SUBSEQUENT EVENTS (Details) $ in Millions		12 Months Ended
	Jan. 15, 2019 CAD ($)	Dec. 31, 2018 CAD ($)	Dec. 31, 2017 CAD ($)	Dec. 31, 2016 CAD ($)	Jan. 08, 2019 $ / CAD_dollar_per_principal
SUBSEQUENT EVENTS
Payments to acquire property, plant, and equipment		$ 6,806	$ 8,287	$ 5,128
Subsequent Event
SUBSEQUENT EVENTS
Percentage of assets acquired	100.00%
Payments to acquire property, plant, and equipment	$ 265
Enbridge Energy Partners and Spectra Energy Partners | Subsequent Event
SUBSEQUENT EVENTS
Notes payable, cash payment per $1,000 principal amount | $ / CAD_dollar_per_principal					1.00