Amount of short-term debt and current maturity of long-term debt and capital lease obligations due within one year or the normal operating cycle, if longer.

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- Definition

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	instant

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The total amount of the contingent obligation under letters of credit outstanding as of the reporting date.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ References

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of borrowing capacity currently available under the credit facility (current borrowing capacity less the amount of borrowings outstanding).

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of short-term borrowings, long-term debt and capital leases due or subject to remarketing within the next twelve months, including amounts classified as current and amounts classified as noncurrent due to intent and ability to refinance.

+ References

No definition available.

+ Details

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Namespace Prefix:	wm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

+ References

No definition available.

+ Details

Name:	wm_DebtAndCapitalLeasesMaturingOrSubjectToRemarketingWithinNextTwelveMonthsClassifiedAsLongTerm
Namespace Prefix:	wm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represent debt with interest rate periods that expire within the next 12 months.

+ References

No definition available.

+ Details

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Namespace Prefix:	wm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the period of time for the extension.

+ References

No definition available.

+ Details

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Namespace Prefix:	wm_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

The accordion option increase above the current maximum borrowing capacity under the credit facility.

+ References

No definition available.

+ Details

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Namespace Prefix:	wm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Represents the number of extension periods.

+ References

No definition available.

+ Details

Name:	wm_NumberOfExtensions
Namespace Prefix:	wm_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	instant

- Definition

Maximum borrowing capacity under a term loan without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

No definition available.

+ Details

Name:	wm_TermLoanMaximumBorrowingAmount
Namespace Prefix:	wm_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Details

Name:	us-gaap_DebtInstrumentAxis=wm_CommercialPaperProgramMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

Name:	us-gaap_DebtInstrumentAxis=wm_TaxExemptBondsMember
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- Details

Name:	us-gaap_DebtInstrumentAxis=wm_CanadianRevolvingCreditFacilityMember
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- Details

Name:	us-gaap_DebtInstrumentAxis=wm_CanadianTermLoanMember
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Name:	us-gaap_DebtInstrumentAxis=wm_OtherLetterOfCreditFacilitiesMember
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Data Type:	na
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Name:	us-gaap_DebtInstrumentAxis=wm_CapitalLeasesAndOtherMember
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Debt - Classification and Utilization (Detail) $ in Millions, $ in Millions	9 Months Ended
	Sep. 30, 2018 CAD ($) item	Sep. 30, 2018 USD ($) item	Jul. 31, 2018 CAD ($)	May 31, 2018 USD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt
Debt maturing or subject to remarketing within twelve months		$ 2,200
Current portion of long-term debt		447				$ 739
Commercial Paper Program [Member]
Debt
Debt maturing or subject to remarketing within twelve months classified as long-term		955
Maximum capacity		2,750			$ 1,500
Debt, before unamortized (discount) premium		1,100
Debt term	397 days
Tax Exempt Bonds [Member]
Debt
Debt with interest rate periods that expire in the next 12 months		806
Current portion of long-term debt		209
Debt maturing or subject to remarketing within twelve months classified as long-term		761
Variable-rate tax-exempt bonds		268
Canadian Revolving Credit Facility [Member]
Debt
Maximum capacity			$ 50
Canadian Term Loan [Member]
Debt
Maximum term credit			$ 460
Other Letter of Credit Facilities [Member]
Debt
Letters of credit outstanding		541
Capital Leases and Other [Member]
Debt
Current portion of long-term debt		260
Revolving Credit Facility [Member]
Debt
Maximum capacity		2,750		$ 2,250
Accordion option capacity		$ 750
Number of extension periods \| item	2	2
Extension term	1 year
Letters of credit outstanding		$ 606
Unused and available credit capacity		1,000
Credit Facility Revolving, Canadian [Member]
Debt
Maximum capacity		375
Outstanding borrowings under credit facility	$ 57	$ 44