Debt - CASHMAX Secured Borrowing Facility (Details) $ in Millions	Nov. 30, 2018 CAD ($)
Receivables Securitization Facility \| CASHMAX \| Variable Interest Entity, Primary Beneficiary
Debt Instrument [Line Items]
Maximum borrowing amount	$ 25

The transferor's maximum amount of exposure to loss as a result of its continuing involvement in transferred financial assets.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 860
-SubTopic 20
-Section 50
-Paragraph 4
-Subparagraph (a)(4)(ii)
-URI http://asc.fasb.org/extlink&oid=121570589&loc=d3e107314-111719

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