rent escalation clauses, rent holidays, or certain landlord incentives, including tenant improvement allowances. Prior to November 1, 2019, we recognized lease expense related to operating leases on a straight-line basis over the terms of the leases and, accordingly, recorded the difference between cash rent payments and recognition of rent expense as a deferred rent liability or prepaid rent. Landlord-funded leasehold improvements were also recorded as deferred rent liabilities and were amortized as a reduction of rent expense over the noncancelable term of the related operating lease. The ROU assets recognized upon adoption of Topic 842 include: cumulative prepaid or accrued rent on the adoption date, unamortized lease incentives, and unamortized initial direct costs initially recognized prior to adoption of Topic 842. Following adoption of Topic 842, ROU assets include amounts for scheduled rent increases and are reduced by lease incentive amounts. Certain of our lease agreements include variable rent payments, consisting primarily of rental payments adjusted periodically for inflation and amounts paid to the lessor based on cost or consumption, such as maintenance and utilities . These costs are expensed as incurred. Certain of our parking arrangements also contain variable rent payments that are a percentage of parking services revenue based on contractual levels. We record contingent rent as it becomes probable that specified targets will be met. Vari able rent lease components are not included in the lease liability. Service concession arrangements within the scope of ASU No. 2017-10, Service Concession Arrangements (Topic 853) : Determining the Customer of the Operation Services , are excluded from the scope of Topic 842. Lease costs associated with these arrangements are recorded as a reduction of revenues. See Note 3, “Revenues,” for further discussion. Goodwill and Other Intangible Assets Goodwill represents the excess purchase price of acquired businesses over the fair value of the assets acquired and liabilities assumed. We have elected to make the first day of our fourth quarter, August 1st, the annual impairment assessment date for goodwill. However, we could be required to evaluate the recoverability of goodwill more often if impairment indicators exist. Goodwill is tested for impairment at a “reporting unit” level by performing either a qualitative evaluation or a quantitative test. The qualitative evaluation is an assessment of factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. We may elect not to perform the qualitative assessment for some or all reporting units and instead perform a quantitative test under which we estimate the fair value using a weighting of fair values derived from an income approach and a market approach. The discounted estimates of future cash flows include significant management assumptions, such as revenue growth rates, operating margins, weighted average cost of capital, and future economic and market conditions. Other intangible assets primarily consist of acquired customer contracts and relationships that are amortized using the sum-of-the-years’-digits method over their useful lives, consistent with the estimated useful life considerations used in the determination of their fair values. This accelerated method of amortization reflects the pattern in which the economic benefits from the intangible assets of customer contracts and relationships are expected to be realized. We amortize other non-customer acquired intangibles using a straight-line method of amortization. We evaluate other intangible assets, as well as our long-lived assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. When this occurs, a recoverability test is performed that compares the projected undiscounted cash flows from the use and eventual disposition of an asset or asset group to its carrying amount. If the projected undiscounted cash flows are less than the carrying amount, we calculate an impairment loss. The impairment loss calculation compares the fair value, which is based on projected discounted cash flows, to the carrying value. See Note 9, “Goodwill and Other Intangible Assets,” for further information on goodwill, other intangible assets, and impairment charges. Other Noncurrent Assets At October 31, 2020 and 2019, other noncurrent assets primarily consisted of long-term insurance recoverables, deferred charges, insurance and other long-term deposits, ESPC receivables, capitalized commissions, and prepayments to carriers for future insurance claims. Federal Energy Savings Performance Contract Receivables As part of our Technical Solutions business, we enter into ESPCs with the federal government pursuant to which we agree to develop, design, engineer, and construct a project and to guarantee that the project will satisfy agreed-upon performance standards. ESPC receivables represent the amount to be paid by various federal government agencies for work we have satisfactorily performed under specific ESPCs. We assign certain of our rights to receive those payments to unaffiliated third parties that provide construction financing, which we record as a liability, for such contracts. This construction financing is recorded as cash flows from financing activities, while the use of the cash received to pay project costs under these arrangements is classified as operating cash flows. The ESPC receivable is recognized as revenue as each project is constructed. Upon completion and acceptance of the project by the government and upon satisfaction of true sale criteria, the assigned ESPC receivable from the government and corresponding ESPC liability are eliminated from our consolidated financial statements. Fair Value of Financial Instruments Fair value is the price we would receive to sell an asset or pay to transfer a liability in an orderly transaction with a market participant at the measurement date. In the absence of active markets for identical assets or liabilities, such measurements involve developing assumptions based on market observable data and, in the absence of such data, internal information that is consistent with what market participants would use in a hypothetical transaction that occurs at the measurement date. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. Preference is given to observable inputs. These two types of inputs create the following fair value hierarchy: Level 1 – Quoted prices for identical instruments in active markets; Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable; and Level 3 – Significant inputs to the valuation model are unobservable. We evaluate assets and liabilities subject to fair value measurements on a recurring and non-recurring basis to determine the appropriate level at which to classify them for each reporting period. Some non-financial assets are measured at fair value on a non-recurring basis only in certain circumstances, including the event of impairment. See Note 7, “Fair Value of Financial Instruments,” for the fair value hierarchy table and for details on how we measure fair value for our assets and liabilities. Insurance Reserves We use a combination of insured and self-insurance programs to cover workers’ compensation, general liability, automobile liability, property damage, and other insurable risks. Insurance claim liabilities represent our estimate of retained risks without regard to insurance coverage. We retain a substantial portion of the risk related to certain workers’ compensation and medical claims. Liabilities associated with these losses include estimates of both filed claims and IBNR Claims. With the assistance of third-party actuaries, we periodically review our estimate of ultimate losses for IBNR Claims and adjust our required self-insurance reserves as appropriate. As part of this evaluation, we review the status of existing and new claim reserves as established by third-party claims administrators. The third-party claims administrators establish the case reserves based upon known factors related to the type and severity of the claims, demographic factors, legislative matters, and case law, as appropriate. We compare actual trends to expected trends and monitor claims developments. The specific case reserves estimated by the third-party administrators are provided to an actuary who assists us in projecting an actuarial estimate of the overall ultimate losses for our self-insured or high deductible programs, which includes the case reserves plus an actuarial estimate of reserves required for additional developments, such as IBNR Claims. We utilize the results of actuarial studies to estimate our insurance rates and insurance reserves for future periods and to adjust reserves, if appropriate, for prior years. In general, our insurance reserves are recorded on an undiscounted basis. We allocate current-year insurance expense to our operating segments based upon their underlying exposures, while actuarial adjustments related to prior year claims are recorded within Corporate expenses. We classify claims as current or long-term based on the expected settlement date. Estimated insurance recoveries related to recorded liabilities are reflected as assets in our Consolidated Balance Sheets when we believe the receipt of such amounts is probable. Other Accrued Liabilities At October 31, 2020 and 2019, other accrued liabilities primarily consisted of notes payable, other accrued expenses, legal fees and settlements, contract liabilities (which include deferred revenue and progress billings in excess of costs), employee benefits, unclaimed property, severance, insurance claims, rent payable, interest, and current finance leases. Other Noncurrent Liabilities At October 31, 2020 and 2019, other noncurrent liabilities primarily consisted of deferred payroll taxes, deferred rent, warranty reserves, ESPC liabilities, retirement plan liabilities, deferred compensation, and long-term finance leases. Revenue Recognition Beginning in fiscal 2019, we adopted ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , and ASU 2017-10, Service Concession Arrangements (Topic 853) : Determining the Customer of the Operation Services . Prior period amounts have not been restated and continue to be reported in accordance with our historical accounting policies. Our revenue recognition policies under Topic 606 and Topic 853 are described in the following paragraphs, and references to our prior period policies are included below where they are substantially different. See Note 3, “Revenues,” for further information on our revenues. Contracts with Customers We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collectability of consideration is probable. Once a contract is identified, we evaluate whether it is a combined or single contract and whether it should be accounted for as more than one performance obligation. Generally, most of our contracts are cancelable by either party without a substantive penalty, and the majority of our contracts have a notification period of 30 to 60 days. If a contract includes a cancellation clause, the remaining contract term is limited to the required termination notice period. At contract inception, we assess the services promised to our customers and identify a performance obligation for each promise to transfer to the customer a service, or a bundle of services, that is distinct. To identify the performance obligation, we consider all of our services promised in the contract, regardless of whether they are explicitly stated or are implied by customary business practices. The majority of our contracts contain multiple promises that represent an integrated bundle of services comprised of activities that may vary over time; however, these activities fulfill a single integrated performance obligation since we perform a continuous service that is substantially the same and has the same pattern of transfer to the customer. Our performance obligations are primarily satisfied over time as we provide the related services. We allocate the contract transaction price to this single performance obligation and recognize revenue as the services are performed, as further described in “Contract Types” below. Certain arrangements involve variable consideration (primarily per transaction fees, reimbursable expenses, and sales-based royalties). We do not estimate the variable consideration for these arrangements; rather, we recognize these variable fees in the period they are earned. Some of our contracts, often related to Airline Services, may also include performance incentives based on variable performance measures that are ascertained exclusively by future performance and therefore cannot be estimated at contract inception and are recognized as revenue once known and mutually agreed upon. We include estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of our anticipated performance and all information (historical, current, and forecasted) that is reasonably available to us. We primarily account for our performance obligations under the series guidance, using the as-invoiced practical expedient when applicable. We apply the as-invoiced practical expedient to record revenue as the services are provided, given the nature of the services provided and the frequency of billing under the customer contracts. Under this practical expedient, we recognize revenue in an amount that corresponds directly with the value to the customer of our performance completed to date and for which we have the right to invoice the customer. We typically bill customers on a monthly basis and have the right to consideration from customers in an amount that corresponds directly with the performance obligation satisfied to date. The time between completion of the performance obligation and collection of cash is generally 30 to 60 days. Sales-based taxes are excluded from revenue. Contracts generally can be modified to account for changes in specifications and requirements. We consider contract modifications to exist when the modification either changes the consideration, creates new performance obligations, or changes the existing scope of the contract and related performance obligations. Historically, contract modifications have been for services that are not distinct from the existing contract, since we are providing a bundle of services that are highly interrelated, and are therefore treated as if they were part of that existing contract. Such modifications are generally accounted for prospectively as part of the existing contract. Contract Types We have arrangements under various contract types, as described below. Monthly Fixed-Price Monthly fixed-price arrangements are contracts in which the client agrees to pay a fixed fee every month over a specified contract term. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Square-Foot Square-foot arrangements are contracts in which the client agrees to pay a fixed fee every month based on the actual square footage serviced over a specified contract term. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Cost-Plus Cost-plus arrangements are contracts in which the clients reimburse us for the agreed-upon amount of wages and benefits, payroll taxes, insurance charges, and other expenses associated with the contracted work, plus a profit margin. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Work Orders Work orders generally consist of supplemental services requested by clients outside of the standard service specification and include cleanup after tenant moves, construction cleanup, flood cleanup, and snow removal. The nature of these short-term contracts involves performing one-off type services, and revenue is recognized at the agreed-upon contractual amount over time as the services are provided because the customer simultaneously receives and consumes the benefits of the services as they are performed. Transaction-Price Transaction-price contracts are arrangements in which customers are billed a fixed price for each transaction performed on a monthly basis (e.g., wheelchair passengers served, airplane cabins cleaned). We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Hourly Hourly arrangements are contracts in which the client is billed a fixed hourly rate for each labor hour provided. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Management Reimbursement Under management reimbursement arrangements we manage a parking facility for a management fee and pass through the revenue and expenses associated with the facility to the owner. We measure progress toward satisfaction of the performance obligation over time as the services are provided. Under these contracts we recognize both revenues and expenses, in equal amounts, that are directly reimbursed from the property owner for operating expenses, as such expenses are incurred. Such revenues do not include gross customer collections at the managed locations because they belong to the property owners. We have determined we are the principal in these transactions, because the nature of our performance obligation is for us to provide the services on behalf of the customer and we have control of the promised services be

Revenues

Revenues	12 Months Ended
	Oct. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenues	REVENUES Disaggregation of Revenues We generate revenues under several types of contracts, which are further described in Note 2, “Basis of Presentation and Significant Accounting Policies.” Generally, the type of contract is determined by the nature of the services provided by each of our major service lines throughout our reportable segments; therefore, we disaggregate revenues from contracts with customers into major service lines. We have determined that disaggregating revenues into these categories best depicts how the nature, amount, timing, and uncertainty of revenues and cash flows are affected by economic factors. Our reportable segments are B&I, T&M, Education, Aviation, and Technical Solutions, as described in Note 17, “Segment and Geographic Information.” Year Ended October 31, 2020 (in millions) B&I T&M Education Aviation Technical Solutions Total Major Service Line Janitorial (1) $ 2,420.4 $ 770.9 $ 716.5 $ 121.2 $ — $ 4,029.0 Parking (2) 362.8 33.5 1.8 255.9 — 654.0 Facility Services (3) 374.1 151.6 90.5 31.6 — 647.9 Building & Energy Solutions (4) — — — — 506.6 506.6 Airline Services (5) 0.4 — — 272.2 — 272.6 $ 3,157.8 $ 956.0 $ 808.8 $ 680.9 $ 506.6 $ 6,110.0 Elimination of inter-segment revenues (122.4) Total $ 5,987.6 Year Ended October 31, 2019 (in millions) B&I T&M Education Aviation Technical Solutions Total Major Service Line Janitorial (1) $ 2,316.1 $ 739.7 $ 756.3 $ 125.8 $ — $ 3,937.9 Parking (2) 511.5 25.9 3.1 335.3 — 875.8 Facility Services (3) 423.1 151.4 88.0 72.1 — 734.6 Building & Energy Solutions (4) — — — — 593.2 593.2 Airline Services (5) 0.6 0.1 — 484.1 — 484.8 $ 3,251.4 $ 917.0 $ 847.4 $ 1,017.3 $ 593.2 $ 6,626.3 Elimination of inter-segment revenues (127.7) Total $ 6,498.6 (1) Janitorial arrangements provide a wide range of essential cleaning services for commercial office buildings, airports and other transportation centers, educational institutions, government buildings, health facilities, industrial buildings, retail stores, and stadiums and arenas. These arrangements are often structured as monthly fixed-price, square-foot, cost-plus, and work order contracts. (2) Parking arrangements provide parking and transportation services for clients at various locations, including airports and other transportation centers, commercial office buildings, educational institutions, health facilities, hotels, and stadiums and arenas. These arrangements are structured as management reimbursement, leased location, and allowance contracts. Certain of these arrangements are considered service concession agreements and are accounted for under the guidance of Topic 853; accordingly, rent expense related to these arrangements is recorded as a reduction of the related parking service revenues. (3) Facility Services arrangements provide onsite mechanical engineering and technical services and solutions relating to a broad range of facilities and infrastructure systems that are designed to extend the useful life of facility fixed assets, improve equipment operating efficiencies, reduce energy consumption, lower overall operational costs for clients, and enhance the sustainability of client locations. These arrangements are generally structured as monthly fixed-price, cost-plus, and work order contracts. (4) Building & Energy Solutions arrangements provide custom energy solutions, electrical, HVAC, lighting, and other general maintenance and repair services for clients in the public and private sectors and are generally structured as Energy Savings and Fixed-Price Repair and Refurbishment contracts. We also franchise certain operations under franchise agreements relating to our Linc Network and TEGG brands pursuant to franchise contracts. (5) Airline Services arrangements support airlines and airports with services such as passenger assistance, catering logistics, and airplane cabin maintenance. These arrangements are often structured as monthly fixed-price, cost-plus, transaction price, and hourly contracts. Remaining Performance Obligations At October 31, 2020, performance obligations that were unsatisfied or partially unsatisfied for which we expect to recognize revenue totaled $266.3 million. We expect to recognize revenue on approximately 61% of the remaining performance obligations over the next 12 months, with the remainder recognized thereafter, based on our estimates of project timing. These amounts exclude variable consideration primarily related to: (i) contracts where we have determined that the contract consists of a series of distinct service periods and revenues are based on future performance that cannot be estimated at contract inception; (ii) parking contracts where we and the customer share the gross revenues or operating profit for the location; and (iii) contracts where transaction prices include performance incentives that are based on future performance and therefore cannot be estimated at contract inception. We apply the practical expedient that permits exclusion of information about the remaining performance obligations with original expected durations of one year or less. Contract Balances The following tables present the balances in our contract assets and contract liabilities: (in millions) October 31, 2020 October 31, 2019 Contract assets Billed trade receivables (1) $ 835.8 $ 978.7 Unbilled trade receivables (1) 53.9 56.9 Costs incurred in excess of amounts billed (2) 52.2 72.6 Capitalized commissions (3) 25.2 21.8 (1) Included in trade accounts receivable, net, on the Consolidated Balance Sheets. The fluctuations correlate directly to the execution of new customer contracts and to invoicing and collections from customers in the normal course of business. (2) Fluctuation is primarily due to the timing of payments on our contracts measured using the cost-to-cost method of revenue recognition. (3) Included in other current assets and other noncurrent assets on the Consolidated Balance Sheets. During the year ended October 31, 2020, we capitalized $16.4 million of new costs and amortized $13.0 million of previously capitalized costs. There was no impairment loss recorded on the costs capitalized. (in millions) Year Ended Contract liabilities (1) Balance at beginning of year $ 38.0 Additional contract liabilities 315.5 Recognition of deferred revenue (317.1) Balance at end of year $ 36.4

Leases

Leases	12 Months Ended
	Oct. 31, 2020
Leases [Abstract]
Leases	LEASES The components of lease assets and liabilities and their classification on our Consolidated Balance Sheets as of October 31, 2020 were as follows: Balance at (in millions) Classification October 31, 2020 Lease assets Operating leases Right-of-use assets $ 143.1 Finance leases Property, plant and equipment, net (1) 6.1 Total lease assets $ 149.2 Lease liabilities Current liabilities Operating leases Current portion of lease liabilities $ 35.0 Finance leases Other accrued liabilities 2.3 Noncurrent liabilities Operating leases Long-term lease liabilities 131.4 Finance leases Other noncurrent liabilities 2.8 Total lease liabilities $ 171.4 (1) Finance lease assets are recorded net of accumulated amortization of $13.6 million as of October 31, 2020. Total lease costs for the year ended October 31, 2020 were $100.4 million, including operating leases of $96.4 million and finance leases of $4.0 million. The components of lease costs and classification within the Consolidated Statements of Comprehensive (Loss) Income were as follows: (in millions) Year Ended Operating lease costs: Operating expenses (1)(2) $ 67.9 Selling, general and administrative expenses (3) 28.5 Finance lease costs: Operating expenses (4) 3.5 Interest expense (5) 0.5 Total lease costs $ 100.4 (1) Related to certain parking arrangements. (2) Includes short-term lease costs and variable lease costs. (3) Includes short-term lease costs. (4) Represents amortization of leased assets. (5) Interest on lease liabilities. The following table presents information on short-term and variable lease costs: (in millions) Year Ended Short-term lease costs $ 47.0 Variable lease costs 3.5 Total short-term and variable lease costs $ 50.5 Sublease income generated during the year ended October 31, 2020 was immaterial. We continue to monitor the impact of the Pandemic on our subleases; however, we do not expect a significant impact. The amounts of future undiscounted cash flows related to the lease payments over the lease terms and the reconciliation to the present value of the lease liabilities as recorded on our Consolidated Balance Sheets as of October 31, 2020 are as follows: (in millions) Operating Finance Total Fiscal 2021 $ 41.3 $ 3.3 $ 44.6 Fiscal 2022 34.3 1.7 36.0 Fiscal 2023 29.2 0.9 30.1 Fiscal 2024 24.1 — 24.1 Fiscal 2025 18.2 — 18.2 Thereafter 43.3 — 43.3 Total lease payments 190.4 5.9 196.3 Less: imputed interest 24.0 0.8 24.9 Present value of lease liabilities $ 166.4 $ 5.1 $ 171.4 Future sublease rental income was excluded for the periods shown above as the amounts are immaterial. We have entered into operating lease arrangements as of October 31, 2020 that are effective for future periods. The total amount of ROU assets and lease liabilities related to these arrangements is immaterial. The following table includes the weighted-average remaining lease terms, in years, and the weighted-average discount rate used to calculate the present value of operating lease liabilities: As of October 31, 2020 Weighted-average remaining lease term (years) Operating leases 6.1 Finance leases 2.0 Weighted-average discount rate Operating leases 4.14 % Finance leases 4.55 % The following table includes supplemental cash and non-cash information related to operating leases: (in millions) Year Ended Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 44.8 Operating cash flows from finance leases 0.5 Financing cash flows from finance leases 3.4 Lease assets obtained in exchange for new operating lease liabilities (1) 15.7 (1) Excludes the amount initially capitalized in conjunction with the adoption of Topic 842. The amounts of minimum future commitments under non-cancelable operating and capital leases as of October 31, 2019, in accordance with Topic 840 were as follows: (in millions) Operating and Other (1) Capital Total Fiscal 2020 $ 42.8 $ 3.1 $ 45.9 Fiscal 2021 35.5 2.5 38.0 Fiscal 2022 30.3 1.3 31.6 Fiscal 2023 25.6 0.6 26.2 Fiscal 2024 20.5 — 20.5 Thereafter 51.8 — 51.8 Total (2) $ 206.5 $ 7.5 $ 214.0 (1) Includes total estimated sublease rental income of $15.8 million.
Leases	LEASES The components of lease assets and liabilities and their classification on our Consolidated Balance Sheets as of October 31, 2020 were as follows: Balance at (in millions) Classification October 31, 2020 Lease assets Operating leases Right-of-use assets $ 143.1 Finance leases Property, plant and equipment, net (1) 6.1 Total lease assets $ 149.2 Lease liabilities Current liabilities Operating leases Current portion of lease liabilities $ 35.0 Finance leases Other accrued liabilities 2.3 Noncurrent liabilities Operating leases Long-term lease liabilities 131.4 Finance leases Other noncurrent liabilities 2.8 Total lease liabilities $ 171.4 (1) Finance lease assets are recorded net of accumulated amortization of $13.6 million as of October 31, 2020. Total lease costs for the year ended October 31, 2020 were $100.4 million, including operating leases of $96.4 million and finance leases of $4.0 million. The components of lease costs and classification within the Consolidated Statements of Comprehensive (Loss) Income were as follows: (in millions) Year Ended Operating lease costs: Operating expenses (1)(2) $ 67.9 Selling, general and administrative expenses (3) 28.5 Finance lease costs: Operating expenses (4) 3.5 Interest expense (5) 0.5 Total lease costs $ 100.4 (1) Related to certain parking arrangements. (2) Includes short-term lease costs and variable lease costs. (3) Includes short-term lease costs. (4) Represents amortization of leased assets. (5) Interest on lease liabilities. The following table presents information on short-term and variable lease costs: (in millions) Year Ended Short-term lease costs $ 47.0 Variable lease costs 3.5 Total short-term and variable lease costs $ 50.5 Sublease income generated during the year ended October 31, 2020 was immaterial. We continue to monitor the impact of the Pandemic on our subleases; however, we do not expect a significant impact. The amounts of future undiscounted cash flows related to the lease payments over the lease terms and the reconciliation to the present value of the lease liabilities as recorded on our Consolidated Balance Sheets as of October 31, 2020 are as follows: (in millions) Operating Finance Total Fiscal 2021 $ 41.3 $ 3.3 $ 44.6 Fiscal 2022 34.3 1.7 36.0 Fiscal 2023 29.2 0.9 30.1 Fiscal 2024 24.1 — 24.1 Fiscal 2025 18.2 — 18.2 Thereafter 43.3 — 43.3 Total lease payments 190.4 5.9 196.3 Less: imputed interest 24.0 0.8 24.9 Present value of lease liabilities $ 166.4 $ 5.1 $ 171.4 Future sublease rental income was excluded for the periods shown above as the amounts are immaterial. We have entered into operating lease arrangements as of October 31, 2020 that are effective for future periods. The total amount of ROU assets and lease liabilities related to these arrangements is immaterial. The following table includes the weighted-average remaining lease terms, in years, and the weighted-average discount rate used to calculate the present value of operating lease liabilities: As of October 31, 2020 Weighted-average remaining lease term (years) Operating leases 6.1 Finance leases 2.0 Weighted-average discount rate Operating leases 4.14 % Finance leases 4.55 % The following table includes supplemental cash and non-cash information related to operating leases: (in millions) Year Ended Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 44.8 Operating cash flows from finance leases 0.5 Financing cash flows from finance leases 3.4 Lease assets obtained in exchange for new operating lease liabilities (1) 15.7 (1) Excludes the amount initially capitalized in conjunction with the adoption of Topic 842. The amounts of minimum future commitments under non-cancelable operating and capital leases as of October 31, 2019, in accordance with Topic 840 were as follows: (in millions) Operating and Other (1) Capital Total Fiscal 2020 $ 42.8 $ 3.1 $ 45.9 Fiscal 2021 35.5 2.5 38.0 Fiscal 2022 30.3 1.3 31.6 Fiscal 2023 25.6 0.6 26.2 Fiscal 2024 20.5 — 20.5 Thereafter 51.8 — 51.8 Total (2) $ 206.5 $ 7.5 $ 214.0 (1) Includes total estimated sublease rental income of $15.8 million.

Restructuring and Related Costs

Restructuring and Related Costs	12 Months Ended
	Oct. 31, 2020
Restructuring and Related Activities [Abstract]
Restructuring and Related Costs	RESTRUCTURING AND RELATED COSTS We may periodically engage in various restructuring activities intended to drive long-term profitable growth and increase operational efficiency, which can include streamlining and realigning our overall organizational structure and reallocating resources. These activities may result in restructuring costs related to employee severance, other project fees, external support fees, lease exit costs, and asset impairment charges. Recently, our significant restructuring activities have been primarily associated with integrating our acquisition of GCA and implementing our 2020 Vision initiative, as described below. GCA Restructuring and Other Initiatives Following the acquisition of GCA, during the first quarter of 2018 we initiated a restructuring program to achieve cost synergies and subsequently incurred expenses primarily related to employee severance, the migration and upgrade of several key technology platforms, and the consolidation of certain real estate leases. Additionally, during 2019 we reorganized our former Healthcare business and incurred immaterial severance expense. In early 2020 we continued our technology-based modernization efforts, including standardizing our financial systems. However, due to the Pandemic, the majority of these projects have been temporarily suspended since the second quarter of 2020. 2020 Vision Restructuring During the fourth quarter of 2015, we initiated a restructuring plan as part of a comprehensive strategy intended to have a positive transformative effect on ABM. These actions were substantially completed by the end of fiscal 2019 at a cumulative cost of $66.5 million. Rollforward of Restructuring and Related Liabilities (in millions) External Support Fees Employee Severance Other Project Fees Lease Exit Costs Asset Impairment Total Balance, October 31, 2017 $ 2.5 $ 2.7 $ 0.4 $ 2.8 $ — $ 8.4 Costs recognized (1) 4.0 11.0 8.2 2.0 0.6 25.7 Payments (6.5) (9.9) (6.7) (1.5) — (24.7) Non-cash items — — — (0.2) (0.6) (0.7) Balance, October 31, 2018 $ — $ 3.8 $ 1.8 $ 3.1 $ — $ 8.6 Costs recognized (1) 1.5 4.6 4.5 0.7 — 11.2 Payments (1.0) (5.3) (5.6) (1.1) — (12.9) Balance, October 31, 2019 $ 0.5 $ 3.0 $ 0.7 $ 2.7 $ — $ 7.0 Costs recognized (1) 1.4 0.3 3.2 2.7 — 7.6 Payments (1.9) (2.0) (3.7) (0.2) — (7.9) Non-cash items — — (0.2) (5.3) — (5.4) Balance, October 31, 2020 $ — $ 1.3 $ — $ — $ — $ 1.3 (1) We include these costs within corporate expenses. Cumulative Restructuring and Related Charges (in millions) External Support Fees Employee Severance Other Project Fees Lease Exit Costs Asset Impairment Total GCA and Other $ 4.9 $ 18.3 $ 15.5 $ 3.4 $ — $ 42.2 2020 Vision 30.0 13.0 10.7 7.7 5.2 66.5 Total $ 34.9 $ 31.3 $ 26.2 $ 11.1 $ 5.2 $ 108.7

Net Income Per Common Share

Net Income Per Common Share	12 Months Ended
	Oct. 31, 2020
Earnings Per Share [Abstract]
Net Income Per Common Share	NET INCOME PER COMMON SHARE Basic and Diluted Net Income Per Common Share Calculations Years Ended October 31, (in millions, except per share amounts) 2020 2019 2018 Income from continuing operations $ 0.2 $ 127.5 $ 95.9 Income (loss) from discontinued operations, net of taxes 0.1 (0.1) 1.8 Net income $ 0.3 $ 127.4 $ 97.8 Weighted-average common and common equivalent 66.9 66.6 66.1 Effect of dilutive securities RSUs 0.1 0.2 0.1 Stock options 0.1 0.1 0.1 Performance shares 0.1 0.1 — Weighted-average common and common equivalent 67.3 66.9 66.4 Net income per common share — Basic Income from continuing operations $ 0.00 $ 1.92 $ 1.45 Income from discontinued operations — — 0.03 Net income $ 0.00 $ 1.91 $ 1.48 Net income per common share — Diluted Income from continuing operations $ 0.00 $ 1.91 $ 1.45 Income from discontinued operations — — 0.03 Net income $ 0.00 $ 1.90 $ 1.47 Anti-Dilutive Outstanding Stock Awards Issued Under Share-Based Compensation Plans Years Ended October 31, (in millions) 2020 2019 2018 Anti-dilutive 0.4 0.3 0.4

Fair Value of Financial Instrum

Fair Value of Financial Instruments	12 Months Ended
	Oct. 31, 2020
Fair Value Disclosures [Abstract]
Fair Value of Financial Instruments	FAIR VALUE OF FINANCIAL INSTRUMENTS Fair Value Hierarchy of Our Financial Instruments Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis As of October 31, (in millions) Fair Value Hierarchy 2020 2019 Cash and cash equivalents (1) 1 $ 394.2 $ 58.5 Insurance deposits (2) 1 0.7 0.8 Assets held in funded deferred compensation plan (3) 1 2.6 2.5 Credit facility (4) 2 725.3 808.4 Interest rate swap liabilities (5) 2 15.5 14.6 Investments in auction rate securities (6) 3 — 5.0 (1) Cash and cash equivalents are stated at nominal value, which equals fair value. (2) Represents restricted deposits that are used to collateralize our insurance obligations and are stated at nominal value, which equals fair value. These insurance deposits are included in “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. See Note 10, “Insurance,” for further information. (3) Represents investments held in a Rabbi trust associated with one of our deferred compensation plans, which we include in “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. The fair value of the assets held in the funded deferred compensation plan is based on quoted market prices. See Note 12, “Employee Benefit Plans,” for further information. (4) Represents gross outstanding borrowings under our syndicated line of credit and term loan. Due to variable interest rates, the carrying value of outstanding borrowings under our line of credit and term loan approximates the fair value. See Note 11, “Credit Facility,” for further information. (5) Represents interest rate swap derivatives designated as cash flow hedges. The fair values of the interest rate swaps are estimated based on the present value of the difference between expected cash flows calculated at the contracted interest rates and the expected cash flows at current market interest rates using observable benchmarks for the London Interbank Offered Rate (“LIBOR”) forward rates at the end of the period. At October 31, 2020 and 2019, our interest rate swaps are included in “Other noncurrent liabilities” on the accompanying Consolidated Balance Sheets. See Note 11, “Credit Facility,” for further information. (6) The fair value of investments in auction rate securities is based on discounted cash flow valuation models, primarily utilizing unobservable inputs, including assumptions about the underlying collateral, credit risks associated with the issuer, credit enhancements associated with financial insurance guarantees, and the possibility of the security being refinanced by the issuer or having a successful auction. At October 31, 2019, we held an investment in one auction rate security that had an original principal amount, amortized cost, and fair value of $5.0 million that was included in “Other investments” on the accompanying Consolidated Balance Sheets. During the first quarter of 2020, this auction rate security was called by the issuer, and we received proceeds for the fair value of this debt instrument of $5.0 million. There were no unrealized gains or losses on this auction rate security included in AOCL. At October 31, 2020, we had no investments in auction rate securities. During 2020 and 2019, we had no transfers of assets or liabilities between any of the above hierarchy levels. Non-Financial Assets Measured at Fair Value on a Non-Recurring Basis In addition to assets and liabilities that are measured at fair value on a recurring basis, we are also required to measure certain items at fair value on a non-recurring basis. These assets can include: goodwill; intangible assets; property, plant and equipment; lease-related ROU assets; and long-lived assets that have been reduced to fair value when they are held for sale. If certain triggering events occur, or if an annual impairment test is required, we would evaluate these non-financial assets for impairment. If an impairment were to occur, the asset would be recorded at the estimated fair value, using primarily unobservable Level 3 inputs.

Property, Plant and Equipment

Property, Plant and Equipment	12 Months Ended
	Oct. 31, 2020
Property, Plant and Equipment [Abstract]
Property, Plant and Equipment	PROPERTY, PLANT AND EQUIPMENT Property, Plant and Equipment As of October 31, (in millions) 2020 2019 Machinery and other equipment $ 137.0 $ 118.8 Computer equipment and software 101.2 91.7 Transportation equipment 57.7 57.4 Leasehold improvements 57.1 59.5 Furniture and fixtures 13.7 13.1 Buildings 7.6 8.2 Land 0.7 1.0 375.0 349.8 Less: Accumulated depreciation (1) 241.3 199.5 Total $ 133.7 $ 150.3 (1) For 2020, 2019, and 2018, depreciation expense was $48.0 million, $48.9 million, and $46.5 million, respectively. Finance Leases Included in Property, Plant and Equipment As of October 31, (in millions) 2020 2019 Transportation equipment $ 19.4 $ 20.0 Furniture and fixtures 0.2 0.2 Machinery and other equipment — 0.3 Computer equipment and software — 0.1 19.7 20.6 Less: Accumulated depreciation 13.6 10.7 Total $ 6.1 $ 9.9

Goodwill and Other Intangible A

Goodwill and Other Intangible Assets	12 Months Ended
	Oct. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Other Intangible Assets	GOODWILL AND OTHER INTANGIBLE ASSETS During the second quarter of 2020, given the general deterioration in economic and market conditions arising from the Pandemic, we identified a triggering event which resulted in impairment of goodwill and intangible assets. Goodwill (in millions) Business & Industry Technology & Manufacturing Education Aviation Technical Solutions Healthcare Total Balance at October 31, 2018 $ 527.9 $ 407.2 $ 557.4 $ 124.9 $ 158.7 $ 58.7 $ 1,834.8 Reallocation (1) 45.7 — 1.2 — 11.8 (58.7) — Foreign currency translation 0.3 — — 0.1 0.3 — 0.6 Balance at October 31, 2019 $ 573.9 $ 407.2 $ 558.6 $ 125.0 $ 170.7 $ — $ 1,835.4 Foreign currency translation 0.1 — — — (0.3) — (0.2) Impairment loss (2) — — (99.3) (55.5) (9.0) (163.8) Balance at October 31, 2020 $ 574.0 $ 407.2 $ 459.3 $ 69.5 $ 161.5 $ — $ 1,671.4 (1) Goodwill associated with our Healthcare business was reallocated in connection with the reorganization of this business during the third quarter of 2019. (2) The impairment charge is included in “Impairment loss” on our Consolidated Statements of Comprehensive (Loss) Income for the year ended October 31, 2020, and is not tax deductible. Due to the triggering event identified above arising from the impact of the Pandemic, we first performed a qualitative assessment of goodwill to determine whether it was more likely than not that impairment occurred within our goodwill reporting units in the second quarter of 2020. Based on this qualitative assessment, we determined that goodwill impairment was not more likely than not in our goodwill reporting units, except in Education, Aviation, and our U.K. Technical Solutions business. As a result, we performed an interim quantitative impairment test as of March 31, 2020, on these three goodwill reporting units. For the three goodwill reporting units tested quantitatively, we estimated the fair value using a weighting of fair values derived from an income approach and a market approach. The income approach incorporates the use of a discounted cash flow method in which the estimated future cash flows and terminal value are calculated for each reporting unit and then discounted to present value using an appropriate discount rate. The discount rates utilized in the income approach valuation method are summarized in the table below. Discount Education 10.0% Aviation 10.5% Technical Solutions 11.0% The market approach estimates the fair value of a reporting unit by using market comparables for reasonably similar public companies and a control premium of 15.0%. The valuation of our reporting units requires significant judgment in evaluating recent indicators of market activity and estimated future cash flows, discount rates, and other factors. Our impairment analyses contain inherent uncertainties due to uncontrollable events that could positively or negatively impact anticipated future economic and operating conditions. In making these estimates, the weighted-average cost of capital is utilized to calculate the present value of future cash flows and terminal value. Many variables go into estimating future cash flows, including estimates of our future revenue growth and operating results. When estimating our projected revenue growth and future operating results, we consider industry trends, economic data, and our competitive advantage. If future cash flows or future growth rates vary from what is expected, including those assumptions relating to the duration and severity of the Pandemic, this may reduce the underlying cash flows used to estimate fair values and result in a further decline in fair value, which may trigger future impairment charges. Other Intangible Assets October 31, 2020 October 31, 2019 (in millions) Gross Carrying Amount Accumulated Amortization Total Gross Carrying Amount Accumulated Amortization Total Customer contracts and relationships (1) $ 573.1 $ (333.6) $ 239.6 $ 595.9 $ (298.9) $ 297.0 Trademarks and trade names 9.8 (9.8) — 9.8 (9.8) 0.1 Contract rights and other 0.5 (0.4) 0.1 0.5 (0.4) 0.1 Total (2) $ 583.5 $ (343.8) $ 239.7 $ 606.2 $ (309.0) $ 297.2 (1) Reflects a net impairment charge of $9.0 million recorded in 2020 as a result of the triggering event described above. We recognized net impairment charges of $5.6 million related to Aviation (consisting of a $13.8 million reduction in the gross carrying amount of the underlying customer relationships less $8.2 million of accumulated amortization) and $3.4 million related to our U.K. Technical Solutions business (consisting of an $8.7 million reduction in the gross carrying amount of the underlying customer relationships less $5.3 million of accumulated amortization). These impairment charges are included in “Impairment loss” on our Consolidated Statements of Comprehensive (Loss) Income for the year ended October 31, 2020. We did not record impairment charges on other intangible assets during 2019. (2) These intangible assets are being amortized over the expected period of benefit, with a weighted average life of approximately 11 years. Estimated Annual Amortization Expense For Each of the Next Five Years (in millions) 2021 2022 2023 2024 2025 Estimated amortization expense (1) $ 42.1 $ 36.8 $ 32.2 $ 28.0 $ 23.9 (1) These amounts could vary as acquisitions of additional intangible assets occur in the future. The estimates of future cash flows used in determining the fair value of goodwill and other intangible assets involve significant management judgment and are based upon assumptions about expected future operating performance, economic conditions, market conditions, and cost of capital. Inherent in estimating the future cash flows are uncertainties beyond our control, such as changes in capital markets. The actual cash flows could differ materially from management’s estimates due to changes in business conditions, operating performance, and economic conditions.

Insurance

Insurance	12 Months Ended
	Oct. 31, 2020
Insurance [Abstract]
Insurance	INSURANCE We use a combination of insured and self-insurance programs to cover workers’ compensation, general liability, automobile liability, property damage, and other insurable risks. For the majority of these insurance programs, we retain the initial $1.0 million to $1.5 million of exposure on a per-occurrence basis, either through deductibles or self-insured retentions. Beyond the retained exposures, we have varying primary policy limits ranging between $1.0 million and $5.0 million per occurrence. To cover general liability and automobile liability losses above these primary limits, we maintain commercial umbrella insurance policies that provide aggregate limits of $200.0 million. Our insurance policies generally cover workers’ compensation losses to the full extent of statutory requirements. Additionally, to cover property damage risks above our retained limits, we maintain policies that provide per occurrence limits of $75.0 million. We are also self-insured for certain employee medical and dental plans. We maintain stop-loss insurance for our self-insured medical plan under which we retain up to $0.5 million of exposure on a per-participant, per-year basis with respect to claims. We maintain our reserves for workers’ compensation, general liability, automobile liability, and property damage insurance claims based upon known trends and events and the actuarial estimates of required reserves considering the most recently completed actuarial reports. We use all available information to develop our best estimate of insurance claims reserves as information is obtained. The results of actuarial reviews are used to estimate our insurance rates and insurance reserves for future periods and to adjust reserves, if appropriate, for prior years. Insurance Reserve Adjustments Actuarial Reviews and Updates Performed During 2020 We review our self-insurance liabilities on a regular basis and adjust our accruals accordingly. Actual claims activity or development may vary from our assumptions and estimates, which may result in material losses or gains. As we obtain additional information that affects the assumptions and estimates used in our reserve liability calculations, we adjust our self-insurance rates and reserves for future periods and, if appropriate, adjust our reserves for claims incurred in prior accounting periods. During the first and third quarters of 2020, we performed comprehensive actuarial reviews of the majority of our casualty insurance programs to evaluate changes made to claims reserves and claims payment activity for the periods of May 1, 2019, through October 31, 2019, and November 1, 2019, through April 30, 2020, respectively (the “Actuarial Reviews”). The Actuarial Reviews were comprehensive in nature and were based on loss development patterns, trend assumptions, and underlying expected loss costs during the periods analyzed. During the second and fourth quarters of 2020, we performed interim actuarial updates of the majority of our casualty insurance programs that considered changes in claims development and claims payment activity for the respective periods analyzed (the “Interim Updates”). These Interim Updates were abbreviated in nature based on actual versus expected development during the periods analyzed and relied on the key assumptions in the Actuarial Reviews (most notably loss development patterns, trend assumptions, and underlying expected loss costs). Based on the results of the Actuarial Reviews and Interim Updates, we decreased our total reserves for known claims as well as our estimate of the loss amounts associated with IBNR Claims by $36.6 million, $30.2 million of which relates to prior years, during 2020 . In 2019, we decreased our total reserves related to prior year claims by $3.4 million. Insurance Related Balances and Activity (in millions) October 31, 2020 October 31, 2019 Insurance claim reserves, excluding medical and dental $ 504.9 $ 507.8 Medical and dental claim reserves 16.6 7.2 Insurance recoverables 70.1 64.5 At October 31, 2020 and 2019, insurance recoverables are included in both “Other current assets” and “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. Casualty Program Insurance Reserves Rollforward Years Ended October 31, (in millions) 2020 2019 2018 Net balance at beginning of year $ 443.3 $ 427.7 $ 412.5 Change in case reserves plus IBNR Claims — current year 128.5 137.9 131.4 Change in case reserves plus IBNR Claims — prior years (30.2) (3.4) 10.2 Claims paid (106.8) (119.1) (126.5) GCA acquisition 0.2 — 0.1 Net balance, October 31 (1) 434.8 443.3 427.7 Recoverables 70.1 64.5 73.7 Gross balance, October 31 $ 504.9 $ 507.8 $ 501.4 (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. Instruments Used to Collateralize Our Insurance Obligations As of October 31, (in millions) 2020 2019 Standby letters of credit $ 143.6 $ 141.0 Surety bonds 82.6 90.8 Restricted insurance deposits 0.7 0.8 Total $ 226.9 $ 232.6

Credit Facility

Credit Facility	12 Months Ended
	Oct. 31, 2020
Debt Disclosure [Abstract]
Credit Facility	CREDIT FACILITY On September 1, 2017, we refinanced and replaced our then-existing $800.0 million credit facility with a new senior, secured five-year syndicated credit facility, consisting of a $900.0 million revolving line of credit and an $800.0 million amortizing term loan, both of which are scheduled to mature on September 1, 2022. In accordance with the terms of the Credit Facility, the revolving line of credit was reduced to $800.0 million on September 1, 2018. In late March 2020, we borrowed approximately $300 million as a precautionary measure to provide increased liquidity and preserve financial flexibility in response to uncertainty resulting from the Pandemic. This represented all remaining amounts then available under the revolving line of credit. During the quarter ended July 31, 2020, the Company repaid substantially all of these amounts borrowed under the revolving line of credit without penalty. The Credit Facility also provides for the issuance of up to $300.0 million for standby letters of credit and the issuance of up to $75.0 million in swingline advances. The obligations under the Credit Facility are secured on a first-priority basis by a lien on substantially all of our assets and properties, subject to certain exceptions. To further enhance our financial flexibility as a precautionary measure in response to uncertainty arising from the Pandemic, we amended our Credit Facility on May 28, 2020, as further described below. The Amendment modified the financial covenants under the Credit Facility, including: (i) replacing a maximum total leverage ratio with a maximum total net leverage ratio that varies on a quarterly basis and adjusted to 6.50 to 1.00 by the quarter ending October 31, 2020, and back to 4.00 to 1.00 by the quarter ending October 31, 2022; (ii) modifying the minimum fixed charge coverage ratio on a quarterly basis, which adjusts to 1.25 to 1.00 as of the quarter ending April 30, 2022; and (iii) adding a minimum liquidity (defined in the Amendment as domestic cash plus available revolving loans) of $250.0 million. These financial covenants were effective with the quarter ended April 30, 2020. Our borrowing capacity is subject to, and limited by, compliance with these covenants. The Amendment changed the interest rate, interest margins, and commitment fees applicable to loans and commitments under the Credit Facility. It also added a new anti-cash hoarding mandatory prepayment that requires us to repay outstanding revolving loans or swingline loans if at any time we have in excess of $250 million of cash and cash equivalents on our balance sheet. The Amendment made certain additional changes to the negative covenants restrictions under the Credit Facility, including, subject to certain exceptions, restrictions on our ability to make acquisitions, share repurchases, and other defined restricted payments, depending on our total net leverage ratio. The anti-cash hoarding provision and certain of these restrictions were terminated from the Credit Facility in the fourth quarter of 2020 due to our favorable cash flow position and leverage ratios. At October 31, 2020, we were in compliance with these covenants. Prior to the Amendment, borrowings under the Credit Facility bore interest at a rate equal to 1-month LIBOR plus a spread that was based upon our leverage ratio. The spread ranged from 1.00% to 2.25% for Eurocurrency loans and 0.00% to 1.25% for base rate loans. We were also charged a commitment fee, which was paid quarterly in arrears and was based on our leverage ratio, that ranged from 0.200% to 0.350% on the average daily unused portion of the revolving line of credit. For purposes of this calculation, irrevocable standby letters of credit, which are issued primarily in conjunction with our insurance programs, and cash borrowings were included as outstanding under the line of credit. Subsequent to the Amendment, borrowings under the Credit Facility bear interest at a rate equal to 1-month LIBOR plus a spread that is based upon our total leverage ratio. The spread ranges from 1.00% to 2.75% for revolving Eurocurrency loans and 0.00% to 1.75% for revolving base rate loans. At October 31, 2020, the weighted average interest rate on our outstanding borrowings was 2.45%. We are also charged a commitment fee, which is paid quarterly in arrears and is based on our total leverage ratio, that ranges from 0.200% to 0.450% on the average daily unused portion of the revolving line of credit. For purposes of this calculation, irrevocable standby letters of credit, which are issued primarily in conjunction with our insurance programs, and cash borrowings are included as outstanding under the revolving line of credit. The Credit Facility also includes customary events of default, such as: failure to pay principal, interest, or fees when due; failure to comply with covenants; the occurrence of certain material judgments and a change in control of the Company. If certain events of default occur, including certain cross-defaults, insolvency, change in control, or violation of specific covenants, the lenders can terminate or suspend our access to the Credit Facility, declare all amounts outstanding (including all accrued interest and unpaid fees) to be immediately due and payable, and require that we cash collateralize the outstanding standby letters of credit. Total deferred financing costs related to the Credit Facility of $18.7 million, consisting of $13.4 million related to the term loan and $5.2 million related to the line of credit, are being amortized to interest expense over the term of the Credit Facility. We incurred total fees of $4.6 million in conjunction with the Amendment, the majority of which we capitalized in the quarter ended July 31, 2020, and are amortizing over the remaining term of the Credit Facility. Credit Facility Information (in millions) October 31, 2020 October 31, 2019 Current portion of long-term debt Gross term loan $ 120.0 $ 60.0 Unamortized deferred financing costs (3.3) (2.8) Current portion of term loan $ 116.7 $ 57.2 Long-term debt Gross term loan $ 560.0 $ 680.0 Unamortized deferred financing costs (2.3) (4.1) Total noncurrent portion of term loan 557.7 675.9 Revolving line of credit (1)(2) 45.3 68.4 Long-term debt $ 603.0 $ 744.2 (1) Standby letters of credit amounted to $153.1 million at October 31, 2020. (2) At October 31, 2020, we had borrowing capacity of $596.6 million, reflecting covenant restrictions. Term Loan Maturities During 2020, we made principal payments under the term loan of $60.0 million. As of October 31, 2020, the following principal payments are required under the term loan. (in millions) 2021 2022 Debt maturities $ 120.0 $ 560.0 Interest Rate Swaps We enter into interest rate swaps to manage the interest rate risk associated with our floating-rate, LIBOR-based borrowings. Under these arrangements, we typically pay a fixed interest rate in exchange for LIBOR-based variable interest throughout the life of the agreement. We initially report the mark-to-market gain or loss on a derivative as a component of AOCL and subsequently reclassify the gain or loss into earnings when the hedged transactions occur and affect earnings. Interest payables and receivables under the swap agreements are accrued and recorded as adjustments to interest expense. All of our interest rate swaps have been designated and accounted for as cash flow hedges from inception. See Note 7, “Fair Value of Financial Instruments,” regarding the valuation of our interest rate swaps. Notional Amount Fixed Interest Rate Effective Date Maturity Date $ 90.0 million 2.83% November 1, 2018 April 30, 2021 $ 90.0 million 2.84% November 1, 2018 October 31, 2021 $ 130.0 million 2.86% November 1, 2018 April 30, 2022 $ 130.0 million 2.84% November 1, 2018 September 1, 2022 At October 31, 2020 and 2019, amounts recorded in AOCL for interest rate swaps were a loss of $3.3 million, net of taxes of $0.9 million, and a gain of $2.2 million, net of taxes of $1.2 million, respectively. These amounts included the gain associated with the interest rate swaps we terminated in 2018, which is being amortized to interest expense as interest payments are made over the term of our Credit Facility. During 2020, we amortized $4.9 million, net of taxes of $1.8 million, of that gain and we amortized $4.1 million, net of taxes of $1.5 million, during 2019. At October 31, 2020, the total amount expected to be reclassified from AOCL to earnings during the next twelve months was $4.0 million, net of a tax benefit of $1.4 million.

Employee Benefit Plans

Employee Benefit Plans	12 Months Ended
	Oct. 31, 2020
Retirement Benefits [Abstract]
Employee Benefit Plans	EMPLOYEE BENEFIT PLANS Defined Benefit Plans We provide benefits to certain employees under various defined benefit and postretirement benefit plans (collectively, the “Plans”). The Plans were previously amended to preclude new participants. All but one of the Plans are unfunded. Information for the Plans As of October 31, (in millions) 2020 2019 Net obligations $ 9.6 $ 8.4 Projected benefit obligations 17.0 16.1 Fair value of assets 7.4 7.8 At October 31, 2020, assets of the Plans were investe d 48% in equities, 51% in fixed income, and 1% in cash. The expected return on assets was $0.4 million during each of 2020, 2019, and 2018 . The aggregate net periodic benefit cost for all Plans was $0.2 million, $0.6 million, and $0.2 million for 2020, 2019, and 2018, respectively. Future benefit payments in the aggregate are expected to be $14.4 million . Deferred Compensation Plans We maintain deferred compensation plans that permit eligible employees and directors to defer a portion of their compensation. At October 31, 2020 and 2019, the total liability of all deferred compensation was $13.6 million and $13.2 million, respectively, and these amounts are included in “Other accrued liabilities” and “Other noncurrent liabilities” on the accompanying Consolidated Balance Sheets. Under one of our deferred compensation plans, a Rabbi trust was created to fund the obligations, and we are required to contribute a portion of the deferred compensation contributions for eligible participants. The assets held in the Rabbi trust are not available for general corporate purposes. At October 31, 2020 and 2019, the fair value of these assets was $2.6 million and $2.5 million, respectively, and these amounts are included in “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. Aggregate expense recognized under these deferred compensation plans wa s $0.2 million, $0.3 million, and $0.4 million for 2020, 2019, and 2018, respectively. Defined Contribution Plans We sponsor four defined contribution plans covering certain employees that are subject to the applicable provisions of the Employee Retirement Income Security Act of 1974 and the Internal Revenue Code (“IRC”). Certain plans permit a company match of a portion of the participant’s contributions or a discretionary contribution after the participant has met the eligibility requirements set forth in the plan. During 2020, 2019, and 2018, we made matching contributions required by the plans of $18.2 million, $24.3 million, and $21.6 million, respectively. Multiemployer Pension and Postretirement Plans We participate in various multiemployer pension plans under union and industry-wide agreements that provide defined pension benefits to employees covered by collective bargaining agreements. Because of the nature of multiemployer plans, there are risks associated with participation in these plans that differ from single-employer plans. Assets contributed by an employer to a multiemployer plan are not segregated into a separate account and are not restricted to provide benefits only to employees of that contributing employer. In the event another participating employer in a multiemployer plan no longer contributes to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers, including us. In the event of the termination of a multiemployer pension plan or a withdrawal from a multiemployer pension plan, we could incur material liabilities under applicable law. Key Information for Individually Significant Multiemployer Defined Benefit Pension Plans (1) ($ in millions) Pension Protection Act Zone Status (3) FIP/RP Status (4) Contributions by ABM Surcharge Imposed (5) Expiration Dates of Collective Bargaining Agreements Pension Fund EIN/PN (2) 2020 2019 Pending/ 2020 2019 2018 Building Service 32BJ Pension Fund 13-1879376 / 001 Red 6/30/2019 Red Implemented $ 16.8 $ 19.3 $ 19.9 No 10/15/2023 – 12/31/2023 S.E.I.U. National Industry Pension Fund 52-6148540 / 001 Red 12/31/2019 Red Implemented 11.1 10.6 8.7 Yes 6/30/2021 – Central Pension Fund of the IUOE & Participating Employers 36-6052390 / 001 Green 1/31/2020 Green N/A* 7.1 11.7 11.0 N/A* 4/30/2021 – 12/31/2022 SEIU Local 1 & Participating Employers Pension Trust 36-6486542 / 001 Green 9/30/2019 Green N/A* 4.3 5.1 5.8 N/A* 4/4/2021 IUOE Stationary Engineers Local 39 Pension Plan 94-6118939 / 001 Green 12/31/2019 Green N/A* 4.3 4.6 5.2 N/A* 11/15/2020 – 10/31/2024 Western Conference of Teamsters Pension Plan 91-6145047 / 001 Green 12/31/2019 Green N/A* 2.5 3.1 3.1 N/A* 6/30/2021 – All Other Plans: 9.5 12.2 11.5 Total Contributions $ 55.5 $ 66.6 $ 65.3 *Not applicable (1) To determine individually significant plans, we evaluated several factors, including our total contributions to the plan, our significance to the plan in terms of participating employees and contributions, and the funded status of the plan. (2) The “EIN/PN” column provides the Employer Identification Number and the three-digit plan number assigned to the plan by the IRS. (3) The Pension Protection Act Zone Status columns provide the two most recently available Pension Protection Act zone statuses from each plan. The zone status is based on information provided to us and other participating employers and is certified by each plan’s actuary. Among other factors, plans in the red zone are generally less than 65% funded, plans in the yellow zone are less than 80% funded, and plans in the green zone are at least 80% funded. (4) Indicates whether a Financial Improvement Plan (“FIP”) for yellow zone plans or a Rehabilitation Plan (“RP”) for red zone plans is pending or implemented. (5) Indicates whether our contribution in 2020 included an amount as imposed by a plan in the red zone in addition to the contribution rate specified in the applicable collective bargaining agreement. Multiemployer Pension Plans for which ABM is a Significant Contributor Pension Fund Contributions to the plan exceeded more than 5% of total contributions per most currently available Forms 5500 Arizona Sheet Metal Pension Trust Fund* 6/30/2019 and 6/30/2018 Building Service 32BJ Pension Fund 6/30/2019, 6/30/2018, and 6/30/2017 Building Service Pension Plan* 4/30/2019, 4/30/2018, and 4/30/2017 Contract Cleaners Service Employees’ Pension Plan* 12/31/19, 12/31/2018, and 12/31/2017 Firemen & Oilers Pension Plan of SEIU Local 1* 7/31/2019, 7/31/2018, and 7/31/2017 Massachusetts Service Employees Pension Plan* 12/31/2019, 12/31/2018, and 12/31/2017 SEIU Local 1 & Participating Employers Pension Trust 9/30/2019, 9/30/2018, and 9/30/2017 S.E.I.U. National Industry Pension Fund 12/31/2019, 12/31/2018, and 12/31/2017 Service Employees International Union Local 1 Cleveland Pension Plan* 12/31/2019, 12/31/2018, and 12/31/2017 Service Employees International Union Local 32BJ, District 36 Building Operators Pension Trust Fund* 12/31/2019, 12/31/2018, and 12/31/2017 Teamsters Local 617 Pension Fund* 2/29/2020, 2/28/2019, and 2/28/2018 Teamsters Local Union No. 727 Pension Plan* 2/29/2020, 2/28/2019, and 2/28/2018 * These plans are not separately listed in our multiemployer table as they represent an insignificant portion of our total multiemployer pension plan contributions. There have been no significant changes that affect the comparability of total contributions for any of the periods presented. Multiemployer Defined Contribution Plans In addition to contributions noted above, we also make contributions to multiemployer defined contribution plans. During 2020, 2019, and 2018, our contributions to the defined contribution plans were $15.5 million, $9.0 million, and $10.6 million, respectively. Other Multiemployer Benefit Plans We also contribute to several multiemployer postretirement health and welfare plans based on obligations arising under collective bargaining agreements covering union-represented employees. These plans may provide medical, pharmacy, dental, vision, mental health, and other benefits to employees as determined by the trustees of each plan. The majority of our contributions benefit active employees and, as such, may not constitute contributions to a postretirement benefit plan. However, since we are unable to separate contribution amounts to postretirement benefit plans from contribution amounts paid to benefit active employees, we categorize all such amounts as contributions to postretirement benefit plans. During 2020, 2019, and 2018, our contributions to such plans wer e $264.8 million , $269.8 million, and $263.4 million, respectively. There have been no significant changes that affect the comparability of total contributions for any of the periods presented.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Oct. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	COMMITMENTS AND CONTINGENCIES Letters of Credit and Surety Bonds We use letters of credit and surety bonds to secure certain commitments related to insurance programs and for other purposes. As of October 31, 2020, these letters of credit and surety bonds totaled $153.1 million and $632.9 million, respectively. Guarantees In some instances, we offer clients guaranteed energy savings under certain energy savings contracts. At October 31, 2020 and 2019, total guarantees were $182.8 million and $174.8 million, respectively, and these guarantees extend through 2039 and 2038, respectively. We accrue for the estimated cost of guarantees when it is probable that a liability has been incurred and the amount can be reasonably estimated. Historically, we have not incurred any material losses in connection with these guarantees. In connection with an unconsolidated joint venture in which one of our subsidiaries has a 33% ownership interest, that subsidiary and the other joint venture partners have each jointly and severally guaranteed the obligations of the joint venture to perform under certain contracts extending through 2024. Annual revenues relating to the underlying contracts are approximately $30 million. Should the joint venture be unable to perform under these contracts, the joint venture partners would be jointly and severally liable for any losses incurred by the client due to the failure to perform. Indemnifications We are party to a variety of agreements under which we may be obligated to indemnify the other party for certain matters. These agreements are primarily standard indemnification arrangements entered into in our ordinary course of business. Pursuant to these arrangements, we may agree to indemnify, hold harmless, and reimburse the indemnified parties for losses suffered or incurred by the indemnified party, generally our clients, in connection with any claims arising out of the services that we provide. We also incur costs to defend lawsuits or settle claims related to these indemnification arrangements, and in most cases these costs are paid from our insurance program. Although we attempt to place limits on such indemnification arrangements related to the size of the contract, the maximum obligation may not be explicitly stated and, as a result, we are unable to determine the maximum potential amount of future payments we could be required to make under these arrangements. Our certificate of incorporation and bylaws may require us to indemnify our directors and officers for certain liabilities that were incurred as a result of their status or service to ABM as a director or officer. The amount of these obligations cannot be reasonably estimated. Unclaimed Property Audits We routinely remit escheat payments to states in compliance with applicable escheat laws, and we are subject to unclaimed property audits by states in the ordinary course of business. The property subject to review in the audit process may include unclaimed wages, vendor payments, or customer refunds. State escheat laws generally require entities to report and remit abandoned or unclaimed property to the state, and failure to do so can result in assessments that could include interest and penalties in addition to the payment of the escheat liability. Sales Tax Audits We collect sales tax from clients and remit those collections to the applicable states. When clients fail to pay their invoices, including the amount of any sales tax that we paid on their behalf, in some cases we are entitled to seek a refund of that amount of sales tax from the applicable state. Sales tax laws and regulations enacted by the various states are subject to interpretation, and our compliance with such laws is routinely subject to audit and review by such states. Audit risk is concentrated in several states that are conducting ongoing audits. The outcomes of ongoing and any future audits and changes in the states’ interpretation of the sales tax laws and regulations could materially adversely impact our results of operations. Legal Matters We are a party to a number of lawsuits, claims, and proceedings incident to the operation of our business, including those pertaining to labor and employment, contracts, personal injury, and other matters, some of which allege substantial monetary damages. Some of these actions may be brought as class actions on behalf of a class or purported class of employees. At October 31, 2020, the total amount accrued for probable litigation losses where a reasonable estimate of the loss could be made was $14.7 million. We do not accrue for contingent losses that, in our judgment, are considered to be reasonably possible but not probable. The estimation of reasonably possible losses also requires the analysis of multiple possible outcomes that often depend on judgments about potential actions by third parties. Our management currently estimates the range of loss for reasonably possible losses for which a reasonable estimate of the loss can be made is between zero and $4 million. Factors underlying this estimated range of loss may change from time to time, and actual results may vary significantly from this estimate. The amounts above do not include any accrual or loss estimates with respect to the Bucio case described below. Litigation outcomes are difficult to predict and the estimation of probable losses requires the analysis of multiple possible outcomes that often depend on judgments about potential actions by third parties. If one or more matters are resolved in a particular period in an amount in excess of, or in a manner different than, what we anticipated, this could have a material adverse effect on our financial position, results of operations, or cash flows. In some cases, although a loss is probable or reasonably possible, we cannot reasonably estimate the maximum potential losses for probable matters or the range of losses for reasonably possible matters. Therefore, our accrual for probable losses and our estimated range of loss for reasonably possible losses do not represent our maximum possible exposure. Certain Legal Proceedings In determining whether to include any particular lawsuit or other proceeding in our disclosure below, we consider both quantitative and qualitative factors. These factors include, but are not limited to: the amount of damages and the nature of any other relief sought in the proceeding; if such damages and other relief are specified, our view of the merits of the claims; whether the action is or purports to be a class action, and our view of the likelihood that a class will be certified by the court; the jurisdiction in which the proceeding is pending; and the potential impact of the proceeding on our reputation. The Consolidated Cases of Bucio and Martinez v. ABM Janitorial Services filed on April 7, 2006, pending in the Superior Court of California, County of San Francisco (the “Bucio case”) The Bucio case is a class action pending in San Francisco Superior Court that alleges we failed to provide legally required meal periods and make additional premium payments for such meal periods, pay split shift premiums when owed, and reimburse janitors for travel expenses. There is also a claim for penalties under the California Labor Code Private Attorneys General Act (“PAGA”). On April 19, 2011, the trial court held a hearing on plaintiffs’ motion to certify the class. At the conclusion of that hearing, the trial court denied plaintiffs’ motion to certify the class. On May 11, 2011, the plaintiffs filed a motion to reconsider, which was denied. The plaintiffs appealed the class certification issues. The trial court stayed the underlying lawsuit pending the decision in the appeal. The Court of Appeal of the State of California, First Appellate District (the “Court of Appeal”), heard oral arguments on November 7, 2017. On December 11, 2017, the Court of Appeal reversed the trial court’s order denying class certification and remanded the matter for certification of a meal period, travel expense reimbursement, and split shift class. The case was remitted to the trial court for further proceedings on class certification, discovery, dispositive motions, and trial. On September 20, 2018, the trial court entered an order defining four certified subclasses of janitors who were employed by the legacy ABM janitorial companies in California at any time between April 7, 2002, and April 30, 2013, on claims based on alleged previous automatic deduction practices for meal breaks, unpaid meal premiums, unpaid split shift premiums, and unreimbursed business expenses, such as mileage reimbursement for use of personal vehicles to travel between worksites. On February 1, 2019, the trial court held that the discovery related to PAGA claims allegedly arising after April 30, 2013, would be stayed until after the class and PAGA claims accruing prior to April 30, 2013, had been tried. The parties engaged in mediation in July 2019, which did not result in settlement of the case. On October 17, 2019, the plaintiffs filed a motion asking the trial court to certify additional classes based on an alleged failure to maintain time records, an alleged failure to provide accurate wage statements, and an alleged practice of combining meal and rest breaks. The trial court denied the plaintiffs’ motion to certify additional classes on December 26, 2019. The case was re-assigned to a new judge on January 6, 2020. ABM filed motions for summary adjudication as to certain of Plaintiffs’ class claims, and the trial court denied those motions in November 2020. Plaintiffs filed motions for summary adjudication and/or summary judgment on some claims in December 2020, and a hearing on these motions is currently set for February 24, 2021. The trial court has ordered that the parties complete another mediation by February 19, 2021. The parties are currently engaged in substantive briefing and will begin expert discovery. The class action claims accruing prior to April 30, 2013 are set for trial on July 12, 2021. Prior to trial, we will have the opportunity to, among other things, seek decertification of the classes, seek interlocutory appellate review, or engage in further mediation if we deem such actions appropriate. We may engage in one or more such activities before the trial.

Preferred and Common Stock

Preferred and Common Stock	12 Months Ended
	Oct. 31, 2020
Stockholders' Equity Note [Abstract]
Preferred and Common Stock	PREFERRED AND COMMON STOCK Preferred Stock We are authorized to issue 500,000 shares of preferred stock. None of these preferred shares are issued. Common Stock Effective December 18, 2019, our Board of Directors replaced our then-existing share repurchase program with a new share repurchase program under which we may repurchase up to $150.0 million of our common stock. These purchases may take place on the open market or otherwise, and all or part of the repurchases may be made pursuant to Rule 10b5-1 plans or in privately negotiated transactions. The timing of repurchases is at our discretion and will depend upon several factors, including market and business conditions, future cash flows, share price, share availability, and other factors at our discretion. Repurchased shares are retired and returned to an authorized but unissued status. The repurchase program may be suspended or discontinued at any time without prior notice. Repurchase Activity We repurchased shares under the 2019 Share Repurchase Program during the second quarter of 2020, as summarized below. However, due to the market and business conditions arising from the Pandemic, in March 2020 we suspended further repurchases of our common stock. At October 31, 2020, authorization for $144.9 million of repurchases remained under the 2019 Share Repurchase Program. There were no share repurchases during 2019 or 2018. Year Ended (in millions, except per share amounts) October 31, 2020 Total number of shares purchased 0.2 Average price paid per share $ 36.16 Total cash paid for share repurchases $ 5.1

Share-Based Compensation Plans

Share-Based Compensation Plans	12 Months Ended
	Oct. 31, 2020
Share-based Payment Arrangement [Abstract]
Share-Based Compensation Plans	SHARE-BASED COMPENSATION PLANS We use various share-based compensation plans to provide incentives for our key employees and directors. Currently, these incentives primarily consist of RSUs and performance shares. On May 2, 2006, our stockholders approved the 2006 Equity Incentive Plan (the “2006 Equity Plan”). The 2006 Equity Plan is an omnibus plan that provides for a variety of equity and equity-based award vehicles, including stock options, stock appreciation rights, RSUs, performance shares, and other share-based awards. Shares subject to awards that terminate without vesting or exercise are available for future awards under the 2006 Equity Plan. Certain of the awards under the 2006 Equity Plan may qualify as “performance-based” compensation under the IRC. As amended, there are 13,475,265 total shares of common stock authorized for issuance under the 2006 Equity Plan, and at October 31, 2020, there were 2,086,078 shares of common stock available for grant for future equity-based compensation awards. In addition, there are certain plans under which we can no longer issue awards, although awards outstanding under these plans may still vest and be exercised. We also maintain an employee stock purchase plan, which our stockholders approved on March 9, 2004 (the “2004 Employee Stock Purchase Plan”). As amended, there are 4,000,000 total shares of common stock authorized for issuance under the 2004 Employee Stock Purchase Plan. Effective May 1, 2006, the 2004 Employee Stock Purchase Plan is no longer considered compensatory and the values of the awards are no longer treated as share-based compensation expense. Additionally, as of that date, the purchase price became 95% of the fair value of our common stock price on the last trading day of the month. Employees may designate up to 10% of their compensation for the purchase of stock, subject to a $25,000 annual limit. Employees are required to hold their shares for a minimum of six months from the date of purchase. At October 31, 2020, there were 599,159 remaining unissued shares under the 2004 Employee Stock Purchase Plan. Compensation Expense by Type of Award and Related Income Tax Benefit Years Ended October 31, (in millions) 2020 2019 2018 RSUs $ 11.5 $ 9.5 $ 9.3 Performance shares 8.8 8.0 7.7 Share-based compensation expense before income taxes 20.3 17.5 17.0 Income tax benefit (5.7) (4.9) (5.1) Share-based compensation expense, net of taxes $ 14.6 $ 12.5 $ 11.8 RSUs and Dividend Equivalent Rights We award RSUs to eligible employees and our directors (each, a “Grantee”) that entitle the Grantee to receive shares of our common stock as the units vest. RSUs granted to eligible employees in 2020 generally vest ratably over three years. RSUs granted to eligible employees prior to 2020 generally vest with respect to 50% of the underlying award on the second and fourth anniversary of the award. RSUs granted to directors vest over three years. In general, the receipt of RSUs is subject to the Grantee’s continuing employment or service as a director. RSUs are credited with dividend equivalent rights that are converted to RSUs at the fair market value of our common stock on the dates the dividend payments are made and are subject to the same terms and conditions as the underlying award. RSU Activity Number of Weighted-Average Outstanding at October 31, 2019 0.7 $ 36.92 Granted 0.7 36.11 Vested (including 0.1 shares withheld for income taxes) (0.2) 37.24 Forfeited (0.1) 37.63 Outstanding at October 31, 2020 1.1 $ 36.32 At October 31, 2020, total unrecognized compensation cost, net of estimated forfeitures, related to RSUs was $25.2 million, which is expected to be recognized ratably over a weighted-average vesting period of 1.9 years. In 2020, 2019, and 2018, the weighted-average grant date fair value per share of awards granted was $36.11, $34.48, and $37.98, respectively. In 2020, 2019, and 2018, the total grant date fair value of RSUs vested and converted to shares of ABM common stock was $6.1 million, $10.7 million, and $7.4 million, respectively. Performance Shares, Including TSR Performance Shares Performance shares consist of a contingent right to receive shares of our common stock based on performance targets adopted by our Compensation Committee. Performance shares are credited with dividend equivalent rights that will be converted to performance shares at the fair market value of our common stock beginning after the performance targets have been satisfied and are subject to the same terms and conditions as the underlying award. For certain performance share awards, the number of performance shares that will vest is based on pre-established internal financial performance targets and typically a three-year service and performance period. The number of TSR awards and TSR-modified awards that will vest over the respective three-year performance period is based on our total shareholder return relative to the S&P 600 Small Cap Index for awards that were granted in 2018 and is based on the S&P 1500 Commercial Services & Supplies Index for awards that were granted in 2019 or 2020. Vesting of 0% to 150% of the awards originally granted may occur depending on the respective performance metrics under both award types. Performance Share Activity Number of Shares Weighted-Average Outstanding at October 31, 2019 0.8 $ 38.06 Granted 0.4 35.92 Vested (including 0.1 shares withheld for income taxes) (0.2) 37.72 Performance adjustments (0.1) 36.85 Forfeited (0.1) 36.58 Outstanding at October 31, 2020 0.8 $ 37.35 At October 31, 2020, total unrecognized compensation cost related to performance share awards was $14.4 million, which is expected to be recognized ratably over a weighted-average vesting period of 1.9 years. Except for TSR performance shares, these costs are based on estimated achievement of performance targets and estimated costs are periodically reevaluated. For our TSR performance shares, these costs are based on the fair value of awards at the grant date and are recognized on a straight-line basis over the service period of three years. In 2020, 2019, and 2018, the weighted-average grant date fair value per share of awards granted was $35.92, $35.44, and $38.53, respectively. In 2020, 2019, and 2018, the total grant date fair value of performance shares vested and converted to shares of ABM common stock was $6.1 million, $6.8 million, and $7.3 million, respectively. In 2020, 2019, and 2018, we used the Monte Carlo simulation valuation technique to estimate the fair value of TSR performance share grants, which used the assumptions in the table below. Monte Carlo Assumptions 2020 2019 2018 Expected life (1) 2.81 years 2.81 years 2.81 years Expected stock price volatility (2) 28.7 % 27.7 % 21.6 % Risk-free interest rate (3) 1.5 % 2.5 % 2.0 % Stock price (4) $ 37.99 $ 34.92 $ 39.02 (1) The expected life represents the remaining performance period of the awards. (2) The expected volatility for each grant is determined based on the historical volatility of our common stock over a period equal to the remaining term of the performance period from the date of grant for all awards. (3) The risk-free interest rate is based on the continuous compounded yield on U.S. Treasury Constant Maturity Rates with varying remaining terms; the yield is determined over a time period commensurate with the performance period from the grant date. (4) The stock price is the closing price of our common stock on the valuation date. Employee Stock Purchase Plan Years Ended October 31, (in millions, except per share amounts) 2020 2019 2018 Weighted-average fair value of granted purchase rights per share $ 1.75 $ 1.77 $ 1.70 Common stock issued 0.1 0.1 0.1 Fair value of common stock issued per share $ 33.18 $ 33.60 $ 32.34 Aggregate purchases $ 3.5 $ 4.1 $ 4.7

Income Taxes

Income Taxes	12 Months Ended
	Oct. 31, 2020
Income Tax Disclosure [Abstract]
Income Taxes	INCOME TAXES Geographic Sources of Income from Continuing Operations Before Income Taxes Years Ended October 31, (in millions) 2020 2019 2018 United States $ 45.2 $ 137.1 $ 94.8 Foreign 8.1 23.1 (7.1) Income from continuing operations before income taxes $ 53.3 $ 160.2 $ 87.7 Components of Income Tax (Provision) Benefit Years Ended October 31, (in millions) 2020 2019 2018 Current: Federal $ (59.3) $ (6.4) $ (4.3) State (28.6) (10.7) (7.3) Foreign (1.7) (5.9) (3.9) Deferred: Federal 23.2 (8.5) 21.8 State 12.5 (1.6) 0.2 Foreign 0.9 0.4 1.7 Income tax (provision) benefit $ (53.1) $ (32.7) $ 8.2 Reconciliation of the U.S. Statutory Tax Rate to Annual Effective Tax Rate Years Ended October 31, 2020 2019 2018 U.S. statutory rate 21.0 % 21.0 % 23.3 % State and local income taxes, net of federal tax benefit (0.6) 5.9 6.9 Federal and state tax credits (4.7) (3.9) (7.8) Impact of foreign operations 1.3 (1.0) 1.3 Changes in uncertain tax positions (2.0) (0.8) (6.7) Incremental tax benefit from share-based compensation awards (1.6) (0.7) (3.9) Energy efficiency incentives (3.8) — (3.2) Impact from goodwill impairment 81.7 — 4.4 Transition tax on foreign earnings — (1.1) 5.1 Remeasurement of U.S. deferred taxes — (0.3) (31.5) Nondeductible expenses 4.4 2.1 2.4 Other, net 3.9 (0.8) 0.3 Effective tax rate 99.6 % 20.4 % (9.4) % On December 22, 2017, the Tax Act was enacted into law. Among other provisions, it reduced the federal corporate income tax rate from 35% to 21% and required companies to pay a one-time transition tax on the deemed repatriation of indefinitely reinvested earnings of international subsidiaries. Our U.S. statutory federal tax rate for fiscal 2019 and future years was reduced to 21% from our blended rate of 23.3% in fiscal 2018. Other provisions under the Tax Act became effective for us in fiscal 2019, including limitations on deductibility of interest and executive compensation, as well as a new minimum tax on Global Intangible Low-Taxed Income (“GILTI”), which we have elected to account for as a period cost. During 2018, we finalized our analysis of the transitional impacts of the Tax Act. As a result, we recorded a one-time tax benefit of $29.6 million from the remeasurement of certain deferred tax assets and liabilities based on the new tax rates at which they are expected to reverse in the future. In addition, we recorded an expense of $4.5 million for the one-time transition tax on the deemed repatriation of indefinitely reinvested earnings of our international subsidiaries. Upon finalizing our tax filings, the impact of the transition tax was ultimately an expense of $2.7 million , which resulted in a benefit of $1.8 million that was recorded in the fourth quarter of 2019. We continue planning to reinvest our foreign earnings to fund future non-U.S. growth and expansion, and we do not anticipate remitting such earnings to the United States. While U.S. federal tax expense has been recognized as a result of the Tax Act, no deferred tax liabilities with respect to federal and state income taxes or foreign withholding taxes have been recognized. During 2020 and 2019, we had effective tax rates of 99.6% and 20.4%, respectively, resulting in a provision for tax of $53.1 million and $32.7 million, respectively. The effective tax rate for the year ended October 31, 2020, excluding a nondeductible impairment loss of $163.8 million, was 24.4%. Our effective tax rate for 2020 was also impacted by the following discrete items: a $5.7 million benefit from true-ups; a $2.3 million provision related to WOTC; a $2.1 million benefit from energy efficiency incentives; and a $1.1 million benefit from change of tax reserves. Our effective tax rate for 2019 was impacted by the following discrete items: a $1.8 million benefit from the transition tax (including foreign tax credits); a $1.7 million benefit from state true-ups; a $1.6 million benefit from federal true-ups; a $1.3 million provision related to WOTC; a $1.3 million benefit from expiring statutes of limitations; a $1.1 million benefit from the vesting of share-based compensation awards; and a $0.9 million benefit from research and development credits. Components of Deferred Tax Assets and Liabilities As of October 31, (in millions) 2020 2019 Deferred tax assets attributable to: Self-insurance claims (net of recoverables) $ 74.7 $ 83.6 Deferred and other compensation 28.6 25.6 Accounts receivable allowances 8.8 5.6 Settlement liabilities 5.0 3.1 Other accruals 1.5 1.8 Other comprehensive income 2.7 0.5 State taxes 1.4 0.4 State net operating loss carryforwards 5.9 11.2 Tax credits 3.7 6.3 Unrecognized tax benefits 3.2 3.0 Deferred payroll taxes 26.9 — Operating lease liabilities 38.2 — Gross deferred tax assets 200.6 141.2 Valuation allowance (4.1) (8.4) Total deferred tax assets 196.5 132.8 Deferred tax liabilities attributable to: Property, plant and equipment (1.2) (4.8) Goodwill and other acquired intangibles (159.4) (170.6) Right-of-use assets (38.2) — Other (8.5) (5.2) Total deferred tax liabilities (207.3) (180.6) Net deferred tax liabilities $ (10.8) $ (47.7) Net Operating Loss Carryforwards and Credits State net operating loss carryforwards totaling $102.3 million at October 31, 2020, are being carried forward in several state jurisdictions where we are permitted to use net operating losses from prior periods to reduce future taxable income. These losses will expire between 2021 and 2040. Federal net operating loss carryforwards were fully utilized during 2020. Federal and state tax credit carryforwards totaling $4.4 million are available to reduce future cash taxes and will expire between 2021 and 2040. The valuation allowance represents the amount of tax benefits related to state net operating loss carryforwards that are not likely to be realized. We believe the remaining deferred tax assets are more likely than not to be realizable based on estimates of future taxable income. Changes to the Valuation Allowance Years Ended October 31, (in millions) 2020 2019 2018 Valuation allowance at beginning of year $ 8.4 $ 12.0 $ 7.7 GCA acquisition — — 2.4 Other, net (4.3) (3.6) 1.8 Valuation allowance at end of year $ 4.1 $ 8.4 $ 12.0 Unrecognized Tax Benefits At October 31, 2020, 2019, and 2018, there were $35.5 million, $35.3 million, and $35.8 million, respectively, of unrecognized tax benefits that if recognized in the future would impact our effective tax rate. We estimate that a decrease in unrecognized tax benefits of up to approximately $0.6 million is reasonably possible over the next twelve months due to lapses of applicable statutes of limitations. At October 31, 2020 and 2019, accrued interest and penalties were $1.5 million and $1.2 million, respectively. For interest and penalties, we recognized an expense of $0.4 million and $0.2 million in 2020 and 2019, respectively, and a benefit of $1.0 million in 2018. Reconciliation of Total Unrecognized Tax Benefits Years Ended October 31, (in millions) 2020 2019 2018 Balance at beginning of year $ 35.3 $ 35.8 $ 53.4 Additions for tax positions related to the current year 2.1 — 0.2 Additions for tax positions related to prior years 1.6 3.6 — Reductions for tax positions related to prior years — — (9.0) Reductions for lapse of statute of limitations (3.0) (3.9) (8.7) Settlements (0.5) (0.3) (0.1) Balance at end of year $ 35.5 $ 35.3 $ 35.8 Jurisdictions We conduct business in all 50 states, significantly in California, Texas, and New York, as well as in various foreign jurisdictions. Our most significant income tax jurisdiction is the United States. Due to expired statutes and closed audits, our federal income tax returns for years prior to fiscal 2016 are no longer subject to examination by the U.S. Internal Revenue Service. Generally, for the majority of state and foreign jurisdictions where we do business, periods prior to fiscal 2016 are no longer subject to examination. We are currently being examined by the IRS and tax authorities of California, New York City, and Wisconsin.

Segment and Geographic Informat

Segment and Geographic Information	12 Months Ended
	Oct. 31, 2020
Segment Reporting [Abstract]
Segment and Geographic Information	SEGMENT AND GEOGRAPHIC INFORMATION Segment Information Our current reportable segments consist of B&I, T&M, Education, Aviation, and Technical Solutions, as further described below. REPORTABLE SEGMENTS AND DESCRIPTIONS B&I B&I, our largest reportable segment, encompasses janitorial, facilities services, and parking services for commercial real estate properties, sports and entertainment venues, and traditional hospitals and non-acute healthcare facilities. B&I also provides vehicle maintenance and other services to rental car providers. T&M T&M provides janitorial, facilities services, and parking services to industrial and high-tech manufacturing facilities. Education Education delivers janitorial, custodial, landscaping and grounds, facilities engineering, and parking services for public school districts, private schools, colleges, and universities. Aviation Aviation supports airlines and airports with services ranging from parking and janitorial to passenger assistance, catering logistics, air cabin maintenance, and transportation. Technical Solutions Technical Solutions specializes in mechanical and electrical services. These services can also be leveraged for cross-selling across all of our industry groups, both domestically and internationally. The accounting policies for our segments are the same as those disclosed within our significant accounting policies in Note 2, “Basis of Presentation and Significant Accounting Policies.” Our management evaluates the performance of each reportable segment based on its respective operating profit results, which include the allocation of certain centrally incurred costs. Corporate expenses not allocated to segments include certain CEO and other finance and human resource departmental expenses, certain information technology costs, share-based compensation, certain legal costs and settlements, restructuring and related costs, certain actuarial adjustments to self-insurance reserves, and direct acquisition costs. Management does not review asset information by segment, therefore we do not present assets in this note. Financial Information by Reportable Segment Years Ended October 31, (in millions) 2020 2019 2018 Revenues Business & Industry $ 3,157.8 $ 3,251.4 $ 3,268.4 Technology & Manufacturing 956.0 917.0 925.4 Education 808.8 847.4 856.7 Aviation 680.9 1,017.3 1,038.7 Technical Solutions 506.6 593.2 500.1 Elimination of inter-segment revenues (122.4) (127.7) (147.1) $ 5,987.6 $ 6,498.6 $ 6,442.2 Operating profit (loss) Business & Industry $ 253.7 $ 182.3 $ 157.9 Technology & Manufacturing 84.4 72.5 67.4 Education (1) (41.1) 39.0 44.1 Aviation (2) (59.6) 21.1 23.2 Technical Solutions (3) 9.5 55.4 21.8 Government Services (0.1) (0.1) (0.8) Corporate (146.9) (159.0) (168.8) Adjustment for income from unconsolidated affiliates, included in Aviation (2.2) (3.0) (3.2) Adjustment for tax deductions for energy efficient government (2.1) 0.1 (2.8) 95.7 208.3 138.6 Income from unconsolidated affiliates 2.2 3.0 3.2 Interest expense (44.6) (51.1) (54.1) Income from continuing operations before income taxes $ 53.3 $ 160.2 $ 87.7 Depreciation and amortization Business & Industry $ 18.9 $ 21.3 $ 23.6 Technology & Manufacturing 12.5 14.3 15.6 Education 33.8 37.3 37.5 Aviation 10.6 11.9 13.1 Technical Solutions 7.2 8.6 10.2 Corporate 13.5 13.9 12.4 $ 96.4 $ 107.4 $ 112.5 (1) Reflects impairment charges totaling $99.3 million on goodwill during the year ended October 31, 2020. (2) Reflects impairment charges totaling $61.1 million on goodwill and intangible assets during the year ended October 31, 2020. (3) Reflects impairment charges totaling $12.4 million on goodwill and intangible assets during the year ended October 31, 2020. Geographic Information Based on the Country in Which the Sale Originated (1) Years Ended October 31, (in millions) 2020 2019 2018 Revenues United States $ 5,625.1 $ 6,025.2 $ 5,997.4 All other countries 362.5 473.3 444.8 $ 5,987.6 $ 6,498.6 $ 6,442.2 (1) Substantially all of our long-lived assets are related to United States operations.

Selected Quarterly Financial Da

Selected Quarterly Financial Data (Unaudited)	12 Months Ended
	Oct. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data (Unaudited)	SELECTED QUARTERLY FINANCIAL DATA (UNAUDITED) Fiscal Quarter (in millions, except per share amounts) First Second Third Fourth Year Ended October 31, 2020 Revenues $ 1,612.9 $ 1,496.0 $ 1,394.1 $ 1,484.6 Gross profit 179.2 189.9 219.2 242.4 Income (loss) from continuing operations 27.9 (136.8) 56.0 53.1 Income from discontinued operations, net of taxes 0.1 — — — Net income (loss) $ 28.0 $ (136.8) (1) $ 56.0 $ 53.1 Net income (loss) per common share — Basic Income (loss) from continuing operations $ 0.42 $ (2.05) $ 0.84 $ 0.79 Income from discontinued operations — — — — Net income (loss) $ 0.42 $ (2.05) $ 0.84 $ 0.79 Net income (loss) per common share — Diluted Income (loss) from continuing operations $ 0.41 $ (2.05) $ 0.83 $ 0.78 Income from discontinued operations — — — — Net income (loss) $ 0.42 $ (2.05) (1) $ 0.83 $ 0.78 Year ended October 31, 2019 Revenues $ 1,607.9 $ 1,594.7 $ 1,647.9 $ 1,648.0 Gross profit 162.0 180.5 193.9 194.7 Income from continuing operations 13.0 29.9 36.5 48.1 (Loss) income from discontinued operations, net of taxes (0.1) (0.2) 0.2 (0.1) Net income $ 13.0 $ 29.7 $ 36.8 $ 47.9 Net income per common share — Basic Income from continuing operations $ 0.20 $ 0.45 $ 0.55 $ 0.72 Income from discontinued operations — — — — Net income $ 0.20 $ 0.45 $ 0.55 $ 0.72 Net income per common share — Diluted Income from continuing operations $ 0.20 $ 0.45 $ 0.55 $ 0.71 Income from discontinued operations — — — — Net income $ 0.19 $ 0.45 $ 0.55 $ 0.71 (1) Includes goodwill and asset impairment charges of $172.8 million, $170.6 million after tax, or $2.54 per diluted share.

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualifying Accounts	12 Months Ended
	Oct. 31, 2020
SEC Schedule, 12-09, Valuation and Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	SCHEDULE II—VALUATION AND QUALIFYING ACCOUNTS (in millions) Balance Charges to Write-offs (1) / Allowance Taken Balance Accounts receivable and sales allowances 2020 $ 22.4 96.3 (83.2) $ 35.5 2019 19.2 87.7 (84.6) 22.4 2018 25.5 57.4 (63.6) 19.2 (1) Write-offs are net of recoveries.

Basis of Presentation and Sig_2

Basis of Presentation and Significant Accounting Policies (Policies)	12 Months Ended
	Oct. 31, 2020
Accounting Policies [Abstract]
Basis of Presentation	The Financial Statements have been prepared in accordance with United States generally accepted accounting principles (“U.S. GAAP”) and with the rules and regulations of the SEC, specifically Regulation S-X and the instructions to Form 10-K. Unless otherwise indicated, all references to years are to our fiscal year, which ends on October 31.
Principles of Consolidation	The Financial Statements include the accounts of ABM and all of our consolidated subsidiaries. We account for ABM’s investments in unconsolidated affiliates under the equity method of accounting. We include the results of acquired businesses in the Consolidated Statements of Comprehensive (Loss) Income from their respective acquisition dates. All intercompany accounts and transactions have been eliminated in consolidation.
Use of Estimates	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.
Cash and Cash Equivalents	Cash and Cash EquivalentsWe consider all highly liquid securities with an original maturity of three months or less to be cash and cash equivalents. As part of our cash management system, we use “zero balance” accounts to fund our disbursements. Under this system, at the end of each day the bank balance is zero, while the book balance is usually a negative amount due to reconciling items, such as outstanding checks. We report the changes in these book cash overdrafts as cash flows from financing activities.
Trade Accounts Receivable and Allowance for Doubtful Accounts	Trade Accounts Receivable and Costs Incurred in Excess of Amounts Billed Trade accounts receivable arise from services provided to our clients and are usually due and payable on varying terms from receipt of the invoice to net ninety days, with the exception of certain Technical Solutions project receivables that may have longer collection periods. These receivables are recorded at the invoiced amount and normally do not bear interest. In addition, our trade accounts receivable include unbilled receivables, such as invoices for services that have been provided but are not yet billed. Costs incurred in excess of amounts billed arise from Technical Solutions project contracts that typically provide for a schedule of billings or invoices to the client based on our performance to date of specific tasks inherent in the fulfillment of our performance obligation(s). The schedules for such billings usually do not precisely match the schedule on which costs are incurred. As a result, revenues generally differ from amounts that can be billed or invoiced to the client at any point during the contract. Allowance for Doubtful Accounts
Sales Allowance	Sales AllowanceIn connection with our service contracts, we periodically issue credit memos to our clients that are recorded as a reduction in revenues and an increase to the allowance for billing adjustments. These credits can result from client vacancy discounts, job cancellations, property damage, and other items. We estimate our potential future losses on these client receivables based on an analysis of the historical rate of sales adjustments (credit memos, net of re-bills) and known or expected trends.
Investments in Unconsolidated Affiliates	Investments in Unconsolidated AffiliatesWe own non-controlling interests (generally 20% to 50%) in certain affiliated entities that predominantly provide facility solutions to governmental and commercial clients, primarily in the United States and the Middle East. We account for such investments under the equity method of accounting. We evaluate our equity method investments for impairment whenever events or changes in circumstances indicate that the carrying amounts of such investments may not be recoverable. An impairment loss is recognized to the extent that the estimated fair value of the investment is less than its carrying amount and we determine that the impairment is other-than-temporary.
Investments in Auction Rate Securities	Investments in Auction Rate Securities Our investments in auction rate securities are classified as available-for-sale. Accordingly, auction rate securities are presented at fair value with unrealized gains and losses recorded in accumulated other comprehensive (loss) income, net of tax es (“AOCL”). On a quarterly basis, we analyze all auction rate securities that have unrealized losses for impairment consideration and assess the intent to sell such securities. If such intent exists, impaired securities are considered other-than-temporarily impaired and we recognize the entire difference between the auction rate security’s amortized cost and its fair value in earnings. We also consider if we may be required to sell the securities prior to the recovery of amortized cost, which may trigger an impairment charge. If these securities are considered impaired, we assess whether the amortized costs of the securities can be recovered by reviewing several factors, including credit risks associated with the issuer. If we do not expect to recover the entire amortized cost of the security, we consider the security to be other-than-temporarily impaired and record the difference between the security’s amortized costs and its recoverable amount in earnings and the difference between the security’s amortized cost and fair value in AOCL
Property, Plant and Equipment	Property, Plant and Equipment We record property, plant and equipment at cost. Repairs and maintenance expenditures are expensed as incurred. In contrast, we capitalize major renewals or replacements that substantially extend the useful life of an asset. We determine depreciation for financial reporting purposes using the straight-line method over the following estimated useful lives: Category Years Computer equipment and software 3–5 Machinery and other equipment 3–5 Transportation equipment 1.5–10 Buildings 10–40 Furniture and fixtures 5 In addition, we depreciate assets under finance leases and leasehold improvements over the shorter of their estimated useful lives or the remaining lease term. Upon retirement or sale of an asset, we remove the cost and accumulated depreciation from our Consolidated Balance Sheets. When applicable, we record corresponding gains or losses within the accompanying Consolidated Statements of Comprehensive (Loss) Income.
Leases	Leases We enter into various noncancelable lease agreements for office space, parking facilities, warehouses, vehicles, and equipment used in the normal course of business. We determine if an arrangement is a lease at inception and begin recording lease activity at the commencement date, which is generally the date in which we take possession of or control the physical use of the asset. Right-of-use (“ROU”) assets and lease liabilities are recognized based on the present value of lease payments over the lease term with lease expense recognized on a straight-line basis. We use our incremental borrowing rate to determine the present value of future lease payments unless the implicit rate in a lease is readily determinable. Our incremental borrowing rate is the rate of interest we would have to pay to borrow on a collateralized basis over a similar term at an amount equal to the lease payments in a similar economic environment. This incremental borrowing rate is applied to the minimum lease payments within each lease agreement to determine the amounts of our ROU assets and lease liabilities. Our incremental borrowing rate as of November 1, 2019, was utilized for the initial measurement of operating lease liabilities upon adoption of Topic 842, as described below in “Recently Adopted Accounting Standards.” Our lease terms range from 1 to 30 years. Some leases include one or more options to renew, with renewal terms that can extend the lease term. We typically include options to extend the lease in a lease term when it is reasonably certain that we will exercise that option and when doing so is at our sole discretion. Certain equipment and vehicle leases may also include options to purchase the leased property. The depreciable life of assets and leasehold improvements are limited by the expected lease term unless there is a transfer of title or purchase option reasonably certain of exercise. Typically, if we decide to cancel or terminate a lease before the end of its term, we would owe the lessor the remaining lease payments under the term of such lease. Our lease agreements generally do not contain any material residual value guarantees or material restrictive covenants. We may rent or sublease certain real estate assets that we no longer use to third parties. Lease agreements may contain rent escalation clauses, rent holidays, or certain landlord incentives, including tenant improvement allowances. Prior to November 1, 2019, we recognized lease expense related to operating leases on a straight-line basis over the terms of the leases and, accordingly, recorded the difference between cash rent payments and recognition of rent expense as a deferred rent liability or prepaid rent. Landlord-funded leasehold improvements were also recorded as deferred rent liabilities and were amortized as a reduction of rent expense over the noncancelable term of the related operating lease. The ROU assets recognized upon adoption of Topic 842 include: cumulative prepaid or accrued rent on the adoption date, unamortized lease incentives, and unamortized initial direct costs initially recognized prior to adoption of Topic 842. Following adoption of Topic 842, ROU assets include amounts for scheduled rent increases and are reduced by lease incentive amounts. Certain of our lease agreements include variable rent payments, consisting primarily of rental payments adjusted periodically for inflation and amounts paid to the lessor based on cost or consumption, such as maintenance and utilities . These costs are expensed as incurred. Certain of our parking arrangements also contain variable rent payments that are a percentage of parking services revenue based on contractual levels. We record contingent rent as it becomes probable that specified targets will be met. Vari able rent lease components are not included in the lease liability. Service concession arrangements within the scope of ASU No. 2017-10, Service Concession Arrangements (Topic 853) : Determining the Customer of the Operation Services
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets Goodwill represents the excess purchase price of acquired businesses over the fair value of the assets acquired and liabilities assumed. We have elected to make the first day of our fourth quarter, August 1st, the annual impairment assessment date for goodwill. However, we could be required to evaluate the recoverability of goodwill more often if impairment indicators exist. Goodwill is tested for impairment at a “reporting unit” level by performing either a qualitative evaluation or a quantitative test. The qualitative evaluation is an assessment of factors to determine whether it is more likely than not that the fair value of a reporting unit is less than its carrying amount. We may elect not to perform the qualitative assessment for some or all reporting units and instead perform a quantitative test under which we estimate the fair value using a weighting of fair values derived from an income approach and a market approach. The discounted estimates of future cash flows include significant management assumptions, such as revenue growth rates, operating margins, weighted average cost of capital, and future economic and market conditions. Other intangible assets primarily consist of acquired customer contracts and relationships that are amortized using the sum-of-the-years’-digits method over their useful lives, consistent with the estimated useful life considerations used in the determination of their fair values. This accelerated method of amortization reflects the pattern in which the economic benefits from the intangible assets of customer contracts and relationships are expected to be realized. We amortize other non-customer acquired intangibles using a straight-line method of amortization. We evaluate other intangible assets, as well as our long-lived assets, for impairment whenever events or changes in circumstances indicate that the carrying amount of such assets may not be recoverable. When this occurs, a recoverability test is performed that compares the projected undiscounted cash flows from the use and eventual disposition of an asset or asset group to its carrying amount. If the projected undiscounted cash flows are less than the carrying amount, we calculate an impairment loss. The impairment loss calculation compares the fair value, which is based on projected discounted cash flows, to the carrying value.
Federal Energy Savings Performance Contract Receivables	Federal Energy Savings Performance Contract ReceivablesAs part of our Technical Solutions business, we enter into ESPCs with the federal government pursuant to which we agree to develop, design, engineer, and construct a project and to guarantee that the project will satisfy agreed-upon performance standards. ESPC receivables represent the amount to be paid by various federal government agencies for work we have satisfactorily performed under specific ESPCs. We assign certain of our rights to receive those payments to unaffiliated third parties that provide construction financing, which we record as a liability, for such contracts. This construction financing is recorded as cash flows from financing activities, while the use of the cash received to pay project costs under these arrangements is classified as operating cash flows. The ESPC receivable is recognized as revenue as each project is constructed. Upon completion and acceptance of the project by the government and upon satisfaction of true sale criteria, the assigned ESPC receivable from the government and corresponding ESPC liability are eliminated from our consolidated financial statements. Remaining Performance Obligations At October 31, 2020, performance obligations that were unsatisfied or partially unsatisfied for which we expect to recognize revenue totaled $266.3 million. We expect to recognize revenue on approximately 61% of the remaining performance obligations over the next 12 months, with the remainder recognized thereafter, based on our estimates of project timing. These amounts exclude variable consideration primarily related to: (i) contracts where we have determined that the contract consists of a series of distinct service periods and revenues are based on future performance that cannot be estimated at contract inception; (ii) parking contracts where we and the customer share the gross revenues or operating profit for the location; and (iii) contracts where transaction prices include performance incentives that are based on future performance and therefore cannot be estimated at contract inception. We apply the practical expedient that permits exclusion of information about the remaining performance obligations with original expected durations of one year or less.
Fair Value of Financial Instruments	Fair Value of Financial Instruments Fair value is the price we would receive to sell an asset or pay to transfer a liability in an orderly transaction with a market participant at the measurement date. In the absence of active markets for identical assets or liabilities, such measurements involve developing assumptions based on market observable data and, in the absence of such data, internal information that is consistent with what market participants would use in a hypothetical transaction that occurs at the measurement date. Observable inputs reflect market data obtained from independent sources, while unobservable inputs reflect our market assumptions. Preference is given to observable inputs. These two types of inputs create the following fair value hierarchy: Level 1 – Quoted prices for identical instruments in active markets; Level 2 – Quoted prices for similar instruments in active markets; quoted prices for identical or similar instruments in markets that are not active; and model-derived valuations whose inputs are observable or whose significant value drivers are observable; and Level 3 – Significant inputs to the valuation model are unobservable.
Insurance Reserves	Insurance Reserves We use a combination of insured and self-insurance programs to cover workers’ compensation, general liability, automobile liability, property damage, and other insurable risks. Insurance claim liabilities represent our estimate of retained risks without regard to insurance coverage. We retain a substantial portion of the risk related to certain workers’ compensation and medical claims. Liabilities associated with these losses include estimates of both filed claims and IBNR Claims. With the assistance of third-party actuaries, we periodically review our estimate of ultimate losses for IBNR Claims and adjust our required self-insurance reserves as appropriate. As part of this evaluation, we review the status of existing and new claim reserves as established by third-party claims administrators. The third-party claims administrators establish the case reserves based upon known factors related to the type and severity of the claims, demographic factors, legislative matters, and case law, as appropriate. We compare actual trends to expected trends and monitor claims developments. The specific case reserves estimated by the third-party administrators are provided to an actuary who assists us in projecting an actuarial estimate of the overall ultimate losses for our self-insured or high deductible programs, which includes the case reserves plus an actuarial estimate of reserves required for additional developments, such as IBNR Claims. We utilize the results of actuarial studies to estimate our insurance rates and insurance reserves for future periods and to adjust reserves, if appropriate, for prior years. In general, our insurance reserves are recorded on an undiscounted basis. We allocate current-year insurance expense to our operating segments based upon their underlying exposures, while actuarial adjustments related to prior year claims are recorded within Corporate expenses. We classify claims as current or long-term based on the expected settlement date. Estimated insurance recoveries related to recorded liabilities are reflected as assets in our Consolidated Balance Sheets when we believe the receipt of such amounts is probable.
Other Accrued Liabilities	Other Accrued LiabilitiesAt October 31, 2020 and 2019, other accrued liabilities primarily consisted of notes payable, other accrued expenses, legal fees and settlements, contract liabilities (which include deferred revenue and progress billings in excess of costs), employee benefits, unclaimed property, severance, insurance claims, rent payable, interest, and current finance leases.
Other Noncurrent Liabilities	Other Noncurrent LiabilitiesAt October 31, 2020 and 2019, other noncurrent liabilities primarily consisted of deferred payroll taxes, deferred rent, warranty reserves, ESPC liabilities, retirement plan liabilities, deferred compensation, and long-term finance leases.
Revenue Recognition	Revenue Recognition Beginning in fiscal 2019, we adopted ASU 2014-09, Revenue from Contracts with Customers (Topic 606) , and ASU 2017-10, Service Concession Arrangements (Topic 853) : Determining the Customer of the Operation Services . Prior period amounts have not been restated and continue to be reported in accordance with our historical accounting policies. Our revenue recognition policies under Topic 606 and Topic 853 are described in the following paragraphs, and references to our prior period policies are included below where they are substantially different. See Note 3, “Revenues,” for further information on our revenues. Contracts with Customers We account for a contract when it has approval and commitment from both parties, the rights of the parties are identified, payment terms are identified, the contract has commercial substance, and collectability of consideration is probable. Once a contract is identified, we evaluate whether it is a combined or single contract and whether it should be accounted for as more than one performance obligation. Generally, most of our contracts are cancelable by either party without a substantive penalty, and the majority of our contracts have a notification period of 30 to 60 days. If a contract includes a cancellation clause, the remaining contract term is limited to the required termination notice period. At contract inception, we assess the services promised to our customers and identify a performance obligation for each promise to transfer to the customer a service, or a bundle of services, that is distinct. To identify the performance obligation, we consider all of our services promised in the contract, regardless of whether they are explicitly stated or are implied by customary business practices. The majority of our contracts contain multiple promises that represent an integrated bundle of services comprised of activities that may vary over time; however, these activities fulfill a single integrated performance obligation since we perform a continuous service that is substantially the same and has the same pattern of transfer to the customer. Our performance obligations are primarily satisfied over time as we provide the related services. We allocate the contract transaction price to this single performance obligation and recognize revenue as the services are performed, as further described in “Contract Types” below. Certain arrangements involve variable consideration (primarily per transaction fees, reimbursable expenses, and sales-based royalties). We do not estimate the variable consideration for these arrangements; rather, we recognize these variable fees in the period they are earned. Some of our contracts, often related to Airline Services, may also include performance incentives based on variable performance measures that are ascertained exclusively by future performance and therefore cannot be estimated at contract inception and are recognized as revenue once known and mutually agreed upon. We include estimated amounts in the transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Our estimates of variable consideration and determination of whether to include estimated amounts in the transaction price are based largely on an assessment of our anticipated performance and all information (historical, current, and forecasted) that is reasonably available to us. We primarily account for our performance obligations under the series guidance, using the as-invoiced practical expedient when applicable. We apply the as-invoiced practical expedient to record revenue as the services are provided, given the nature of the services provided and the frequency of billing under the customer contracts. Under this practical expedient, we recognize revenue in an amount that corresponds directly with the value to the customer of our performance completed to date and for which we have the right to invoice the customer. We typically bill customers on a monthly basis and have the right to consideration from customers in an amount that corresponds directly with the performance obligation satisfied to date. The time between completion of the performance obligation and collection of cash is generally 30 to 60 days. Sales-based taxes are excluded from revenue. Contracts generally can be modified to account for changes in specifications and requirements. We consider contract modifications to exist when the modification either changes the consideration, creates new performance obligations, or changes the existing scope of the contract and related performance obligations. Historically, contract modifications have been for services that are not distinct from the existing contract, since we are providing a bundle of services that are highly interrelated, and are therefore treated as if they were part of that existing contract. Such modifications are generally accounted for prospectively as part of the existing contract. Contract Types We have arrangements under various contract types, as described below. Monthly Fixed-Price Monthly fixed-price arrangements are contracts in which the client agrees to pay a fixed fee every month over a specified contract term. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Square-Foot Square-foot arrangements are contracts in which the client agrees to pay a fixed fee every month based on the actual square footage serviced over a specified contract term. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Cost-Plus Cost-plus arrangements are contracts in which the clients reimburse us for the agreed-upon amount of wages and benefits, payroll taxes, insurance charges, and other expenses associated with the contracted work, plus a profit margin. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Work Orders Work orders generally consist of supplemental services requested by clients outside of the standard service specification and include cleanup after tenant moves, construction cleanup, flood cleanup, and snow removal. The nature of these short-term contracts involves performing one-off type services, and revenue is recognized at the agreed-upon contractual amount over time as the services are provided because the customer simultaneously receives and consumes the benefits of the services as they are performed. Transaction-Price Transaction-price contracts are arrangements in which customers are billed a fixed price for each transaction performed on a monthly basis (e.g., wheelchair passengers served, airplane cabins cleaned). We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Hourly Hourly arrangements are contracts in which the client is billed a fixed hourly rate for each labor hour provided. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual amount over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Management Reimbursement Under management reimbursement arrangements we manage a parking facility for a management fee and pass through the revenue and expenses associated with the facility to the owner. We measure progress toward satisfaction of the performance obligation over time as the services are provided. Under these contracts we recognize both revenues and expenses, in equal amounts, that are directly reimbursed from the property owner for operating expenses, as such expenses are incurred. Such revenues do not include gross customer collections at the managed locations because they belong to the property owners. We have determined we are the principal in these transactions, because the nature of our performance obligation is for us to provide the services on behalf of the customer and we have control of the promised services before they are transferred to the customer. Leased Location Under leased location parking arrangements we pay a fixed amount of rent, plus a percentage of revenues derived from monthly and transient parkers, to the property owner. We retain all revenues received and we are responsible for most operating expenses incurred. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. In accordance with Topic 853, rental expense and certain other expenses under contracts that meet the definition of service concession arrangements are now recorded as a reduction of revenue. Prior to November 1, 2018, such amounts were recorded as operating expenses. Allowance Under allowance parking arrangements we are paid a fixed amount or hourly rate to provide parking services, and we are responsible for certain operating expenses that are specified in the contract. We measure progress toward satisfaction of the performance obligation as the services are provided, and revenue is recognized at the agreed-upon contractual rate over time because the customer simultaneously receives and consumes the benefits of the services as they are performed. Energy Savings Contracts and Fixed-Price Repair and Refurbishment Under energy savings contracts and fixed-price repair and refurbishment arrangements we agree to develop, design, engineer, and construct a project. Additionally, as part of bundled energy solutions arrangements, we guarantee the project will satisfy agreed-upon performance standards. We use the cost-to-cost method, which compares the actual costs incurred to date with the current estimate of total costs to complete, to measure the satisfaction of the performance obligation and recognize revenue as work progresses and we incur costs on our contracts; we believe this method best reflects the transfer of control to the customer. This measurement and comparison process requires updates to the estimate of total costs to complete the contract, and these updates may include subjective assessments and judgments. Equipment purchased for these projects is project-specific and considered a value-added element to our work. Equipment costs are incurred when title is transferred to us, typically upon delivery to the work site. Revenue for uninstalled equipment is recognized at cost and the associated margin is deferred until installation is substantially complete. Prior to November 1, 2018, we recognized revenue and margin on uninstalled equipment consistent with other project costs under the percentage-of-completion method. We recognize revenue over time for all of our services as we perform them, because (i) control continuously transfers to the customer as work progresses or (ii) we have the right to bill the customer as costs are incurred. The customer typically controls the work in process as evidenced either by contractual termination clauses or by our rights to payment for work performed to date plus a reasonable profit to deliver products or services that do not have an alternative use to us. Certain project contracts include a schedule of billings or invoices to the customer based on our job-to-date percentage of completion of specific tasks inherent in the fulfillment of our performance obligation(s) or in accordance with a fixed billing schedule. Fixed billing schedules may not precisely match the actual costs incurred. Therefore, revenue recognized may differ from amounts that can be billed or invoiced to the customer at any point during the contract, resulting in balances that are considered revenue recognized in excess of cumulative billings or cumulative billings in excess of revenue recognized. Advanced payments from our customers generally do not represent a significant financing component as the payments are used to meet working capital demands that can be higher in the early stages of a contract, as well as to protect us from our customer failing to meet its obligations under the contract. Certain projects include service maintenance agreements under which existing systems are repaired and maintained for a specific period of time. We generally recognize revenue under these arrangements over time. Our service maintenance agreements are generally one-year renewable agreements. Franchise We franchise certain engineering services through individual and area franchises under the Linc Service and TEGG brands, which are part of ABM Technical Solutions. Initial franchise fees result from the sale of a franchise license and include the use of the name, trademarks, and proprietary methods. The franchise license is considered symbolic intellectual property, and revenue related to the sale of this right is recognized at the agreed-upon contractual amount over the term of the initial franchise agreement. Prior to November 1, 2018, initial fees from sales of franchise licenses were recognized in the year of sale. Royalty fee revenue consists of sales-based royalties received as part of the consideration for the franchise right, which is calculated as a percentage of the franchisees’ revenue. We recognize royalty fee revenue at the agreed-upon contractual rates over time as the customer revenue is generated by the franchisees. A receivable is recognized for an estimate of the unreported royalty fees, which are reported and remitted to us in arrears. Costs to Obtain a Contract With a Customer We capitalize the incremental costs of obtaining a contract with a customer, primarily commissions, as contract assets and recognize the expense on a straight-line basis over a weighted average expected customer relationship period. Capitalized commissions are classified as current or noncurrent based on the timing of when we expect to recognize the expense. Prior to November 1, 2018, such incremental costs were expensed as incurred. Contract Balances The timing of revenue recognition, billings, and cash collections results in contract assets and contract liabilities, as further explained below. The timing of revenue recognition may differ from the timing of invoicing to customers. If a contract includes a cancellation clause that allows for the termination of the contract by either party without a substantive penalty, the contract term is limited to the termination notice period. Contract assets primarily consist of billed trade receivables, unbilled trade receivables, and costs incurred in excess of amounts billed. Billed and unbilled trade receivables represent amounts from work completed in which we have an unconditional right to bill our customer. Costs incurred in excess of amounts billed typically arise when the revenue recognized on projects exceeds the amount billed to the customer. These amounts are transferred to billed trade receivables when the rights become unconditional. Contract assets also include the capitalization of incremental costs of obtaining a contract with a customer, primarily commissions. Contract liabilities consist of deferred revenue and advance payments and billings in excess of revenue recognized. We generally classify contract liabilities as current since the related contracts are generally for a period of one year or less. Contract liabilities decrease as we recognize revenue from the satisfaction of the related performance obligation.
Restructuring and Related Expenses, Severance and Other	Restructuring and Related Expenses Restructuring and related expenses include employee severance, external support fees, lease exit costs, and other costs. Our methodology to record these costs is described below. Severance As we do not have a past history of consistently providing severance benefits, we recognize severance costs for employees who do not have formal employment agreements when management has committed to a restructuring plan and communicated those actions to impacted employees, such that the employee is able to determine the type and amount of benefits that they will receive upon termination. In addition, if the employees are required to render service beyond the minimum retention period until they are terminated in order to receive the benefits, a liability is recognized ratably over the future service period. For employees with employment agreements, we accrue for these severance liabilities when it is probable that the impacted employee will be entitled to the benefits and the amount can be reasonably estimated. Other For other costs associated with exit and disposal activities, we recognize an expense at fair value in the period in which the liability is incurred.
Advertising	AdvertisingAdvertising costs are expensed as incurred.
Share-Based Compensation	Share-Based CompensationOur current share-based awards principally consist of restricted stock units (“RSUs”) and various performance share awards. We recognize compensation costs associated with these awards in selling, general and administrative expenses. For RSUs and certain performance share awards, the amount of compensation cost is measured based on the grant-date fair value of the equity instruments issued. Since our total shareholder return (“TSR”) performance share awards are performance awards with a market condition, the compensation costs associated with these awards are determined using a Monte Carlo simulation valuation model. For RSUs and TSR awards, compensation cost is recognized over the period that an employee provides service in exchange for the award. We recognize compensation cost associated with other performance share awards over the requisite service period based on the probability of achievement of performance criteria.
Taxes Collected from Clients and Remitted to Governmental Agencies	Taxes Collected from Clients and Remitted to Governmental Agencies We record taxes on client transactions due to governmental agencies as receivables and liabilities on the Consolidated Balance Sheets.
Net Income Per Common Share	Net Income Per Common ShareBasic net income per common share is net income divided by the weighted-average number of common shares outstanding during the period. Diluted net income per common share is based on the weighted-average number of common shares outstanding during the period, adjusted to include the potential dilution from the conversion of RSUs, vesting of performance shares, and exercise of stock options.
Contingencies and Litigation	Contingencies and LitigationWe are a party to a number of lawsuits, claims, and proceedings incident to the operation of our business, including those pertaining to labor and employment, contracts, personal injury, and other matters, some of which allege substantial monetary damages. Some of these actions may be brought as class actions on behalf of a class or purported class of employees. We accrue for loss contingencies when losses become probable and are reasonably estimable. If the reasonable estimate of the loss is a range and no amount within the range is a better estimate, the minimum amount of the range is recorded as a liability. We recognize legal costs as an expense in the period incurred.
Income Taxes	Income Taxes We account for income taxes using the asset and liability method. Deferred tax assets and liabilities are recognized for the future tax consequences attributable to temporary differences between the financial statement carrying amount of existing assets and liabilities and their respective tax bases. We measure deferred tax assets and liabilities using enacted tax rates expected to be applied to taxable income in the years in which those temporary differences are expected to be recovered. Deferred tax assets are reviewed for recoverability on a quarterly basis. A valuation allowance is recorded to reduce the carrying amount of a deferred tax asset to its realizable value unless it is more likely than not that such asset will be realized. We recognize accrued interest and penalties related to unrecognized tax benefits in income tax expense in our Consolidated Statements of Comprehensive (Loss) Income.
Recently Adopted and Issued Accounting Standards	Recently Adopted Accounting Standards Leases In February 2016, the Financial Accounting Standards Board (“FASB”) issued ASU 2016-02, Leases (Topic 842) . Since the release of ASU 2016-02, the FASB issued the following additional ASUs further updating Topic 842: • In January 2018, ASU 2018-01, Land Easement Practical Expedient for Transition to Topic 842 • In July 2018, ASU 2018-10, Codification Improvements to Topic 842 • In July 2018, ASU 2018-11, Leases (Topic 842): Targeted Improvements • In March 2019, ASU 2019-01, Leases (Topic 842): Codification Improvements Topic 842 replaced existing lease accounting guidance and was intended to provide enhanced transparency and comparability by requiring lessees to record most leases on the balance sheet. Under Topic 842, lessees are required to record on the balance sheet ROU assets (the right to use an underlying asset for the lease term) and the corresponding lease liabilities (the obligation to make lease payments arising from the lease). This guidance requires us to continue classifying leases as either operating or financing, with classification affecting the pattern of expense recognition in the Consolidated Statements of Comprehensive (Loss) Income. In addition, this new standard requires enhanced disclosures surrounding the amount, timing, and uncertainty of cash flows arising from leasing arrangements. We adopted Topic 842 on November 1, 2019 on a modified retrospective basis using the optional transition method permitted under ASU 2018-11 and have used this effective date as the initial application date. Comparative prior period Financial Statements have not been restated and continue to be reported under the accounting standards in effect for those prior periods presented. Upon adoption, we elected the package of transition practical expedients that allowed us to carry forward prior conclusions related to: (i) whether any expired or existing contracts are or contain leases; (ii) the lease classification for any expired or existing leases; and (iii) initial direct costs for existing leases. Additionally, we elected the practical expedient of not separating lease components from non-lease components for all asset classes. We also made an accounting policy election to not record ROU assets or lease liabilities for leases with an initial term of 12 months or less and will recognize payments for such leases in our Consolidated Statements of Comprehensive (Loss) Income on a straight-line basis over the lease term. We did not elect the use of hindsight for determining the reasonably certain lease term. The adoption of Topic 842 had a significant impact on our Consolidated Balance Sheet, but did not have a significant impact on our Consolidated Statement of Comprehensive (Loss) Income, our Consolidated Statement of Stockholders’ Equity, our Consolidated Statement of Cash Flows, our liquidity, or our compliance with the various covenants contained within our credit facility, as further described in Note 11, “Credit Facility.” The most significant impact was the recognition of ROU assets and lease liabilities for operating leases, while our accounting for finance leases remained substantially unchanged. See Note 4, “Leases,” for additional information on our lease arrangements. The impact of adoption of Topic 842 on our Consolidated Balance Sheet was as follows: (in millions) Balance at Adjustments Due Balance at ASSETS Right-of-use assets (1) $ — $ 167.5 $ 167.5 LIABILITIES AND STOCKHOLDERS’ EQUITY Current portion of lease liabilities (2) $ — $ 36.3 $ 36.3 Other accrued liabilities (3) 158.2 (3.0) 155.2 Long-term lease liabilities (4) — 154.2 154.2 Other noncurrent liabilities (5) 78.8 (20.0) 58.8 (1) Represents capitalization of operating lease assets and reclassification of prepaid rent, deferred rent, lease exit impairment liabilities, and lease incentives and tenant improvements on operating leases. (2) Represents the recognition of short-term operating lease liabilities. (3) Represents short-term deferred rent reclassified to ROU assets. (4) Represents the recognition of long-term operating lease liabilities. (5) Represents long-term deferred rent, lease incentives and tenant improvements, and lease exit impairment liabilities reclassified to ROU assets. In April 2020, the FASB issued a question and answer document focused on the application of lease accounting guidance to lease concessions provided relating to the Pandemic (the “Lease Modification Q&A”). The Lease Modification Q&A provides entities with the option to elect to account for lease concessions as though the enforceable rights and obligations existed in the original lease when the total cash flows resulting from the modified lease are substantially similar to the cash flows in the original lease. We have elected this practical expedient for Pandemic-related rent concessions, primarily rent deferrals or rent abatements, and we have elected not to remeasure the related lease liability and ROU asset for those leases. These concessions will be recognized as a reduction of rent expense in the month they occur. This election will continue while these concessions are in effect. Pandemic-related lease concessions were not material for the year ended October 31, 2020. Recently Issued Accounting Standards Measurement of Credit Losses of Financial Instruments In June 2016, the Financial Accounting Standards Board (“FASB”) issued ASU No. 2016-13, Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments . Since the release of ASU 2016-13, the FASB issued the following additional ASUs further updating Topic 326: • In November 2018, ASU 2018-19, Codification Improvements to Topic 326, Financial Instruments—Credit Losses • In April 2019, ASU 2019-04, Codification Improvements to Topic 326: Financial Instruments—Credit Losses; Topic 815: Derivatives and Hedging; and Topic 825: Financial Instruments • In May 2019, ASU 2019-05, Financial Instruments—Credit Losses (Topic 326): Targeted Transition Relief • In November 2019, ASU 2019-11, Codification Improvements to Topic 326, Financial Instruments—Credit Losses • In March 2020, ASU 2020-03, Codification Improvements to Financial Instruments Topic 326 replaces the existing incurred loss impairment model with a methodology that incorporates all expected credit loss estimates, resulting in more timely recognition of losses. Under Topic 326, an organization is required to measure all expected credit losses for financial assets held at the reporting date based on historical experience, current conditions, and reasonable and supportable forecasts that affect the collectability of the reported financial assets. It also requires credit losses related to available-for-sale debt securities to be recorded through an allowance for credit losses. We will adopt this standard effective November 1, 2020 on a modified retrospective basis. The adoption of the standard is not expected to have a material impact on the consolidated financial statements. Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract In August 2018, the FASB issued ASU No. 2018-15, Intangibles—Goodwill and Other-Internal-Use Software (Subtopic 350-40): Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract . This accounting update aligns the requirements for capitalizing implementation costs incurred in a hosting arrangement that is a service contract with the requirements for capitalizing implementation costs incurred to develop or obtain internal-use software. The guidance also specifies that the balance sheet, income statement, and statement of cash flows presentation of capitalized implementation costs and the related amortization should align with the presentation of the hosting (service) element of the arrangement. We will adopt this standard effective November 1, 2020 on a prospective basis. The adoption of the standard is not expected to have a material impact on the consolidated financial statements.

Basis of Presentation and Sig_3

Basis of Presentation and Significant Accounting Policies (Tables)	12 Months Ended
	Oct. 31, 2020
Accounting Policies [Abstract]
Schedule of Estimated Useful Lives of Property, Plant and Equipment	We determine depreciation for financial reporting purposes using the straight-line method over the following estimated useful lives: Category Years Computer equipment and software 3–5 Machinery and other equipment 3–5 Transportation equipment 1.5–10 Buildings 10–40 Furniture and fixtures 5
Schedule of Management Reimbursement Revenue by Segment	Years Ended October 31, (in millions) 2020 2019 2018 Business & Industry $ 221.4 $ 283.1 $ 276.6 Aviation 74.3 95.5 99.9 Total $ 295.6 $ 378.7 $ 376.4
Schedule of New Accounting Pronouncements and Changes in Accounting Principles	The impact of adoption of Topic 842 on our Consolidated Balance Sheet was as follows: (in millions) Balance at Adjustments Due Balance at ASSETS Right-of-use assets (1) $ — $ 167.5 $ 167.5 LIABILITIES AND STOCKHOLDERS’ EQUITY Current portion of lease liabilities (2) $ — $ 36.3 $ 36.3 Other accrued liabilities (3) 158.2 (3.0) 155.2 Long-term lease liabilities (4) — 154.2 154.2 Other noncurrent liabilities (5) 78.8 (20.0) 58.8 (1) Represents capitalization of operating lease assets and reclassification of prepaid rent, deferred rent, lease exit impairment liabilities, and lease incentives and tenant improvements on operating leases. (2) Represents the recognition of short-term operating lease liabilities. (3) Represents short-term deferred rent reclassified to ROU assets. (4) Represents the recognition of long-term operating lease liabilities. (5) Represents long-term deferred rent, lease incentives and tenant improvements, and lease exit impairment liabilities reclassified to ROU assets.

Revenues (Tables)

Revenues (Tables)	12 Months Ended
	Oct. 31, 2020
Revenue from Contract with Customer [Abstract]
Revenue from External Customers by Major Service Lines and Segments	Year Ended October 31, 2020 (in millions) B&I T&M Education Aviation Technical Solutions Total Major Service Line Janitorial (1) $ 2,420.4 $ 770.9 $ 716.5 $ 121.2 $ — $ 4,029.0 Parking (2) 362.8 33.5 1.8 255.9 — 654.0 Facility Services (3) 374.1 151.6 90.5 31.6 — 647.9 Building & Energy Solutions (4) — — — — 506.6 506.6 Airline Services (5) 0.4 — — 272.2 — 272.6 $ 3,157.8 $ 956.0 $ 808.8 $ 680.9 $ 506.6 $ 6,110.0 Elimination of inter-segment revenues (122.4) Total $ 5,987.6 Year Ended October 31, 2019 (in millions) B&I T&M Education Aviation Technical Solutions Total Major Service Line Janitorial (1) $ 2,316.1 $ 739.7 $ 756.3 $ 125.8 $ — $ 3,937.9 Parking (2) 511.5 25.9 3.1 335.3 — 875.8 Facility Services (3) 423.1 151.4 88.0 72.1 — 734.6 Building & Energy Solutions (4) — — — — 593.2 593.2 Airline Services (5) 0.6 0.1 — 484.1 — 484.8 $ 3,251.4 $ 917.0 $ 847.4 $ 1,017.3 $ 593.2 $ 6,626.3 Elimination of inter-segment revenues (127.7) Total $ 6,498.6 (1) Janitorial arrangements provide a wide range of essential cleaning services for commercial office buildings, airports and other transportation centers, educational institutions, government buildings, health facilities, industrial buildings, retail stores, and stadiums and arenas. These arrangements are often structured as monthly fixed-price, square-foot, cost-plus, and work order contracts. (2) Parking arrangements provide parking and transportation services for clients at various locations, including airports and other transportation centers, commercial office buildings, educational institutions, health facilities, hotels, and stadiums and arenas. These arrangements are structured as management reimbursement, leased location, and allowance contracts. Certain of these arrangements are considered service concession agreements and are accounted for under the guidance of Topic 853; accordingly, rent expense related to these arrangements is recorded as a reduction of the related parking service revenues. (3) Facility Services arrangements provide onsite mechanical engineering and technical services and solutions relating to a broad range of facilities and infrastructure systems that are designed to extend the useful life of facility fixed assets, improve equipment operating efficiencies, reduce energy consumption, lower overall operational costs for clients, and enhance the sustainability of client locations. These arrangements are generally structured as monthly fixed-price, cost-plus, and work order contracts. (4) Building & Energy Solutions arrangements provide custom energy solutions, electrical, HVAC, lighting, and other general maintenance and repair services for clients in the public and private sectors and are generally structured as Energy Savings and Fixed-Price Repair and Refurbishment contracts. We also franchise certain operations under franchise agreements relating to our Linc Network and TEGG brands pursuant to franchise contracts. (5) Airline Services arrangements support airlines and airports with services such as passenger assistance, catering logistics, and airplane cabin maintenance. These arrangements are often structured as monthly fixed-price, cost-plus, transaction price, and hourly contracts.
Contract with Customer, Asset and Liability	The following tables present the balances in our contract assets and contract liabilities: (in millions) October 31, 2020 October 31, 2019 Contract assets Billed trade receivables (1) $ 835.8 $ 978.7 Unbilled trade receivables (1) 53.9 56.9 Costs incurred in excess of amounts billed (2) 52.2 72.6 Capitalized commissions (3) 25.2 21.8 (1) Included in trade accounts receivable, net, on the Consolidated Balance Sheets. The fluctuations correlate directly to the execution of new customer contracts and to invoicing and collections from customers in the normal course of business. (2) Fluctuation is primarily due to the timing of payments on our contracts measured using the cost-to-cost method of revenue recognition. (3) Included in other current assets and other noncurrent assets on the Consolidated Balance Sheets. During the year ended October 31, 2020, we capitalized $16.4 million of new costs and amortized $13.0 million of previously capitalized costs. There was no impairment loss recorded on the costs capitalized. (in millions) Year Ended Contract liabilities (1) Balance at beginning of year $ 38.0 Additional contract liabilities 315.5 Recognition of deferred revenue (317.1) Balance at end of year $ 36.4

Leases (Tables)

Leases (Tables)	12 Months Ended
	Oct. 31, 2020
Leases [Abstract]
Supplemental Balance Sheet Information	The components of lease assets and liabilities and their classification on our Consolidated Balance Sheets as of October 31, 2020 were as follows: Balance at (in millions) Classification October 31, 2020 Lease assets Operating leases Right-of-use assets $ 143.1 Finance leases Property, plant and equipment, net (1) 6.1 Total lease assets $ 149.2 Lease liabilities Current liabilities Operating leases Current portion of lease liabilities $ 35.0 Finance leases Other accrued liabilities 2.3 Noncurrent liabilities Operating leases Long-term lease liabilities 131.4 Finance leases Other noncurrent liabilities 2.8 Total lease liabilities $ 171.4 The following table includes the weighted-average remaining lease terms, in years, and the weighted-average discount rate used to calculate the present value of operating lease liabilities: As of October 31, 2020 Weighted-average remaining lease term (years) Operating leases 6.1 Finance leases 2.0 Weighted-average discount rate Operating leases 4.14 % Finance leases 4.55 %
Lease, Cost	The components of lease costs and classification within the Consolidated Statements of Comprehensive (Loss) Income were as follows: (in millions) Year Ended Operating lease costs: Operating expenses (1)(2) $ 67.9 Selling, general and administrative expenses (3) 28.5 Finance lease costs: Operating expenses (4) 3.5 Interest expense (5) 0.5 Total lease costs $ 100.4 (1) Related to certain parking arrangements. (2) Includes short-term lease costs and variable lease costs. (3) Includes short-term lease costs. (4) Represents amortization of leased assets. (5) Interest on lease liabilities. The following table presents information on short-term and variable lease costs: (in millions) Year Ended Short-term lease costs $ 47.0 Variable lease costs 3.5 Total short-term and variable lease costs $ 50.5 The following table includes supplemental cash and non-cash information related to operating leases: (in millions) Year Ended Cash paid for amounts included in the measurement of lease liabilities Operating cash flows from operating leases $ 44.8 Operating cash flows from finance leases 0.5 Financing cash flows from finance leases 3.4 Lease assets obtained in exchange for new operating lease liabilities (1) 15.7
Maturities of Operating Lease Liabilities	The amounts of future undiscounted cash flows related to the lease payments over the lease terms and the reconciliation to the present value of the lease liabilities as recorded on our Consolidated Balance Sheets as of October 31, 2020 are as follows: (in millions) Operating Finance Total Fiscal 2021 $ 41.3 $ 3.3 $ 44.6 Fiscal 2022 34.3 1.7 36.0 Fiscal 2023 29.2 0.9 30.1 Fiscal 2024 24.1 — 24.1 Fiscal 2025 18.2 — 18.2 Thereafter 43.3 — 43.3 Total lease payments 190.4 5.9 196.3 Less: imputed interest 24.0 0.8 24.9 Present value of lease liabilities $ 166.4 $ 5.1 $ 171.4 The amounts of minimum future commitments under non-cancelable operating and capital leases as of October 31, 2019, in accordance with Topic 840 were as follows: (in millions) Operating and Other (1) Capital Total Fiscal 2020 $ 42.8 $ 3.1 $ 45.9 Fiscal 2021 35.5 2.5 38.0 Fiscal 2022 30.3 1.3 31.6 Fiscal 2023 25.6 0.6 26.2 Fiscal 2024 20.5 — 20.5 Thereafter 51.8 — 51.8 Total (2) $ 206.5 $ 7.5 $ 214.0 (1) Includes total estimated sublease rental income of $15.8 million.
Maturities of Finance Lease Liabilities	The amounts of future undiscounted cash flows related to the lease payments over the lease terms and the reconciliation to the present value of the lease liabilities as recorded on our Consolidated Balance Sheets as of October 31, 2020 are as follows: (in millions) Operating Finance Total Fiscal 2021 $ 41.3 $ 3.3 $ 44.6 Fiscal 2022 34.3 1.7 36.0 Fiscal 2023 29.2 0.9 30.1 Fiscal 2024 24.1 — 24.1 Fiscal 2025 18.2 — 18.2 Thereafter 43.3 — 43.3 Total lease payments 190.4 5.9 196.3 Less: imputed interest 24.0 0.8 24.9 Present value of lease liabilities $ 166.4 $ 5.1 $ 171.4 The amounts of minimum future commitments under non-cancelable operating and capital leases as of October 31, 2019, in accordance with Topic 840 were as follows: (in millions) Operating and Other (1) Capital Total Fiscal 2020 $ 42.8 $ 3.1 $ 45.9 Fiscal 2021 35.5 2.5 38.0 Fiscal 2022 30.3 1.3 31.6 Fiscal 2023 25.6 0.6 26.2 Fiscal 2024 20.5 — 20.5 Thereafter 51.8 — 51.8 Total (2) $ 206.5 $ 7.5 $ 214.0 (1) Includes total estimated sublease rental income of $15.8 million.

Restructuring and Related Cos_2

Restructuring and Related Costs (Tables)	12 Months Ended
	Oct. 31, 2020
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Liabilities	Rollforward of Restructuring and Related Liabilities (in millions) External Support Fees Employee Severance Other Project Fees Lease Exit Costs Asset Impairment Total Balance, October 31, 2017 $ 2.5 $ 2.7 $ 0.4 $ 2.8 $ — $ 8.4 Costs recognized (1) 4.0 11.0 8.2 2.0 0.6 25.7 Payments (6.5) (9.9) (6.7) (1.5) — (24.7) Non-cash items — — — (0.2) (0.6) (0.7) Balance, October 31, 2018 $ — $ 3.8 $ 1.8 $ 3.1 $ — $ 8.6 Costs recognized (1) 1.5 4.6 4.5 0.7 — 11.2 Payments (1.0) (5.3) (5.6) (1.1) — (12.9) Balance, October 31, 2019 $ 0.5 $ 3.0 $ 0.7 $ 2.7 $ — $ 7.0 Costs recognized (1) 1.4 0.3 3.2 2.7 — 7.6 Payments (1.9) (2.0) (3.7) (0.2) — (7.9) Non-cash items — — (0.2) (5.3) — (5.4) Balance, October 31, 2020 $ — $ 1.3 $ — $ — $ — $ 1.3 (1) We include these costs within corporate expenses. Cumulative Restructuring and Related Charges (in millions) External Support Fees Employee Severance Other Project Fees Lease Exit Costs Asset Impairment Total GCA and Other $ 4.9 $ 18.3 $ 15.5 $ 3.4 $ — $ 42.2 2020 Vision 30.0 13.0 10.7 7.7 5.2 66.5 Total $ 34.9 $ 31.3 $ 26.2 $ 11.1 $ 5.2 $ 108.7

Net Income Per Common Share (Ta

Net Income Per Common Share (Tables)	12 Months Ended
	Oct. 31, 2020
Earnings Per Share [Abstract]
Schedule of Basic and Diluted Net Income Per Common Share Calculations	Basic and Diluted Net Income Per Common Share Calculations Years Ended October 31, (in millions, except per share amounts) 2020 2019 2018 Income from continuing operations $ 0.2 $ 127.5 $ 95.9 Income (loss) from discontinued operations, net of taxes 0.1 (0.1) 1.8 Net income $ 0.3 $ 127.4 $ 97.8 Weighted-average common and common equivalent 66.9 66.6 66.1 Effect of dilutive securities RSUs 0.1 0.2 0.1 Stock options 0.1 0.1 0.1 Performance shares 0.1 0.1 — Weighted-average common and common equivalent 67.3 66.9 66.4 Net income per common share — Basic Income from continuing operations $ 0.00 $ 1.92 $ 1.45 Income from discontinued operations — — 0.03 Net income $ 0.00 $ 1.91 $ 1.48 Net income per common share — Diluted Income from continuing operations $ 0.00 $ 1.91 $ 1.45 Income from discontinued operations — — 0.03 Net income $ 0.00 $ 1.90 $ 1.47
Schedule of Anti-Dilutive Outstanding Stock Awards Issued Under Share-Based Compensation Plans	Anti-Dilutive Outstanding Stock Awards Issued Under Share-Based Compensation Plans Years Ended October 31, (in millions) 2020 2019 2018 Anti-dilutive 0.4 0.3 0.4

Fair Value of Financial Instr_2

Fair Value of Financial Instruments (Tables)	12 Months Ended
	Oct. 31, 2020
Fair Value Disclosures [Abstract]
Schedule of Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis	Fair Value Hierarchy of Our Financial Instruments Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis As of October 31, (in millions) Fair Value Hierarchy 2020 2019 Cash and cash equivalents (1) 1 $ 394.2 $ 58.5 Insurance deposits (2) 1 0.7 0.8 Assets held in funded deferred compensation plan (3) 1 2.6 2.5 Credit facility (4) 2 725.3 808.4 Interest rate swap liabilities (5) 2 15.5 14.6 Investments in auction rate securities (6) 3 — 5.0 (1) Cash and cash equivalents are stated at nominal value, which equals fair value. (2) Represents restricted deposits that are used to collateralize our insurance obligations and are stated at nominal value, which equals fair value. These insurance deposits are included in “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. See Note 10, “Insurance,” for further information. (3) Represents investments held in a Rabbi trust associated with one of our deferred compensation plans, which we include in “Other noncurrent assets” on the accompanying Consolidated Balance Sheets. The fair value of the assets held in the funded deferred compensation plan is based on quoted market prices. See Note 12, “Employee Benefit Plans,” for further information. (4) Represents gross outstanding borrowings under our syndicated line of credit and term loan. Due to variable interest rates, the carrying value of outstanding borrowings under our line of credit and term loan approximates the fair value. See Note 11, “Credit Facility,” for further information. (5) Represents interest rate swap derivatives designated as cash flow hedges. The fair values of the interest rate swaps are estimated based on the present value of the difference between expected cash flows calculated at the contracted interest rates and the expected cash flows at current market interest rates using observable benchmarks for the London Interbank Offered Rate (“LIBOR”) forward rates at the end of the period. At October 31, 2020 and 2019, our interest rate swaps are included in “Other noncurrent liabilities” on the accompanying Consolidated Balance Sheets. See Note 11, “Credit Facility,” for further information. (6) The fair value of investments in auction rate securities is based on discounted cash flow valuation models, primarily utilizing unobservable inputs, including assumptions about the underlying collateral, credit risks associated with the issuer, credit enhancements associated with financial insurance guarantees, and the possibility of the security being refinanced by the issuer or having a successful auction. At October 31, 2019, we held an investment in one auction rate security that had an original principal amount, amortized cost, and fair value of $5.0 million that was included in “Other investments” on the accompanying Consolidated Balance Sheets. During the first quarter of 2020, this auction rate security was called by the issuer, and we received proceeds for the fair value of this debt instrument of $5.0 million. There were no unrealized gains or losses on this auction rate security included in AOCL. At October 31, 2020, we had no investments in auction rate securities.

Property, Plant and Equipment (

Property, Plant and Equipment (Tables)	12 Months Ended
	Oct. 31, 2020
Property, Plant and Equipment [Abstract]
Schedule of Property, Plant and Equipment	Property, Plant and Equipment As of October 31, (in millions) 2020 2019 Machinery and other equipment $ 137.0 $ 118.8 Computer equipment and software 101.2 91.7 Transportation equipment 57.7 57.4 Leasehold improvements 57.1 59.5 Furniture and fixtures 13.7 13.1 Buildings 7.6 8.2 Land 0.7 1.0 375.0 349.8 Less: Accumulated depreciation (1) 241.3 199.5 Total $ 133.7 $ 150.3 (1) For 2020, 2019, and 2018, depreciation expense was $48.0 million, $48.9 million, and $46.5 million, respectively.
Schedule of Capital Leases Included in Property, Plant and Equipment	Finance Leases Included in Property, Plant and Equipment As of October 31, (in millions) 2020 2019 Transportation equipment $ 19.4 $ 20.0 Furniture and fixtures 0.2 0.2 Machinery and other equipment — 0.3 Computer equipment and software — 0.1 19.7 20.6 Less: Accumulated depreciation 13.6 10.7 Total $ 6.1 $ 9.9

Goodwill and Other Intangible_2

Goodwill and Other Intangible Assets (Tables)	12 Months Ended
	Oct. 31, 2020
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill Activity and Carrying Amount by Segment	Goodwill (in millions) Business & Industry Technology & Manufacturing Education Aviation Technical Solutions Healthcare Total Balance at October 31, 2018 $ 527.9 $ 407.2 $ 557.4 $ 124.9 $ 158.7 $ 58.7 $ 1,834.8 Reallocation (1) 45.7 — 1.2 — 11.8 (58.7) — Foreign currency translation 0.3 — — 0.1 0.3 — 0.6 Balance at October 31, 2019 $ 573.9 $ 407.2 $ 558.6 $ 125.0 $ 170.7 $ — $ 1,835.4 Foreign currency translation 0.1 — — — (0.3) — (0.2) Impairment loss (2) — — (99.3) (55.5) (9.0) (163.8) Balance at October 31, 2020 $ 574.0 $ 407.2 $ 459.3 $ 69.5 $ 161.5 $ — $ 1,671.4 (1) Goodwill associated with our Healthcare business was reallocated in connection with the reorganization of this business during the third quarter of 2019. (2) The impairment charge is included in “Impairment loss” on our Consolidated Statements of Comprehensive (Loss) Income for the year ended October 31, 2020, and is not tax deductible.
Significant Assumptions Used to Determine Fair Value of Auction Rate Securities	The discount rates utilized in the income approach valuation method are summarized in the table below. Discount Education 10.0% Aviation 10.5% Technical Solutions 11.0%
Schedule of Other Intangible Assets	Other Intangible Assets October 31, 2020 October 31, 2019 (in millions) Gross Carrying Amount Accumulated Amortization Total Gross Carrying Amount Accumulated Amortization Total Customer contracts and relationships (1) $ 573.1 $ (333.6) $ 239.6 $ 595.9 $ (298.9) $ 297.0 Trademarks and trade names 9.8 (9.8) — 9.8 (9.8) 0.1 Contract rights and other 0.5 (0.4) 0.1 0.5 (0.4) 0.1 Total (2) $ 583.5 $ (343.8) $ 239.7 $ 606.2 $ (309.0) $ 297.2 (1) Reflects a net impairment charge of $9.0 million recorded in 2020 as a result of the triggering event described above. We recognized net impairment charges of $5.6 million related to Aviation (consisting of a $13.8 million reduction in the gross carrying amount of the underlying customer relationships less $8.2 million of accumulated amortization) and $3.4 million related to our U.K. Technical Solutions business (consisting of an $8.7 million reduction in the gross carrying amount of the underlying customer relationships less $5.3 million of accumulated amortization). These impairment charges are included in “Impairment loss” on our Consolidated Statements of Comprehensive (Loss) Income for the year ended October 31, 2020. We did not record impairment charges on other intangible assets during 2019.
Schedule of Estimated Annual Amortization Expense	Estimated Annual Amortization Expense For Each of the Next Five Years (in millions) 2021 2022 2023 2024 2025 Estimated amortization expense (1) $ 42.1 $ 36.8 $ 32.2 $ 28.0 $ 23.9 (1) These amounts could vary as acquisitions of additional intangible assets occur in the future.

Insurance (Tables)

Insurance (Tables)	12 Months Ended
	Oct. 31, 2020
Insurance [Abstract]
Schedule of Insurance Related Balances and Activity	Insurance Related Balances and Activity (in millions) October 31, 2020 October 31, 2019 Insurance claim reserves, excluding medical and dental $ 504.9 $ 507.8 Medical and dental claim reserves 16.6 7.2 Insurance recoverables 70.1 64.5
Schedule of Casualty Program Insurance Reserves Rollforward	Casualty Program Insurance Reserves Rollforward Years Ended October 31, (in millions) 2020 2019 2018 Net balance at beginning of year $ 443.3 $ 427.7 $ 412.5 Change in case reserves plus IBNR Claims — current year 128.5 137.9 131.4 Change in case reserves plus IBNR Claims — prior years (30.2) (3.4) 10.2 Claims paid (106.8) (119.1) (126.5) GCA acquisition 0.2 — 0.1 Net balance, October 31 (1) 434.8 443.3 427.7 Recoverables 70.1 64.5 73.7 Gross balance, October 31 $ 504.9 $ 507.8 $ 501.4
Schedule of Instruments Used to Collateralize Insurance Obligations	Instruments Used to Collateralize Our Insurance Obligations As of October 31, (in millions) 2020 2019 Standby letters of credit $ 143.6 $ 141.0 Surety bonds 82.6 90.8 Restricted insurance deposits 0.7 0.8 Total $ 226.9 $ 232.6

Credit Facility (Tables)

Credit Facility (Tables)	12 Months Ended
	Oct. 31, 2020
Debt Disclosure [Abstract]
Schedule of Credit Facility Information	Credit Facility Information (in millions) October 31, 2020 October 31, 2019 Current portion of long-term debt Gross term loan $ 120.0 $ 60.0 Unamortized deferred financing costs (3.3) (2.8) Current portion of term loan $ 116.7 $ 57.2 Long-term debt Gross term loan $ 560.0 $ 680.0 Unamortized deferred financing costs (2.3) (4.1) Total noncurrent portion of term loan 557.7 675.9 Revolving line of credit (1)(2) 45.3 68.4 Long-term debt $ 603.0 $ 744.2 (1) Standby letters of credit amounted to $153.1 million at October 31, 2020. (2) At October 31, 2020, we had borrowing capacity of $596.6 million, reflecting covenant restrictions.
Schedule of Term Loan Maturities	Term Loan Maturities During 2020, we made principal payments under the term loan of $60.0 million. As of October 31, 2020, the following principal payments are required under the term loan. (in millions) 2021 2022 Debt maturities $ 120.0 $ 560.0
Schedule of Interest Rate Information	Notional Amount Fixed Interest Rate Effective Date Maturity Date $ 90.0 million 2.83% November 1, 2018 April 30, 2021 $ 90.0 million 2.84% November 1, 2018 October 31, 2021 $ 130.0 million 2.86% November 1, 2018 April 30, 2022 $ 130.0 million 2.84% November 1, 2018 September 1, 2022

Employee Benefit Plans (Tables)

Employee Benefit Plans (Tables)	12 Months Ended
	Oct. 31, 2020
Retirement Benefits [Abstract]
Schedule of Information for the Plans	Information for the Plans As of October 31, (in millions) 2020 2019 Net obligations $ 9.6 $ 8.4 Projected benefit obligations 17.0 16.1 Fair value of assets 7.4 7.8
Schedule of Multiemployer Pension Plans	Key Information for Individually Significant Multiemployer Defined Benefit Pension Plans (1) ($ in millions) Pension Protection Act Zone Status (3) FIP/RP Status (4) Contributions by ABM Surcharge Imposed (5) Expiration Dates of Collective Bargaining Agreements Pension Fund EIN/PN (2) 2020 2019 Pending/ 2020 2019 2018 Building Service 32BJ Pension Fund 13-1879376 / 001 Red 6/30/2019 Red Implemented $ 16.8 $ 19.3 $ 19.9 No 10/15/2023 – 12/31/2023 S.E.I.U. National Industry Pension Fund 52-6148540 / 001 Red 12/31/2019 Red Implemented 11.1 10.6 8.7 Yes 6/30/2021 – Central Pension Fund of the IUOE & Participating Employers 36-6052390 / 001 Green 1/31/2020 Green N/A* 7.1 11.7 11.0 N/A* 4/30/2021 – 12/31/2022 SEIU Local 1 & Participating Employers Pension Trust 36-6486542 / 001 Green 9/30/2019 Green N/A* 4.3 5.1 5.8 N/A* 4/4/2021 IUOE Stationary Engineers Local 39 Pension Plan 94-6118939 / 001 Green 12/31/2019 Green N/A* 4.3 4.6 5.2 N/A* 11/15/2020 – 10/31/2024 Western Conference of Teamsters Pension Plan 91-6145047 / 001 Green 12/31/2019 Green N/A* 2.5 3.1 3.1 N/A* 6/30/2021 – All Other Plans: 9.5 12.2 11.5 Total Contributions $ 55.5 $ 66.6 $ 65.3 *Not applicable (1) To determine individually significant plans, we evaluated several factors, including our total contributions to the plan, our significance to the plan in terms of participating employees and contributions, and the funded status of the plan. (2) The “EIN/PN” column provides the Employer Identification Number and the three-digit plan number assigned to the plan by the IRS. (3) The Pension Protection Act Zone Status columns provide the two most recently available Pension Protection Act zone statuses from each plan. The zone status is based on information provided to us and other participating employers and is certified by each plan’s actuary. Among other factors, plans in the red zone are generally less than 65% funded, plans in the yellow zone are less than 80% funded, and plans in the green zone are at least 80% funded. (4) Indicates whether a Financial Improvement Plan (“FIP”) for yellow zone plans or a Rehabilitation Plan (“RP”) for red zone plans is pending or implemented. (5) Indicates whether our contribution in 2020 included an amount as imposed by a plan in the red zone in addition to the contribution rate specified in the applicable collective bargaining agreement. Multiemployer Pension Plans for which ABM is a Significant Contributor Pension Fund Contributions to the plan exceeded more than 5% of total contributions per most currently available Forms 5500 Arizona Sheet Metal Pension Trust Fund* 6/30/2019 and 6/30/2018 Building Service 32BJ Pension Fund 6/30/2019, 6/30/2018, and 6/30/2017 Building Service Pension Plan* 4/30/2019, 4/30/2018, and 4/30/2017 Contract Cleaners Service Employees’ Pension Plan* 12/31/19, 12/31/2018, and 12/31/2017 Firemen & Oilers Pension Plan of SEIU Local 1* 7/31/2019, 7/31/2018, and 7/31/2017 Massachusetts Service Employees Pension Plan* 12/31/2019, 12/31/2018, and 12/31/2017 SEIU Local 1 & Participating Employers Pension Trust 9/30/2019, 9/30/2018, and 9/30/2017 S.E.I.U. National Industry Pension Fund 12/31/2019, 12/31/2018, and 12/31/2017 Service Employees International Union Local 1 Cleveland Pension Plan* 12/31/2019, 12/31/2018, and 12/31/2017 Service Employees International Union Local 32BJ, District 36 Building Operators Pension Trust Fund* 12/31/2019, 12/31/2018, and 12/31/2017 Teamsters Local 617 Pension Fund* 2/29/2020, 2/28/2019, and 2/28/2018 Teamsters Local Union No. 727 Pension Plan* 2/29/2020, 2/28/2019, and 2/28/2018 * These plans are not separately listed in our multiemployer table as they represent an insignificant portion of our total multiemployer pension plan contributions.

Preferred and Common Stock (Tab

Preferred and Common Stock (Tables)	12 Months Ended
	Oct. 31, 2020
Stockholders' Equity Note [Abstract]
Schedule of Share Repurchase Activity	Year Ended (in millions, except per share amounts) October 31, 2020 Total number of shares purchased 0.2 Average price paid per share $ 36.16 Total cash paid for share repurchases $ 5.1

Share-Based Compensation Plans

Share-Based Compensation Plans (Tables)	12 Months Ended
	Oct. 31, 2020
Share-based Payment Arrangement [Abstract]
Schedule of Compensation Expense by Type of Award and Related Income Tax Benefit	Compensation Expense by Type of Award and Related Income Tax Benefit Years Ended October 31, (in millions) 2020 2019 2018 RSUs $ 11.5 $ 9.5 $ 9.3 Performance shares 8.8 8.0 7.7 Share-based compensation expense before income taxes 20.3 17.5 17.0 Income tax benefit (5.7) (4.9) (5.1) Share-based compensation expense, net of taxes $ 14.6 $ 12.5 $ 11.8
Schedule of RSU Activity	RSU Activity Number of Weighted-Average Outstanding at October 31, 2019 0.7 $ 36.92 Granted 0.7 36.11 Vested (including 0.1 shares withheld for income taxes) (0.2) 37.24 Forfeited (0.1) 37.63 Outstanding at October 31, 2020 1.1 $ 36.32
Schedule of Performance Share Activity	Performance Share Activity Number of Shares Weighted-Average Outstanding at October 31, 2019 0.8 $ 38.06 Granted 0.4 35.92 Vested (including 0.1 shares withheld for income taxes) (0.2) 37.72 Performance adjustments (0.1) 36.85 Forfeited (0.1) 36.58 Outstanding at October 31, 2020 0.8 $ 37.35
Schedule of Monte Carlo Assumptions	Monte Carlo Assumptions 2020 2019 2018 Expected life (1) 2.81 years 2.81 years 2.81 years Expected stock price volatility (2) 28.7 % 27.7 % 21.6 % Risk-free interest rate (3) 1.5 % 2.5 % 2.0 % Stock price (4) $ 37.99 $ 34.92 $ 39.02 (1) The expected life represents the remaining performance period of the awards. (2) The expected volatility for each grant is determined based on the historical volatility of our common stock over a period equal to the remaining term of the performance period from the date of grant for all awards. (3) The risk-free interest rate is based on the continuous compounded yield on U.S. Treasury Constant Maturity Rates with varying remaining terms; the yield is determined over a time period commensurate with the performance period from the grant date. (4) The stock price is the closing price of our common stock on the valuation date.
Schedule of Employee Stock Purchase Plan	Employee Stock Purchase Plan Years Ended October 31, (in millions, except per share amounts) 2020 2019 2018 Weighted-average fair value of granted purchase rights per share $ 1.75 $ 1.77 $ 1.70 Common stock issued 0.1 0.1 0.1 Fair value of common stock issued per share $ 33.18 $ 33.60 $ 32.34 Aggregate purchases $ 3.5 $ 4.1 $ 4.7

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Oct. 31, 2020
Income Tax Disclosure [Abstract]
Schedule of Geographic Sources of Income From Continuing Operations Before Income Taxes	Geographic Sources of Income from Continuing Operations Before Income Taxes Years Ended October 31, (in millions) 2020 2019 2018 United States $ 45.2 $ 137.1 $ 94.8 Foreign 8.1 23.1 (7.1) Income from continuing operations before income taxes $ 53.3 $ 160.2 $ 87.7
Schedule of Components of Income Tax (Provision) Benefit	Components of Income Tax (Provision) Benefit Years Ended October 31, (in millions) 2020 2019 2018 Current: Federal $ (59.3) $ (6.4) $ (4.3) State (28.6) (10.7) (7.3) Foreign (1.7) (5.9) (3.9) Deferred: Federal 23.2 (8.5) 21.8 State 12.5 (1.6) 0.2 Foreign 0.9 0.4 1.7 Income tax (provision) benefit $ (53.1) $ (32.7) $ 8.2
Reconciliation of U.S. Statutory Tax Rate to Annual Effective Tax Rate	Reconciliation of the U.S. Statutory Tax Rate to Annual Effective Tax Rate Years Ended October 31, 2020 2019 2018 U.S. statutory rate 21.0 % 21.0 % 23.3 % State and local income taxes, net of federal tax benefit (0.6) 5.9 6.9 Federal and state tax credits (4.7) (3.9) (7.8) Impact of foreign operations 1.3 (1.0) 1.3 Changes in uncertain tax positions (2.0) (0.8) (6.7) Incremental tax benefit from share-based compensation awards (1.6) (0.7) (3.9) Energy efficiency incentives (3.8) — (3.2) Impact from goodwill impairment 81.7 — 4.4 Transition tax on foreign earnings — (1.1) 5.1 Remeasurement of U.S. deferred taxes — (0.3) (31.5) Nondeductible expenses 4.4 2.1 2.4 Other, net 3.9 (0.8) 0.3 Effective tax rate 99.6 % 20.4 % (9.4) %
Schedule of Components of Deferred Tax Assets and Liabilities	Components of Deferred Tax Assets and Liabilities As of October 31, (in millions) 2020 2019 Deferred tax assets attributable to: Self-insurance claims (net of recoverables) $ 74.7 $ 83.6 Deferred and other compensation 28.6 25.6 Accounts receivable allowances 8.8 5.6 Settlement liabilities 5.0 3.1 Other accruals 1.5 1.8 Other comprehensive income 2.7 0.5 State taxes 1.4 0.4 State net operating loss carryforwards 5.9 11.2 Tax credits 3.7 6.3 Unrecognized tax benefits 3.2 3.0 Deferred payroll taxes 26.9 — Operating lease liabilities 38.2 — Gross deferred tax assets 200.6 141.2 Valuation allowance (4.1) (8.4) Total deferred tax assets 196.5 132.8 Deferred tax liabilities attributable to: Property, plant and equipment (1.2) (4.8) Goodwill and other acquired intangibles (159.4) (170.6) Right-of-use assets (38.2) — Other (8.5) (5.2) Total deferred tax liabilities (207.3) (180.6) Net deferred tax liabilities $ (10.8) $ (47.7)
Schedule of Changes to the Deferred Tax Asset Valuation Allowance	Changes to the Valuation Allowance Years Ended October 31, (in millions) 2020 2019 2018 Valuation allowance at beginning of year $ 8.4 $ 12.0 $ 7.7 GCA acquisition — — 2.4 Other, net (4.3) (3.6) 1.8 Valuation allowance at end of year $ 4.1 $ 8.4 $ 12.0
Reconciliation of Total Unrecognized Tax Benefits	Reconciliation of Total Unrecognized Tax Benefits Years Ended October 31, (in millions) 2020 2019 2018 Balance at beginning of year $ 35.3 $ 35.8 $ 53.4 Additions for tax positions related to the current year 2.1 — 0.2 Additions for tax positions related to prior years 1.6 3.6 — Reductions for tax positions related to prior years — — (9.0) Reductions for lapse of statute of limitations (3.0) (3.9) (8.7) Settlements (0.5) (0.3) (0.1) Balance at end of year $ 35.5 $ 35.3 $ 35.8

Segment and Geographic Inform_2

Segment and Geographic Information (Tables)	12 Months Ended
	Oct. 31, 2020
Segment Reporting [Abstract]
Schedule of Financial Information by Reportable Segment	Financial Information by Reportable Segment Years Ended October 31, (in millions) 2020 2019 2018 Revenues Business & Industry $ 3,157.8 $ 3,251.4 $ 3,268.4 Technology & Manufacturing 956.0 917.0 925.4 Education 808.8 847.4 856.7 Aviation 680.9 1,017.3 1,038.7 Technical Solutions 506.6 593.2 500.1 Elimination of inter-segment revenues (122.4) (127.7) (147.1) $ 5,987.6 $ 6,498.6 $ 6,442.2 Operating profit (loss) Business & Industry $ 253.7 $ 182.3 $ 157.9 Technology & Manufacturing 84.4 72.5 67.4 Education (1) (41.1) 39.0 44.1 Aviation (2) (59.6) 21.1 23.2 Technical Solutions (3) 9.5 55.4 21.8 Government Services (0.1) (0.1) (0.8) Corporate (146.9) (159.0) (168.8) Adjustment for income from unconsolidated affiliates, included in Aviation (2.2) (3.0) (3.2) Adjustment for tax deductions for energy efficient government (2.1) 0.1 (2.8) 95.7 208.3 138.6 Income from unconsolidated affiliates 2.2 3.0 3.2 Interest expense (44.6) (51.1) (54.1) Income from continuing operations before income taxes $ 53.3 $ 160.2 $ 87.7 Depreciation and amortization Business & Industry $ 18.9 $ 21.3 $ 23.6 Technology & Manufacturing 12.5 14.3 15.6 Education 33.8 37.3 37.5 Aviation 10.6 11.9 13.1 Technical Solutions 7.2 8.6 10.2 Corporate 13.5 13.9 12.4 $ 96.4 $ 107.4 $ 112.5 (1) Reflects impairment charges totaling $99.3 million on goodwill during the year ended October 31, 2020. (2) Reflects impairment charges totaling $61.1 million on goodwill and intangible assets during the year ended October 31, 2020. (3) Reflects impairment charges totaling $12.4 million on goodwill and intangible assets during the year ended October 31, 2020.
Schedule of Geographic Information Based on the Country in Which the Sale Originated	Geographic Information Based on the Country in Which the Sale Originated (1) Years Ended October 31, (in millions) 2020 2019 2018 Revenues United States $ 5,625.1 $ 6,025.2 $ 5,997.4 All other countries 362.5 473.3 444.8 $ 5,987.6 $ 6,498.6 $ 6,442.2 (1) Substantially all of our long-lived assets are related to United States operations.

Selected Quarterly Financial _2

Selected Quarterly Financial Data (Unaudited) (Tables)	12 Months Ended
	Oct. 31, 2020
Quarterly Financial Information Disclosure [Abstract]
Schedule of Selected Quarterly Financial Data	Fiscal Quarter (in millions, except per share amounts) First Second Third Fourth Year Ended October 31, 2020 Revenues $ 1,612.9 $ 1,496.0 $ 1,394.1 $ 1,484.6 Gross profit 179.2 189.9 219.2 242.4 Income (loss) from continuing operations 27.9 (136.8) 56.0 53.1 Income from discontinued operations, net of taxes 0.1 — — — Net income (loss) $ 28.0 $ (136.8) (1) $ 56.0 $ 53.1 Net income (loss) per common share — Basic Income (loss) from continuing operations $ 0.42 $ (2.05) $ 0.84 $ 0.79 Income from discontinued operations — — — — Net income (loss) $ 0.42 $ (2.05) $ 0.84 $ 0.79 Net income (loss) per common share — Diluted Income (loss) from continuing operations $ 0.41 $ (2.05) $ 0.83 $ 0.78 Income from discontinued operations — — — — Net income (loss) $ 0.42 $ (2.05) (1) $ 0.83 $ 0.78 Year ended October 31, 2019 Revenues $ 1,607.9 $ 1,594.7 $ 1,647.9 $ 1,648.0 Gross profit 162.0 180.5 193.9 194.7 Income from continuing operations 13.0 29.9 36.5 48.1 (Loss) income from discontinued operations, net of taxes (0.1) (0.2) 0.2 (0.1) Net income $ 13.0 $ 29.7 $ 36.8 $ 47.9 Net income per common share — Basic Income from continuing operations $ 0.20 $ 0.45 $ 0.55 $ 0.72 Income from discontinued operations — — — — Net income $ 0.20 $ 0.45 $ 0.55 $ 0.72 Net income per common share — Diluted Income from continuing operations $ 0.20 $ 0.45 $ 0.55 $ 0.71 Income from discontinued operations — — — — Net income $ 0.19 $ 0.45 $ 0.55 $ 0.71 (1) Includes goodwill and asset impairment charges of $172.8 million, $170.6 million after tax, or $2.54 per diluted share.

The Company and Nature of Ope_2

The Company and Nature of Operations - Narrative (Details)	12 Months Ended
	Oct. 31, 2020segmentindustry_group
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of industry groups | industry_group	4
Number of technical solution segments | segment	1

Basis of Presentation and Sig_4

Basis of Presentation and Significant Accounting Policies - Narrative (Details)	3 Months Ended	12 Months Ended
	Jan. 31, 2020USD ($)	Oct. 31, 2020USD ($)	Oct. 31, 2019USD ($)	Oct. 31, 2018USD ($)
Basis of Presentation [Line Items]
Accrued compensation		$ 187,600,000	$ 189,300,000
Social security tax, employer, deferral, CARES Act		$ 101,000,000
Ownership percentages		33.00%
Investments in unconsolidated affiliates		$ 11,000,000	8,900,000	$ 11,300,000
Proceeds from redemption of auction rate security		5,000,000	0	2,900,000
Auction rate securities		0
Advertising expense		$ 1,800,000	$ 1,700,000	$ 2,300,000
Auction rate securities
Basis of Presentation [Line Items]
Proceeds from redemption of auction rate security	$ 5,000,000
Pandemic
Basis of Presentation [Line Items]
Compensation related costs, percent of health insurance premiums paid by employer, COVID-19		1
Accrued compensation		$ 0
Minimum
Basis of Presentation [Line Items]
Ownership percentages		20.00%
Lease term		1 year
Maximum
Basis of Presentation [Line Items]
Ownership percentages		50.00%
Lease term		30 years

Basis of Presentation and Sig_5

Basis of Presentation and Significant Accounting Policies - Estimated Useful Lives of Property, Plant and Equipment (Details)	12 Months Ended
	Oct. 31, 2020
Computer equipment and software | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Computer equipment and software | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Machinery and other equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	3 years
Machinery and other equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	5 years
Transportation equipment | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	1 year 6 months
Transportation equipment | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	10 years
Buildings | Minimum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	10 years
Buildings | Maximum
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	40 years
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, estimated useful lives	5 years

Basis of Presentation and Sig_6

Basis of Presentation and Significant Accounting Policies - Management Reimbursement Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Segment Reporting Information [Line Items]
Parking facility management fee revenue	$ 1,484.6	$ 1,394.1	$ 1,496	$ 1,612.9	$ 1,648	$ 1,647.9	$ 1,594.7	$ 1,607.9	$ 5,987.6	$ 6,498.6	$ 6,442.2
Management Reimbursement Revenue
Segment Reporting Information [Line Items]
Parking facility management fee revenue									295.6	378.7	376.4
Management Reimbursement Revenue | Business & Industry
Segment Reporting Information [Line Items]
Parking facility management fee revenue									221.4	283.1	276.6
Management Reimbursement Revenue | Aviation
Segment Reporting Information [Line Items]
Parking facility management fee revenue									$ 74.3	$ 95.5	$ 99.9

Basis of Presentation and Sig_7

Basis of Presentation and Significant Accounting Policies - Impact of ROU Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2020	Nov. 01, 2019	Oct. 31, 2019
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets	$ 143.1	$ 167.5
Current portion of lease liabilities	35	36.3
Other accrued liabilities	167.3	155.2	$ 158.2
Long-term lease liabilities	131.4	154.2
Other noncurrent liabilities	$ 168.1	58.8	$ 78.8
Accounting Standards Update 2016-02
New Accounting Pronouncements or Change in Accounting Principle [Line Items]
Right-of-use assets		167.5
Current portion of lease liabilities		36.3
Other accrued liabilities		(3)
Long-term lease liabilities		154.2
Other noncurrent liabilities		$ (20)

Revenues - Disaggregation of Re

Revenues - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Revenue from External Customer [Line Items]
Revenues	$ 1,484.6	$ 1,394.1	$ 1,496	$ 1,612.9	$ 1,648	$ 1,647.9	$ 1,594.7	$ 1,607.9	$ 5,987.6	$ 6,498.6	$ 6,442.2
Operating Segments
Revenue from External Customer [Line Items]
Revenues									6,110	6,626.3
Operating Segments | Business & Industry
Revenue from External Customer [Line Items]
Revenues									3,157.8	3,251.4	3,268.4
Operating Segments | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									956	917	925.4
Operating Segments | Education
Revenue from External Customer [Line Items]
Revenues									808.8	847.4	856.7
Operating Segments | Aviation
Revenue from External Customer [Line Items]
Revenues									680.9	1,017.3	1,038.7
Operating Segments | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									506.6	593.2	$ 500.1
Operating Segments | Janitorial
Revenue from External Customer [Line Items]
Revenues									4,029	3,937.9
Operating Segments | Janitorial | Business & Industry
Revenue from External Customer [Line Items]
Revenues									2,420.4	2,316.1
Operating Segments | Janitorial | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									770.9	739.7
Operating Segments | Janitorial | Education
Revenue from External Customer [Line Items]
Revenues									716.5	756.3
Operating Segments | Janitorial | Aviation
Revenue from External Customer [Line Items]
Revenues									121.2	125.8
Operating Segments | Janitorial | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Parking
Revenue from External Customer [Line Items]
Revenues									654	875.8
Operating Segments | Parking | Business & Industry
Revenue from External Customer [Line Items]
Revenues									362.8	511.5
Operating Segments | Parking | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									33.5	25.9
Operating Segments | Parking | Education
Revenue from External Customer [Line Items]
Revenues									1.8	3.1
Operating Segments | Parking | Aviation
Revenue from External Customer [Line Items]
Revenues									255.9	335.3
Operating Segments | Parking | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Facility Services
Revenue from External Customer [Line Items]
Revenues									647.9	734.6
Operating Segments | Facility Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues									374.1	423.1
Operating Segments | Facility Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									151.6	151.4
Operating Segments | Facility Services | Education
Revenue from External Customer [Line Items]
Revenues									90.5	88
Operating Segments | Facility Services | Aviation
Revenue from External Customer [Line Items]
Revenues									31.6	72.1
Operating Segments | Facility Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Building & Energy Solutions
Revenue from External Customer [Line Items]
Revenues									506.6	593.2
Operating Segments | Building & Energy Solutions | Business & Industry
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Building & Energy Solutions | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Building & Energy Solutions | Education
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Building & Energy Solutions | Aviation
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Building & Energy Solutions | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									506.6	593.2
Operating Segments | Airline Services
Revenue from External Customer [Line Items]
Revenues									272.6	484.8
Operating Segments | Airline Services | Business & Industry
Revenue from External Customer [Line Items]
Revenues									0.4	0.6
Operating Segments | Airline Services | Technology & Manufacturing
Revenue from External Customer [Line Items]
Revenues									0	0.1
Operating Segments | Airline Services | Education
Revenue from External Customer [Line Items]
Revenues									0	0
Operating Segments | Airline Services | Aviation
Revenue from External Customer [Line Items]
Revenues									272.2	484.1
Operating Segments | Airline Services | Technical Solutions
Revenue from External Customer [Line Items]
Revenues									0	0
Intersegment Eliminations
Revenue from External Customer [Line Items]
Revenues									$ (122.4)	$ (127.7)

Revenues - Remaining Performanc

Revenues - Remaining Performance Obligations Narrative (Details) $ in Millions	Oct. 31, 2020USD ($)
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2020-11-01
Revenue from Contract with Customer [Abstract]
Revenue, remaining performance obligation, amount	$ 266.3
Revenue, remaining performance obligation, percentage	61.00%
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, remaining performance obligation, period	12 months

Revenues - Contract with Custom

Revenues - Contract with Customer, Asset and Liability (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Revenue from Contract with Customer [Abstract]
Billed trade receivables	$ 835,800,000	$ 978,700,000
Unbilled trade receivables	53,900,000	56,900,000
Costs incurred in excess of amounts billed	52,200,000	72,600,000
Capitalized commissions	25,200,000	$ 21,800,000
Capitalized contract price	16,400,000
Capitalized contract cost, amortization	13,000,000
Capitalized Contract Cost, Impairment Loss	0
Contract with Customer, Liabilities [Roll Forward]
Contract liabilities, balance at beginning of period	38,000,000
Additional contract liabilities	315,500,000
Recognition of deferred revenue	(317,100,000)
Contract liabilities, balance at end of period	$ 36,400,000

Leases - Supplemental Balance S

Leases - Supplemental Balance Sheet Information (Details) - USD ($) $ in Millions	Oct. 31, 2020	Nov. 01, 2019
Lease assets
Operating lease, right-of-use asset	$ 143.1	$ 167.5
Finance lease, right-of-use asset	$ 6.1
Finance Lease, Right-of-Use Asset, Statement of Financial Position [Extensible List]	us-gaap:PropertyPlantAndEquipmentNet
Total lease assets	$ 149.2
Current liabilities
Operating leases	35	36.3
Finance leases	$ 2.3
Finance Lease, Liability, Current, Statement of Financial Position [Extensible List]	us-gaap:OtherAccruedLiabilitiesCurrent
Noncurrent liabilities
Operating leases	$ 131.4	$ 154.2
Finance leases	$ 2.8
Finance Lease, Liability, Noncurrent, Statement of Financial Position [Extensible List]	us-gaap:OtherLiabilitiesNoncurrent
Total lease liabilities	$ 171.4
Finance leases, accumulated depreciation	$ (13.6)

Leases - Narrative (Details)

Leases - Narrative (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020USD ($)
Leases [Abstract]
Lease, cost	$ 100.4
Operating lease, cost	96.4
Finance lease, cost	$ 4

Leases - Lease Cost (Details)

Leases - Lease Cost (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020USD ($)
Operating lease costs:
Operating lease, cost	$ 96.4
Finance lease costs:
Operating expenses(4)	3.5
Interest expense(5)	0.5
Total lease costs	100.4
Short-term lease costs	47
Variable lease costs	3.5
Total short-term and variable lease costs	50.5
Operating expenses(1)(2)
Operating lease costs:
Operating lease, cost	67.9
Selling, general and administrative expenses(3)
Operating lease costs:
Operating lease, cost	$ 28.5

Leases - Maturities of Operatin

Leases - Maturities of Operating and Finance Lease Liabilities After Adoption of 842 (Details) $ in Millions	Oct. 31, 2020USD ($)
Operating Lease Liabilities
Fiscal 2021	$ 41.3
Fiscal 2022	34.3
Fiscal 2023	29.2
Fiscal 2024	24.1
Fiscal 2025	18.2
Thereafter	43.3
Total lease payments	190.4
Less: imputed interest	24
Present value of lease liabilities	166.4
Finance Lease Liabilities
Fiscal 2021	3.3
Fiscal 2022	1.7
Fiscal 2023	0.9
Fiscal 2024	0
Fiscal 2025	0
Thereafter	0
Total lease payments	5.9
Less: imputed interest	0.8
Present value of lease liabilities	5.1
Total
Fiscal 2021	44.6
Fiscal 2022	36
Fiscal 2023	30.1
Fiscal 2024	24.1
Fiscal 2025	18.2
Thereafter	43.3
Total lease payments	196.3
Less: imputed interest	24.9
Present value of lease liabilities	$ 171.4

Leases - Weighted Average Remai

Leases - Weighted Average Remaining Lease Term and Discount Rate (Details)	Oct. 31, 2020
Weighted-average remaining lease term (years)
Operating leases	6 years 1 month 6 days
Finance leases	2 years
Weighted-average discount rate
Operating leases	4.14%
Finance leases	4.55%

Leases - Supplemental Cash and

Leases - Supplemental Cash and Non-cash Information (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ 44.8
Operating cash flows from finance leases	0.5
Financing cash flows from finance leases	3.4
Lease assets obtained in exchange for new operating lease liabilities(1)	$ 15.7

Leases - Maturities of Operat_2

Leases - Maturities of Operating and Finance Lease Liabilities Before Adoption of 842 (Details) $ in Millions	Oct. 31, 2019USD ($)
Operating and Other
Fiscal 2020	$ 42.8
Fiscal 2021	35.5
Fiscal 2022	30.3
Fiscal 2023	25.6
Fiscal 2024	20.5
Thereafter	51.8
Operating and other leases total	206.5
Capital
Fiscal 2020	3.1
Fiscal 2021	2.5
Fiscal 2022	1.3
Fiscal 2023	0.6
Fiscal 2024	0
Thereafter	0
Total capital leases	7.5
Total
Fiscal 2020	45.9
Fiscal 2021	38
Fiscal 2022	31.6
Fiscal 2023	26.2
Fiscal 2024	20.5
Thereafter	51.8
Total(2)	214
Sublease rental income	$ 15.8

Restructuring and Related Cos_3

Restructuring and Related Costs - Narrative (Details) $ in Millions	Oct. 31, 2020USD ($)
Restructuring Cost and Reserve [Line Items]
Cumulative charges	$ 108.7
2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Cumulative charges	$ 66.5

Restructuring and Related Cos_4

Restructuring and Related Costs - Restructuring and Related Liabilities (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Restructuring Reserve [Roll Forward]
Balance, beginning	$ 7	$ 8.6	$ 8.4
Costs recognized	7.6	11.2	25.7
Payments	(7.9)	(12.9)	(24.7)
Non-cash items	(5.4)		(0.7)
Balance, ending	1.3	7	8.6
External Support Fees
Restructuring Reserve [Roll Forward]
Balance, beginning	0.5	0	2.5
Costs recognized	1.4	1.5	4
Payments	(1.9)	(1)	(6.5)
Non-cash items	0		0
Balance, ending	0	0.5	0
Employee Severance
Restructuring Reserve [Roll Forward]
Balance, beginning	3	3.8	2.7
Costs recognized	0.3	4.6	11
Payments	(2)	(5.3)	(9.9)
Non-cash items	0		0
Balance, ending	1.3	3	3.8
Other Project Fees
Restructuring Reserve [Roll Forward]
Balance, beginning	0.7	1.8	0.4
Costs recognized	3.2	4.5	8.2
Payments	(3.7)	(5.6)	(6.7)
Non-cash items	(0.2)		0
Balance, ending	0	0.7	1.8
Lease Exit Costs
Restructuring Reserve [Roll Forward]
Balance, beginning	2.7	3.1	2.8
Costs recognized	2.7	0.7	2
Payments	(0.2)	(1.1)	(1.5)
Non-cash items	(5.3)		(0.2)
Balance, ending	0	2.7	3.1
Asset Impairment
Restructuring Reserve [Roll Forward]
Balance, beginning	0	0	0
Costs recognized	0	0	0.6
Payments	0	0	0
Non-cash items	0		(0.6)
Balance, ending	$ 0	$ 0	$ 0

Restructuring and Related Cos_5

Restructuring and Related Costs - Cumulative Restructuring and Related Charges (Details) $ in Millions	Oct. 31, 2020USD ($)
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	$ 108.7
GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	42.2
2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	66.5
External Support Fees
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	34.9
External Support Fees | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	4.9
External Support Fees | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	30
Employee Severance
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	31.3
Employee Severance | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	18.3
Employee Severance | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	13
Other Project Fees
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	26.2
Other Project Fees | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	15.5
Other Project Fees | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	10.7
Lease Exit Costs
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	11.1
Lease Exit Costs | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	3.4
Lease Exit Costs | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	7.7
Asset Impairment
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	5.2
Asset Impairment | GCA Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	0
Asset Impairment | 2020 Vision Restructuring Program
Restructuring Cost and Reserve [Line Items]
Restructuring and related cost, cumulative cost	$ 5.2

Net Income Per Common Share - B

Net Income Per Common Share - Basic and Diluted Net Income Per Common Share Calculations (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Schedule of Earnings Per Share, Basic and Diluted, by Common Class [Line Items]
Income from continuing operations	$ 53.1	$ 56	$ (136.8)	$ 27.9	$ 48.1	$ 36.5	$ 29.9	$ 13	$ 0.2	$ 127.5	$ 95.9
Income (loss) from discontinued operations, net of taxes	0	0	0	0.1	(0.1)	0.2	(0.2)	(0.1)	0.1	(0.1)	1.8
Net income	$ 53.1	$ 56	$ (136.8)	$ 28	$ 47.9	$ 36.8	$ 29.7	$ 13	$ 0.3	$ 127.4	$ 97.8
Weighted-average common and common equivalent shares outstanding—Basic (in shares)									66.9	66.6	66.1
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Weighted-average common and common equivalent shares outstanding—Diluted (in shares)									67.3	66.9	66.4
Net income per common share — Basic
Income from continuing operations (usd per share)	$ 0.79	$ 0.84	$ (2.05)	$ 0.42	$ 0.72	$ 0.55	$ 0.45	$ 0.20	$ 0	$ 1.92	$ 1.45
Income from discontinued operations (usd per share)	0	0	0	0	0	0	0	0	0	0	0.03
Net income (usd per share)	0.79	0.84	(2.05)	0.42	0.72	0.55	0.45	0.20	0	1.91	1.48
Net income per common share — Diluted
Income from continuing operations (usd per share)	0.78	0.83	(2.05)	0.41	0.71	0.55	0.45	0.20	0	1.91	1.45
Income from discontinued operations (usd per share)	0	0	0	0	0	0	0	0	0	0	0.03
Net income (usd per share)	$ 0.78	$ 0.83	$ (2.05)	$ 0.42	$ 0.71	$ 0.55	$ 0.45	$ 0.19	$ 0	$ 1.90	$ 1.47
RSUs
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Effect of dilutive securities (in shares)									0.1	0.2	0.1
Stock options
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Effect of dilutive securities (in shares)									0.1	0.1	0.1
Performance shares
Incremental Weighted Average Shares Attributable to Dilutive Effect [Abstract]
Effect of dilutive securities (in shares)									0.1	0.1	0

Net Income Per Common Share - A

Net Income Per Common Share - Anti-Dilutive Outstanding Stock Awards Issued Under Share-Based Compensation Plans (Details) - shares shares in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Earnings Per Share [Abstract]
Anti-dilutive (in shares)	0.4	0.3	0.4

Fair Value of Financial Instr_3

Fair Value of Financial Instruments - Financial Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details)	3 Months Ended	12 Months Ended
	Jan. 31, 2020USD ($)	Oct. 31, 2020USD ($)Security	Oct. 31, 2019USD ($)Security	Oct. 31, 2018USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from redemption of auction rate security		$ 5,000,000	$ 0	$ 2,900,000
Unrealized gain (loss) on auction rate securities		$ 0
Auction rate securities
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in auction rate securities			$ 5,000,000
Number of auction rate securities | Security		0	1
Investments in auction rate securities, principal amount			$ 5,000,000
Proceeds from redemption of auction rate security	$ 5,000,000
Fair Value Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents		$ 394,200,000	58,500,000
Insurance deposits		700,000	800,000
Assets held in funded deferred compensation plan		2,600,000	2,500,000
Fair Value Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Credit facility		725,300,000	808,400,000
Interest rate swaps liabilities		15,500,000	14,600,000
Fair Value Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Investments in auction rate securities		0	5,000,000
Investments in auction rate securities, principal amount		$ 0	$ 5,000,000

Property, Plant and Equipment -

Property, Plant and Equipment - Schedule of Property, Plant and Equipment (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 375	$ 349.8
Less: Accumulated depreciation	241.3	199.5
Total	133.7	150.3
Depreciation expense	48	48.9	$ 46.5
Machinery and other equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	137	118.8
Computer equipment and software
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	101.2	91.7
Transportation equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	57.7	57.4
Leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	57.1	59.5
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	13.7	13.1
Buildings
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	7.6	8.2
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 0.7	$ 1

Property, Plant and Equipment_2

Property, Plant and Equipment - Capital Leases Included in Property, Plant and Equipment (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	$ 19.7	$ 20.6
Less: Accumulated depreciation	13.6	10.7
Total	6.1	9.9
Transportation equipment
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	19.4	20
Furniture and fixtures
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	0.2	0.2
Machinery and other equipment
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	0	0.3
Computer equipment and software
Property, Plant and Equipment [Line Items]
Capital leased assets, gross	$ 0	$ 0.1

Goodwill and Other Intangible_3

Goodwill and Other Intangible Assets - Changes in Carrying Amounts of Goodwill by Segment (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Goodwill [Roll Forward]
Beginning balance	$ 1,835.4	$ 1,834.8
Reallocation		0
Foreign currency translation	(0.2)	0.6
Impairment loss	(163.8)
Ending balance	1,671.4	1,835.4
Business & Industry
Goodwill [Roll Forward]
Beginning balance	573.9	527.9
Reallocation		45.7
Foreign currency translation	0.1	0.3
Impairment loss	0
Ending balance	574	573.9
Technology & Manufacturing
Goodwill [Roll Forward]
Beginning balance	407.2	407.2
Reallocation		0
Foreign currency translation	0	0
Impairment loss	0
Ending balance	407.2	407.2
Education
Goodwill [Roll Forward]
Beginning balance	558.6	557.4
Reallocation		1.2
Foreign currency translation	0	0
Impairment loss	(99.3)
Ending balance	459.3	558.6
Aviation
Goodwill [Roll Forward]
Beginning balance	125	124.9
Reallocation		0
Foreign currency translation	0	0.1
Impairment loss	(55.5)
Ending balance	69.5	125
Technical Solutions
Goodwill [Roll Forward]
Beginning balance	170.7	158.7
Reallocation		11.8
Foreign currency translation	(0.3)	0.3
Impairment loss	(9)
Ending balance	161.5	170.7
Healthcare
Goodwill [Roll Forward]
Beginning balance	0	58.7
Reallocation		(58.7)
Foreign currency translation	0	0
Impairment loss
Ending balance	$ 0	$ 0

Goodwill and Other Intangible_4

Goodwill and Other Intangible Assets - Narrative (Details)	Oct. 31, 2020segment
Goodwill and Intangible Assets Disclosure [Abstract]
Number of reporting units evaluated for impairment	3

Goodwill and Other Intangible_5

Goodwill and Other Intangible Assets - Discount Rates (Details) - Discount Rates	Oct. 31, 2020
Valuation, Market Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Reporting unit, measurement input	0.150
Education | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Reporting unit, measurement input	0.100
Aviation | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Reporting unit, measurement input	0.105
Technical Solutions | Valuation, Income Approach
Fair Value Measurement Inputs and Valuation Techniques [Line Items]
Reporting unit, measurement input	0.110

Goodwill and Other Intangible_6

Goodwill and Other Intangible Assets - Other Intangible Assets (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 583,500,000	$ 606,200,000
Accumulated Amortization	(343,800,000)	(309,000,000)
Total	239,700,000	297,200,000
Net impairment charge	$ 9,000,000	$ 0
Intangible assets weighted average life	11 years	11 years
Aviation
Acquired Indefinite-lived Intangible Assets [Line Items]
Net impairment charge	$ 5,600,000
Reduction in carrying amount	(13,800,000)
Amortization of intangible assets	8,200,000
Technical Solutions
Acquired Indefinite-lived Intangible Assets [Line Items]
Net impairment charge	3,400,000
Reduction in carrying amount	(8,700,000)
Amortization of intangible assets	5,300,000
Customer contracts and relationships
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	573,100,000	$ 595,900,000
Accumulated Amortization	(333,600,000)	(298,900,000)
Total	239,600,000	297,000,000
Trademarks and trade names
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	9,800,000	9,800,000
Accumulated Amortization	(9,800,000)	(9,800,000)
Total	0	100,000
Contract rights and other
Acquired Indefinite-lived Intangible Assets [Line Items]
Gross Carrying Amount	500,000	500,000
Accumulated Amortization	(400,000)	(400,000)
Total	$ 100,000	$ 100,000

Goodwill and Other Intangible_7

Goodwill and Other Intangible Assets - Estimated Annual Amortization Expense (Details) $ in Millions	Oct. 31, 2020USD ($)
Goodwill and Intangible Assets Disclosure [Abstract]
Estimated amortization expense 2021	$ 42.1
Estimated amortization expense 2022	36.8
Estimated amortization expense 2023	32.2
Estimated amortization expense 2024	28
Estimated amortization expense 2025	$ 23.9

Insurance - Narrative (Details)

Insurance - Narrative (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Schedule of Other Liabilities [Line Items]
Insurance policy coverage, general and automobile liability losses	$ 200,000,000
Insurance policy coverage, property damage	75,000,000
Decrease in reserves for insurance claims	(36,600,000)
Change in case reserves plus IBNR Claims — prior years	(30,200,000)	$ (3,400,000)	$ 10,200,000
Minimum
Schedule of Other Liabilities [Line Items]
Self insurance retention amount per-claim	1,000,000
Primary policy limit	1,000,000
Maximum
Schedule of Other Liabilities [Line Items]
Self insurance retention amount per-claim	1,500,000
Primary policy limit	5,000,000
Self insurance retention amount per participant per year	$ 500,000

Insurance - Insurance Related B

Insurance - Insurance Related Balances and Activity (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Liability for Claims and Claims Adjustment Expense [Line Items]
Insurance recoverables	$ 70.1	$ 64.5	$ 73.7
Insurance claim reserves, excluding medical and dental
Liability for Claims and Claims Adjustment Expense [Line Items]
Insurance claims reserves	504.9	507.8
Medical and dental claim reserves
Liability for Claims and Claims Adjustment Expense [Line Items]
Insurance claims reserves	$ 16.6	$ 7.2

Insurance - Casualty Program In

Insurance - Casualty Program Insurance Reserves Rollforward (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Liability for Unpaid Claims and Claims Adjustment Expense [Roll Forward]
Net balance at beginning of year	$ 443.3	$ 427.7	$ 412.5
Change in case reserves plus IBNR Claims — current year	128.5	137.9	131.4
Change in case reserves plus IBNR Claims — prior years	(30.2)	(3.4)	10.2
Claims paid	(106.8)	(119.1)	(126.5)
GCA acquisition	0.2	0	0.1
Net balance at end of year	434.8	443.3	427.7
Recoverables	70.1	64.5	73.7
Gross balance at end of year	504.9	507.8	501.4
Provision related to discontinued operations	$ 0.5	$ 1	$ 3

Insurance - Instruments Used to

Insurance - Instruments Used to Collateralize Insurance Obligations (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 226.9	$ 232.6
Standby letters of credit
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	143.6	141
Surety bonds
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	82.6	90.8
Restricted insurance deposits
Letters Of Credit [Line Items]
Instruments used to collateralize insurance obligations	$ 0.7	$ 0.8

Credit Facility - Narrative (De

Credit Facility - Narrative (Details)	May 28, 2020USD ($)	Sep. 01, 2017USD ($)	Mar. 31, 2020USD ($)	Oct. 31, 2020	May 27, 2020	Sep. 01, 2018USD ($)	Aug. 31, 2017USD ($)
Credit Facility
Debt Instrument [Line Items]
Line of credit facility, term		5 years
Fixed charge coverage ratio					1.25
Debt instrument, covenant, liquidity required, minimum	$ 250,000,000
Debt instrument, covenant, cash and cash equivalents, maximum	250,000,000
Weighted average interest rate				2.45%
Deferred financing costs	$ 4,600,000	$ 18,700,000
Credit Facility | Covenant Period, Quarter Ended October 2020
Debt Instrument [Line Items]
Leverage ratio					6.50
Credit Facility | Covenant Period, Quarter Ending October 2022
Debt Instrument [Line Items]
Leverage ratio					4
Line of Credit | Credit Facility
Debt Instrument [Line Items]
Deferred financing costs		5,200,000
Term Loan | Credit Facility
Debt Instrument [Line Items]
Debt instrument, face amount		800,000,000
Deferred financing costs		$ 13,400,000
Revolving Credit Facility | Minimum
Debt Instrument [Line Items]
Percentage of commitment fee on the unused portion of the Facility	0.20%
Revolving Credit Facility | Maximum
Debt Instrument [Line Items]
Percentage of commitment fee on the unused portion of the Facility	0.45%
Revolving Credit Facility | Credit Facility | Minimum
Debt Instrument [Line Items]
Percentage of commitment fee on the unused portion of the Facility		0.20%
Revolving Credit Facility | Credit Facility | Maximum
Debt Instrument [Line Items]
Percentage of commitment fee on the unused portion of the Facility		0.35%
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Proceeds from lines of credit			$ 300,000,000
Revolving Credit Facility | Line of Credit | Prior Credit Facility
Debt Instrument [Line Items]
Line of credit, borrowing capacity							$ 800,000,000
Revolving Credit Facility | Line of Credit | Credit Facility
Debt Instrument [Line Items]
Line of credit, borrowing capacity		$ 900,000,000
Borrowing capacity after initial year of term						$ 800,000,000
Standby letters of credit | Credit Facility
Debt Instrument [Line Items]
Line of credit, borrowing capacity		300,000,000
Swing Line Loan | Credit Facility
Debt Instrument [Line Items]
Line of credit, borrowing capacity		$ 75,000,000
Eurodollar | Credit Facility | Minimum
Debt Instrument [Line Items]
Variable interest rate	1.00%	1.00%
Eurodollar | Credit Facility | Maximum
Debt Instrument [Line Items]
Variable interest rate	2.75%	2.25%
Base Rate | Credit Facility | Minimum
Debt Instrument [Line Items]
Variable interest rate	0.00%	0.00%
Base Rate | Credit Facility | Maximum
Debt Instrument [Line Items]
Variable interest rate	1.75%	1.25%

Credit Facility - Credit Facili

Credit Facility - Credit Facility Information (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Current portion of long-term debt
Gross term loan	$ 120	$ 60
Unamortized deferred financing costs	(3.3)	(2.8)
Current portion of term loan	116.7	57.2
Long-term debt
Gross term loan	560	680
Unamortized deferred financing costs	(2.3)	(4.1)
Total noncurrent portion of term loan	557.7	675.9
Line of credit	45.3	68.4
Long-term debt	603	$ 744.2
Standby letters of credit	153.1
Borrowing capacity	$ 596.6

Credit Facility - Term Loan Mat

Credit Facility - Term Loan Maturities (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020USD ($)
Debt Instrument [Line Items]
Debt instrument, periodic payment, principal	$ 60
Term Loan
Term Loan Maturities
Debt maturities, 2021	120
Debt maturities, 2022	$ 560

Credit Facility - Interest Rate

Credit Facility - Interest Rate Swaps (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018	Nov. 01, 2018
Line of Credit Facility [Line Items]
Interest expense	$ 44,600,000	$ 51,100,000	$ 54,100,000
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, net	(4,000,000)
Interest rate cash flow hedge gain (loss) to be reclassified during next 12 months, tax	(1,400,000)
Interest Rate Swap, Maturity 4/30/2021
Line of Credit Facility [Line Items]
Notional Amount				$ 90,000,000
Derivative, fixed interest rate (percent)				2.83%
Interest Rate Swap, Maturity 10/31/2021
Line of Credit Facility [Line Items]
Notional Amount				$ 90,000,000
Derivative, fixed interest rate (percent)				2.84%
Interest Rate Swap, Maturity 4/30/2022
Line of Credit Facility [Line Items]
Notional Amount				$ 130,000,000
Derivative, fixed interest rate (percent)				2.86%
Interest Rate Swap, Maturity 9/1/2022
Line of Credit Facility [Line Items]
Notional Amount				$ 130,000,000
Derivative, fixed interest rate (percent)				2.84%
Accumulated Gain (Loss), Cash Flow Hedge, Including Noncontrolling Interest
Line of Credit Facility [Line Items]
Net gains from cash flow hedges recorded in accumulated other comprehensive loss, net of tax	(3,300,000)	2,200,000
Tax related to amounts in accumulated other comprehensive loss	(900,000)	1,200,000
Interest expense	(4,900,000)	4,100,000
Interest expense, net of taxes	$ (1,800,000)	$ 1,500,000

Employee Benefit Plans - Define

Employee Benefit Plans - Defined Benefit Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Net obligations	$ 9.6	$ 8.4
Projected benefit obligations	17	16.1
Fair value of assets	7.4	7.8
Expected return on assets	0.4	0.4	$ 0.4
Net periodic benefit cost	0.2	$ 0.6	$ 0.2
Expected future benefit payments	$ 14.4
Equity Securities
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	48.00%
Fixed Income Funds
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	51.00%
Cash and Cash Equivalents
Defined Benefit Plan Disclosure [Line Items]
Target plan asset allocations	1.00%

Employee Benefit Plans - Deferr

Employee Benefit Plans - Deferred Compensation Plans (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Deferred Compensation Plans
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Total liability of deferred compensation	$ 13.6	$ 13.2
Compensation expense	0.2	0.3	$ 0.4
Rabbi Trust
Deferred Compensation Arrangement with Individual, Postretirement Benefits [Line Items]
Fair value deferred compensation plan assets	$ 2.6	$ 2.5

Employee Benefit Plans - Defi_2

Employee Benefit Plans - Defined Contribution Plans (Details) $ in Millions	12 Months Ended
	Oct. 31, 2020USD ($)defined_contribution_plan	Oct. 31, 2019USD ($)	Oct. 31, 2018USD ($)
Retirement Benefits [Abstract]
Number of defined contribution plans | defined_contribution_plan	4
Cost recognized | $	$ 18.2	$ 24.3	$ 21.6

Employee Benefit Plans - Multie

Employee Benefit Plans - Multiemployer Defined Benefit Pension Plans (Details) - Multiemployer Plans, Pension Plans - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Multiemployer Plans [Line Items]
Total Contributions	$ 55.5	$ 66.6	$ 65.3
Minimum
Multiemployer Plans [Line Items]
Green Zone funded percent - Minimum	80.00%	80.00%
Maximum
Multiemployer Plans [Line Items]
Red Zone funded percent - Maximum	65.00%	65.00%
Yellow Zone funded percent - Maximum	80.00%	80.00%
Building Service 32BJ Pension Fund
Multiemployer Plans [Line Items]
Multiemployer EIN	131879376
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Red	Red
Pension Protection Act Zone Status, Date	Jun. 30, 2019	Jun. 30, 2018
FIP/RP Status Pending/Implemented	Implemented
Contributions by ABM, significant	$ 16.8	$ 19.3	19.9
Surcharge Imposed(5)	No
Building Service 32BJ Pension Fund | Minimum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Oct. 15, 2023
Building Service 32BJ Pension Fund | Maximum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Dec. 31, 2023
S.E.I.U. National Industry Pension Fund
Multiemployer Plans [Line Items]
Multiemployer EIN	526148540
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Red	Red
Pension Protection Act Zone Status, Date	Dec. 31, 2019	Dec. 31, 2018
FIP/RP Status Pending/Implemented	Implemented
Contributions by ABM, significant	$ 11.1	$ 10.6	8.7
Surcharge Imposed(5)	Yes
S.E.I.U. National Industry Pension Fund | Minimum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Jun. 30, 2021
S.E.I.U. National Industry Pension Fund | Maximum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Oct. 31, 2023
Central Pension Fund of the IUOE & Participating Employers
Multiemployer Plans [Line Items]
Multiemployer EIN	366052390
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Green	Green
Pension Protection Act Zone Status, Date	Jan. 31, 2020	Jan. 31, 2019
FIP/RP Status Pending/Implemented	NA
Contributions by ABM, significant	$ 7.1	$ 11.7	11
Surcharge Imposed(5)	NA
Central Pension Fund of the IUOE & Participating Employers | Minimum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Apr. 30, 2021
Central Pension Fund of the IUOE & Participating Employers | Maximum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Dec. 31, 2022
SEIU Local 1 & Participating Employers Pension Trust
Multiemployer Plans [Line Items]
Multiemployer EIN	366486542
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Green	Green
Pension Protection Act Zone Status, Date	Sep. 30, 2019	Sep. 30, 2018
FIP/RP Status Pending/Implemented	NA
Contributions by ABM, significant	$ 4.3	$ 5.1	5.8
Surcharge Imposed(5)	NA
Expiration Dates of Collective Bargaining Agreements	Apr. 4, 2021
IUOE Stationary Engineers Local 39 Pension Plan
Multiemployer Plans [Line Items]
Multiemployer EIN	946118939
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Green	Green
Pension Protection Act Zone Status, Date	Dec. 31, 2019	Dec. 31, 2018
FIP/RP Status Pending/Implemented	NA
Contributions by ABM, significant	$ 4.3	$ 4.6	5.2
Surcharge Imposed(5)	NA
IUOE Stationary Engineers Local 39 Pension Plan | Minimum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Nov. 15, 2020
IUOE Stationary Engineers Local 39 Pension Plan | Maximum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Oct. 31, 2024
Western Conference of Teamsters Pension Plan
Multiemployer Plans [Line Items]
Multiemployer EIN	916145047
Multiemployer Plan Number	001
Pension Protection Act Zone Status(3)	Green	Green
Pension Protection Act Zone Status, Date	Dec. 31, 2019	Dec. 31, 2018
FIP/RP Status Pending/Implemented	NA
Contributions by ABM, significant	$ 2.5	$ 3.1	3.1
Surcharge Imposed(5)	NA
Western Conference of Teamsters Pension Plan | Minimum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Jun. 30, 2021
Western Conference of Teamsters Pension Plan | Maximum
Multiemployer Plans [Line Items]
Expiration Dates of Collective Bargaining Agreements	Nov. 30, 2022
All Other Plans
Multiemployer Plans [Line Items]
Contributions by ABM, insignificant	$ 9.5	$ 12.2	$ 11.5

Employee Benefit Plans - Mult_2

Employee Benefit Plans - Multiemployer Plans Additional Information (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Defined Benefit Plan Disclosure [Line Items]
Cost recognized	$ 18.2	$ 24.3	$ 21.6
Multiemployer Plans, Pension Plans | Defined Contribution Plans
Defined Benefit Plan Disclosure [Line Items]
Cost recognized	15.5	9	10.6
Multiemployer Plans, Postretirement Benefit Plans
Defined Benefit Plan Disclosure [Line Items]
Contributions by ABM	$ 264.8	$ 269.8	$ 263.4

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details)	Sep. 20, 2018subclass	Oct. 31, 2020USD ($)	Oct. 31, 2019USD ($)
Loss Contingencies [Line Items]
Letters of credit		$ 153,100,000
Surety bonds		$ 632,900,000
Subsidiary ownership interest percentage		33.00%
Minimum
Loss Contingencies [Line Items]
Subsidiary ownership interest percentage		20.00%
Estimate of reasonably possible loss		$ 0
Maximum
Loss Contingencies [Line Items]
Subsidiary ownership interest percentage		50.00%
Estimate of reasonably possible loss		$ 4,000,000
Bucio
Loss Contingencies [Line Items]
Number of certified subclasses | subclass	4
Energy Savings Contracts
Loss Contingencies [Line Items]
Guarantee obligation		182,800,000	$ 174,800,000
Performance Guarantee | Joint Venture
Loss Contingencies [Line Items]
Total guarantee		30,000,000
Pending Litigation
Loss Contingencies [Line Items]
Loss contingency amount accrued for probable losses		$ 14,700,000

Preferred and Common Stock - Na

Preferred and Common Stock - Narrative (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018	Dec. 18, 2019
Equity, Class of Treasury Stock [Line Items]
Preferred stock, shares authorized (in shares)	500,000	500,000
Preferred stock, shares issued (in shares)	0	0
Total number of shares repurchased (in shares)	200,000	0	0
2019 Share Repurchase Program
Equity, Class of Treasury Stock [Line Items]
Share repurchase program, authorized amount				$ 150,000,000
Share repurchase program, remaining authorized amount	$ 144,900,000

Preferred and Common Stock - Re

Preferred and Common Stock - Repurchase Activity (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Stockholders' Equity Note [Abstract]
Total number of shares repurchased (in shares)	200,000	0	0
Average price paid per share (usd per share)	$ 36.16
Total cash paid for share repurchases	$ 5.1

Share-Based Compensation Plan_2

Share-Based Compensation Plans - Narrative (Details) - USD ($)	12 Months Ended
	Oct. 31, 2020	Mar. 31, 2018	Mar. 31, 2016	May 01, 2006
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Holding period for shares purchased in program	6 months
2006 Equity Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)		13,475,265
Number of shares available for grant (in shares)	2,086,078
2004 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Number of shares authorized (in shares)			4,000,000
Fair value percentage of common stock price				95.00%
Employee contribution percentage				10.00%
Maximum annual employee contribution				$ 25,000
Number of shares unissued (in shares)	599,159

Share-Based Compensation Plan_3

Share-Based Compensation Plans - Compensation Expense by Type of Award and Related Income Tax Benefit (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before income taxes	$ 20.3	$ 17.5	$ 17
Income tax benefit	(5.7)	(4.9)	(5.1)
Share-based compensation expense, net of taxes	14.6	12.5	11.8
RSUs
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before income taxes	11.5	9.5	9.3
Performance shares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense before income taxes	$ 8.8	$ 8	$ 7.7

Share-Based Compensation Plan_4

Share-Based Compensation Plans - RSU Narrative (Details) - RSUs - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Exercisable rate	50.00%
Total unrecognized compensation cost, net of estimated forfeitures	$ 25.2
Weighted-average vesting period	1 year 10 months 24 days
Fair value per share of awards granted (usd per share)	$ 36.11	$ 34.48	$ 37.98
Total fair value of RSUs vested	$ 6.1	$ 10.7	$ 7.4

Share-Based Compensation Plan_5

Share-Based Compensation Plans - RSU Activity (Details) - RSUs - $ / shares shares in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Number of Shares
Beginning balance (in shares)	0.7
Granted (in shares)	0.7
Vested (in shares)	(0.2)
Forfeited (in shares)	(0.1)
Ending balance (in shares)	1.1	0.7
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Weighted Average Grant Date Fair Value [Abstract]
Beginning balance (usd per share)	$ 36.92
Granted (usd per share)	36.11	$ 34.48	$ 37.98
Vested (usd per share)	37.24
Forfeited (usd per share)	37.63
Ending balance (usd per share)	$ 36.32	$ 36.92
Shares withheld for income taxes (in shares)	0.1

Share-Based Compensation Plan_6

Share-Based Compensation Plans - Performance Share Narrative (Details) - Performance shares - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period	3 years
Total unrecognized compensation cost	$ 14.4
Weighted-average vesting period	1 year 10 months 24 days
Service period	3 years
Fair value per share of awards granted (usd per share)	$ 35.92	$ 35.44	$ 38.53
Total fair value of RSUs vested	$ 6.1	$ 6.8	$ 7.3
Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of awards originally granted	0.00%
Maximum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Percentage of awards originally granted	150.00%

Share-Based Compensation Plan_7

Share-Based Compensation Plans - Performance Share Activity (Details) - Performance shares - $ / shares shares in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Number of Shares
Beginning balance (in shares)	0.8
Granted (in shares)	0.4
Vested (in shares)	(0.2)
Performance adjustments (in shares)	(0.1)
Forfeited (in shares)	(0.1)
Ending balance (in shares)	0.8	0.8
Weighted-Average Grant Date Fair Value per Share
Beginning balance (usd per share)	$ 38.06
Granted (usd per share)	35.92	$ 35.44	$ 38.53
Vested (usd per share)	37.72
Performance adjustments (usd per share)	36.85
Forfeited (usd per share)	36.58
Ending balance (usd per share)	$ 37.35	$ 38.06
Shares withheld for income taxes (in shares)	0.1

Share-Based Compensation Plan_8

Share-Based Compensation Plans - Monte Carlo Assumptions (Details) - $ / shares	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Share-based Payment Arrangement [Abstract]
Expected life	2 years 9 months 21 days	2 years 9 months 21 days	2 years 9 months 21 days
Expected stock price volatility	28.70%	27.70%	21.60%
Risk-free interest rate	1.50%	2.50%	2.00%
Stock price (usd per share)	$ 37.99	$ 34.92	$ 39.02

Share-Based Compensation Plan_9

Share-Based Compensation Plans - Employee Stock Purchase Plan (Details) - Employee Stock Purchase Plan - USD ($) $ / shares in Units, shares in Millions, $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average fair value of granted purchase rights per share (usd per share)	$ 1.75	$ 1.77	$ 1.70
Common stock issued (in shares)	0.1	0.1	0.1
Fair value of common stock issued per share (usd per share)	$ 33.18	$ 33.60	$ 32.34
Aggregate purchases	$ 3.5	$ 4.1	$ 4.7

Income Taxes - Components of In

Income Taxes - Components of Income From Continuing Operations Before Income Taxes and Provision for Income Taxes (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Income Tax Disclosure [Abstract]
United States	$ 45.2	$ 137.1	$ 94.8
Foreign	8.1	23.1	(7.1)
Income from continuing operations before income taxes	53.3	160.2	87.7
Current:
Federal	(59.3)	(6.4)	(4.3)
State	(28.6)	(10.7)	(7.3)
Foreign	(1.7)	(5.9)	(3.9)
Deferred:
Federal	23.2	(8.5)	21.8
State	12.5	(1.6)	0.2
Foreign	0.9	0.4	1.7
Income tax (provision) benefit	$ (53.1)	$ (32.7)	$ 8.2

Income Taxes - Reconciliation o

Income Taxes - Reconciliation of U.S. Statutory Tax Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Income Tax Disclosure [Abstract]
U.S. statutory rate	21.00%	21.00%	23.30%
State and local income taxes, net of federal tax benefit	(0.60%)	5.90%	6.90%
Federal and state tax credits	(4.70%)	(3.90%)	(7.80%)
Impact of foreign operations	1.30%	(1.00%)	1.30%
Changes in uncertain tax positions	(2.00%)	(0.80%)	(6.70%)
Incremental tax benefit from share-based compensation awards	(1.60%)	(0.70%)	(3.90%)
Energy efficiency incentives	(3.80%)	0.00%	(3.20%)
Impact from goodwill impairment	81.70%	0.00%	4.40%
Transition tax on foreign earnings	0.00%	(1.10%)	5.10%
Remeasurement of U.S. deferred taxes	0.00%	(0.30%)	(31.50%)
Nondeductible expenses	4.40%	2.10%	2.40%
Other, net	3.90%	(0.80%)	0.30%
Effective tax rate	99.60%	20.40%	(9.40%)

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) $ in Millions	3 Months Ended	12 Months Ended
	Oct. 31, 2019USD ($)	Oct. 31, 2020USD ($)state	Oct. 31, 2019USD ($)	Oct. 31, 2018USD ($)
Income Taxes [Line Items]
U.S. statutory rate		21.00%	21.00%	23.30%
Net discrete tax benefit from remeasurement of deferred taxes at new rate due to Tax Act				$ 29.6
Remeasurement of one-time transition tax on deemed repatriation of indefinitely reinvested earnings			$ 2.7	$ (4.5)
Tax benefit related to lapse of statute of limitations	$ (1.8)		$ (1.3)
Effective tax rate (percent)		99.60%	20.40%	(9.40%)
Income tax provision		$ (53.1)	$ (32.7)	$ 8.2
Nondeductible impairment loss		$ 163.8
Effective tax rate , excluding nondeductible impairment loss (percent)		24.40%
State true-ups		$ 5.7	1.7
Work opportunity tax credit, adjustment		2.3	1.3
Income tax benefit related to deduction for energy efficiency		2.1
Income tax benefit related to change in tax reserves		1.1
Federal true-ups			(1.6)
Income tax benefit related to vesting of share-based compensation awards			(1.1)
Benefit resulting from research and development credits			(0.9)
Tax credits		4.4
Unrecognized tax benefits that would impact effective tax rate	35.3	35.5	35.3	35.8
Maximum decrease in unrecognized tax benefits that is reasonably possible		0.6
Uncertain tax positions, interest and penalties accrued	$ 1.2	1.5	1.2
Unrecognized tax benefits, interest and penalties expense		$ 0.4	$ 0.2
Unrecognized tax benefits, interest and penalties benefit				$ (1)
Number of states in which entity operates | state		50
State and Local Jurisdiction
Income Taxes [Line Items]
Operating loss carryforwards		$ 102.3

Income Taxes - Components of De

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Millions	Oct. 31, 2020	Oct. 31, 2019
Deferred tax assets attributable to:
Self-insurance claims (net of recoverables)	$ 74.7	$ 83.6
Deferred and other compensation	28.6	25.6
Accounts receivable allowances	8.8	5.6
Settlement liabilities	5	3.1
Other accruals	1.5	1.8
Other comprehensive income	2.7	0.5
State taxes	1.4	0.4
State net operating loss carryforwards	5.9	11.2
Tax credits	3.7	6.3
Unrecognized tax benefits	3.2	3
Deferred payroll taxes	26.9	0
Operating lease liabilities	38.2
Gross deferred tax assets	200.6	141.2
Valuation allowance	(4.1)	(8.4)
Total deferred tax assets	196.5	132.8
Deferred tax liabilities attributable to:
Property, plant and equipment	(1.2)	(4.8)
Goodwill and other acquired intangibles	(159.4)	(170.6)
Right-of-use assets	(38.2)
Other	(8.5)	(5.2)
Total deferred tax liabilities	(207.3)	(180.6)
Net deferred tax liabilities	$ (10.8)	$ (47.7)

Income Taxes - Changes to Defer

Income Taxes - Changes to Deferred Tax Asset Valuation Allowance (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Operating Loss Carryforwards, Valuation Allowance Rollforward [Roll Forward]
Valuation allowance at beginning of year	$ 8.4	$ 12	$ 7.7
GCA acquisition	0	0	2.4
Other, net	(4.3)	(3.6)	1.8
Valuation allowance at end of year	$ 4.1	$ 8.4	$ 12

Income Taxes - Reconciliation_2

Income Taxes - Reconciliation of Total Unrecognized Tax Benefits (Details) - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Beginning balance	$ 35.3	$ 35.8	$ 53.4
Additions for tax positions related to the current year	2.1	0	0.2
Additions for tax positions related to prior years	1.6	3.6	0
Reductions for tax positions related to prior years	0	0	(9)
Reductions for lapse of statute of limitations	(3)	(3.9)	(8.7)
Settlements	(0.5)	(0.3)	(0.1)
Ending Balance	$ 35.5	$ 35.3	$ 35.8

Segment and Geographic Inform_3

Segment and Geographic Information - Financial Information by Reportable Segment (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Revenues
Revenues	$ 1,484.6	$ 1,394.1	$ 1,496	$ 1,612.9	$ 1,648	$ 1,647.9	$ 1,594.7	$ 1,607.9	$ 5,987.6	$ 6,498.6	$ 6,442.2
Operating profit (loss)
Operating profit (loss)									95.7	208.3	138.6
Income from unconsolidated affiliates									2.2	3	3.2
Interest expense									(44.6)	(51.1)	(54.1)
Income from continuing operations before income taxes									53.3	160.2	87.7
Depreciation and amortization
Depreciation and amortization									96.4	107.4	112.5
Goodwill, impairment loss									163.8
Impairment loss									172.8	0	26.5
Operating Segments
Revenues
Revenues									6,110	6,626.3
Corporate
Operating profit (loss)
Operating profit (loss)									(146.9)	(159)	(168.8)
Depreciation and amortization
Depreciation and amortization									13.5	13.9	12.4
Segment Reconciling Items
Operating profit (loss)
Adjustment for tax deductions for energy efficient government buildings, included in Technical Solutions									(2.1)	0.1	(2.8)
Income from unconsolidated affiliates									(2.2)	(3)	(3.2)
Business & Industry
Depreciation and amortization
Goodwill, impairment loss									0
Business & Industry | Operating Segments
Revenues
Revenues									3,157.8	3,251.4	3,268.4
Operating profit (loss)
Operating profit (loss)									253.7	182.3	157.9
Depreciation and amortization
Depreciation and amortization									18.9	21.3	23.6
Technology & Manufacturing
Depreciation and amortization
Goodwill, impairment loss									0
Technology & Manufacturing | Operating Segments
Revenues
Revenues									956	917	925.4
Operating profit (loss)
Operating profit (loss)									84.4	72.5	67.4
Depreciation and amortization
Depreciation and amortization									12.5	14.3	15.6
Education
Depreciation and amortization
Goodwill, impairment loss									99.3
Education | Operating Segments
Revenues
Revenues									808.8	847.4	856.7
Operating profit (loss)
Operating profit (loss)									(41.1)	39	44.1
Depreciation and amortization
Depreciation and amortization									33.8	37.3	37.5
Aviation
Depreciation and amortization
Goodwill, impairment loss									55.5
Impairment loss									61.1
Aviation | Operating Segments
Revenues
Revenues									680.9	1,017.3	1,038.7
Operating profit (loss)
Operating profit (loss)									(59.6)	21.1	23.2
Depreciation and amortization
Depreciation and amortization									10.6	11.9	13.1
Technical Solutions
Depreciation and amortization
Goodwill, impairment loss									9
Impairment loss									12.4
Technical Solutions | Operating Segments
Revenues
Revenues									506.6	593.2	500.1
Operating profit (loss)
Operating profit (loss)									9.5	55.4	21.8
Depreciation and amortization
Depreciation and amortization									7.2	8.6	10.2
Government Services | Operating Segments
Operating profit (loss)
Operating profit (loss)									(0.1)	(0.1)	(0.8)
Elimination of inter-segment revenues | Operating Segments
Revenues
Revenues									$ (122.4)	$ (127.7)	$ (147.1)

Segment and Geographic Inform_4

Segment and Geographic Information - Revenues by Geographic Region (Details) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Revenues
Revenues	$ 1,484.6	$ 1,394.1	$ 1,496	$ 1,612.9	$ 1,648	$ 1,647.9	$ 1,594.7	$ 1,607.9	$ 5,987.6	$ 6,498.6	$ 6,442.2
United States
Revenues
Revenues									5,625.1	6,025.2	5,997.4
All other countries
Revenues
Revenues									$ 362.5	$ 473.3	$ 444.8

Selected Quarterly Financial _3

Selected Quarterly Financial Data (Unaudited) - Financial Information (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2020	Jul. 31, 2020	Apr. 30, 2020	Jan. 31, 2020	Oct. 31, 2019	Jul. 31, 2019	Apr. 30, 2019	Jan. 31, 2019	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
Quarterly Financial Information Disclosure [Abstract]
Revenues	$ 1,484.6	$ 1,394.1	$ 1,496	$ 1,612.9	$ 1,648	$ 1,647.9	$ 1,594.7	$ 1,607.9	$ 5,987.6	$ 6,498.6	$ 6,442.2
Gross profit	242.4	219.2	189.9	179.2	194.7	193.9	180.5	162
Income (loss) from continuing operations	53.1	56	(136.8)	27.9	48.1	36.5	29.9	13	0.2	127.5	95.9
Income (loss) from discontinued operations, net of taxes	0	0	0	0.1	(0.1)	0.2	(0.2)	(0.1)	0.1	(0.1)	1.8
Net income (loss)	$ 53.1	$ 56	$ (136.8)	$ 28	$ 47.9	$ 36.8	$ 29.7	$ 13	$ 0.3	$ 127.4	$ 97.8
Net income (loss) per common share — Basic
Income (loss) from continuing operations (usd per share)	$ 0.79	$ 0.84	$ (2.05)	$ 0.42	$ 0.72	$ 0.55	$ 0.45	$ 0.20	$ 0	$ 1.92	$ 1.45
Income from discontinued operations (usd per share)	0	0	0	0	0	0	0	0	0	0	0.03
Net income (usd per share)	0.79	0.84	(2.05)	0.42	0.72	0.55	0.45	0.20	0	1.91	1.48
Net income (loss) per common share — Diluted
Income (loss) from continuing operations (usd per share)	0.78	0.83	(2.05)	0.41	0.71	0.55	0.45	0.20	0	1.91	1.45
Income from discontinued operations (usd per share)	0	0	0	0	0	0	0	0	0	0	0.03
Net income (usd per share)	$ 0.78	$ 0.83	$ (2.05)	$ 0.42	$ 0.71	$ 0.55	$ 0.45	$ 0.19	$ 0	$ 1.90	$ 1.47

Selected Quarterly Financial _4

Selected Quarterly Financial Data (Unaudited) - Footnote Disclosure (Details) $ / shares in Units, $ in Millions	3 Months Ended
	Apr. 30, 2020USD ($)$ / shares
Quarterly Financial Information Disclosure [Abstract]
Goodwill and intangible asset impairment	$ 172.8
Goodwill and intangible asset impairment, after tax	$ 170.6
Goodwill and intangible asset impairment (usd per share) | $ / shares	$ 2.54

Schedule II-Valuation and Qua_2

Schedule II-Valuation and Qualifying Accounts (Detail) - Accounts receivable allowances - USD ($) $ in Millions	12 Months Ended
	Oct. 31, 2020	Oct. 31, 2019	Oct. 31, 2018
SEC Schedule, 12-09, Movement in Valuation Allowances and Reserves [Roll Forward]
Balance Beginning of Year	$ 22.4	$ 19.2	$ 25.5
Charges to Costs and Expenses	96.3	87.7	57.4
Write-offs/Allowance Taken	(83.2)	(84.6)	(63.6)
Balance End of Year	$ 35.5	$ 22.4	$ 19.2