CHANGES IN ACCOUNTING POLICIES (Details) - CAD CAD in Millions	Dec. 31, 2016	Dec. 31, 2015
CHANGES IN ACCOUNTING POLICIES
Deferred amounts and other assets	CAD 3,113	CAD 3,160
Long-term debt	CAD 36,494	39,391
Accounting Standards Update 2015-03 \| Adjustments
CHANGES IN ACCOUNTING POLICIES
Deferred amounts and other assets		(149)
Long-term debt		CAD (149)

Amount of long-term debt and capital lease obligation due after one year or beyond the normal operating cycle, if longer.

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

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