PROPERTY, PLANT AND EQUIPMENT - Schedule of Property, Plant and Equipment (Details) - CAD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Total property, plant and equipment	$ 126,040	$ 118,450
Total accumulated depreciation	(25,973)	(23,879)
Property, plant and equipment, net	$ 100,067	94,571
Pipelines
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	2.80%
Total property, plant and equipment	$ 62,997	57,459
Facilities and equipment
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	3.10%
Total property, plant and equipment	$ 34,331	30,149
Land and right-of-way
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	2.30%
Total property, plant and equipment	$ 3,320	2,896
Gas mains, services and other
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	2.70%
Total property, plant and equipment	$ 13,606	12,813
Storage
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	2.40%
Total property, plant and equipment	$ 3,099	2,936
Wind turbines, solar panels and other
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	4.00%
Total property, plant and equipment	$ 4,912	4,877
Other
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	8.20%
Total property, plant and equipment	$ 1,507	1,558
Under construction
Property, Plant and Equipment [Line Items]
Weighted Average Depreciation Rate (percent)	0.00%
Total property, plant and equipment	$ 2,268	$ 5,762