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
Balance Type:	credit
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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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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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 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

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

The portion of short-term borrowings, current maturities of long-term debt and capital lease obligations and borrowings subject to refinancing within the next twelve months, classified as long-term obligations due to the intent and ability to refinance on a long-term basis.

+ References

No definition available.

+ Details

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

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

- Details

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- Details

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- Details

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- Details

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Data Type:	na
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- Details

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

Name:	us-gaap_DebtInstrumentAxis=wm_OtherLetterOfCreditFacilitiesMember
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- Details

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Debt - Classification and Utilization (Detail) $ in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2018 CAD ($)	Mar. 31, 2018 USD ($)	Dec. 31, 2017 USD ($)
Debt
Debt maturing within twelve months		$ 2,180
Current portion of long-term debt		1,056	$ 739
Debt classified as long-term due to intent and ability to refinance on long-term basis		1,124
Commercial Paper Program [Member]
Debt
Current portion of long-term debt		989
Maximum capacity		1,500
Debt, before unamortized (discount) premium		990
Debt term	397 days
Tax Exempt Bonds [Member]
Debt
Current portion of long-term debt		181
Debt with interest rate periods that expiring in the next 12 months		831
Variable-rate tax-exempt bonds		328
Revolving Credit Facility [Member]
Debt
Current portion of long-term debt		28
Maximum capacity		2,250
Outstanding borrowings under credit facility		28
Letters of credit outstanding		603
Unused and available credit capacity		629
Canadian Revolving Credit Facility [Member]
Debt
Maximum capacity	$ 50
Outstanding borrowings under credit facility		0
Letters of credit outstanding		0
Canadian Term Loan [Member]
Debt
Current portion of long-term debt	128	99
Outstanding borrowings under credit facility	128	99
Maximum term credit	$ 460
Other Letter of Credit Facilities [Member]
Debt
Letters of credit outstanding		511
Other Debt [Member]
Debt
Current portion of long-term debt		$ 233