SIGNIFICANT ACCOUNTING POLICIES (Details) $ in Millions	12 Months Ended
Dec. 31, 2018 CAD ($) reporting_unit	Dec. 31, 2017 CAD ($)	Dec. 31, 2016 CAD ($)
Cash and Cash Equivalents [Line Items]
Net cash (used in) provided by financing activities	$ (7,503)	$ 3,476	$ 840
Number of reporting units \| reporting_unit	2
Restatement Adjustment
Cash and Cash Equivalents [Line Items]
Net cash (used in) provided by financing activities			$ 300

Amount of cash inflow (outflow) from financing activities, including discontinued operations. Financing activity cash flows include obtaining resources from owners and providing them with a return on, and a return of, their investment; borrowing money and repaying amounts borrowed, or settling the obligation; and obtaining and paying for other resources obtained from creditors on long-term credit.

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 24
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3521-108585

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