Acquisitions (Narrative) (Detail)	3 Months Ended	12 Months Ended
Mar. 31, 2020 USD ($) entity	Mar. 31, 2019 USD ($) entity	Mar. 31, 2020 USD ($) entity	Mar. 31, 2020 USD ($)
Acquisitions [Abstract]
Number of immaterial businesses acquired in period \| entity	1	3
Acquisition-related costs	$ 1,146,000	$ 837,000
Goodwill expected to be deductible for tax purposes	$ 3,482,000	$ 4,446,000	$ 3,482,000	$ 3,482,000
Fair value of acquired working capital is provisional			4	4

The amount of goodwill arising from a business combination that is expected to be deductible for tax purposes.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 30
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=35744584&loc=d3e6927-128479

+ Details

Name:	us-gaap_BusinessAcquisitionPurchasePriceAllocationGoodwillExpectedTaxDeductibleAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

This element represents acquisition-related costs incurred to effect a business combination which costs have been expensed during the period. Such costs include finder's fees; advisory, legal, accounting, valuation, and other professional or consulting fees; general administrative costs, including the costs of maintaining an internal acquisitions department; and may include costs of registering and issuing debt and equity securities.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 805
-SubTopic 10
-Section 25
-Paragraph 23
-URI http://asc.fasb.org/extlink&oid=116868678&loc=d3e1043-128460

+ Details

Name:	us-gaap_BusinessCombinationAcquisitionRelatedCosts
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- References

No definition available.

+ Details

Name:	us-gaap_BusinessCombinationsAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

The number of businesses acquired by the entity during the period.

+ References

No definition available.

+ Details

Name:	us-gaap_NumberOfBusinessesAcquired
Namespace Prefix:	us-gaap_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration

- Definition

This element represents the number of acquisitions for which the initial accounting is incomplete.

+ References

No definition available.

+ Details

Name:	wcn_BusinessCombinationProvisionalInformationInitialAccountingIncompleteNumberOfAcquisitions
Namespace Prefix:	wcn_
Data Type:	xbrli:integerItemType
Balance Type:	na
Period Type:	duration