COMMITMENTS AND CONTINGENCIES - COMMITMENTS (Details) $ in Millions	Dec. 31, 2021 CAD ($)
Annual debt maturities
Total	$ 73,809
Less than 1 year	6,164
2 years	7,910
3 years	4,559
4 years	4,357
5 years	11,007
Thereafter	39,812
Interest obligations
Total	36,044
Less than 1 year	2,531
2 years	2,389
3 years	2,229
4 years	2,073
5 years	1,925
Thereafter	24,897
Purchase of services, pipe and other materials, including transportation
Total	7,876
Less than 1 year	2,945
2 years	1,010
3 years	736
4 years	561
5 years	607
Thereafter	2,017
Maintenance agreements
Total	346
Less than 1 year	41
2 years	20
3 years	20
4 years	21
5 years	21
Thereafter	223
Right-of-ways commitments
Total	1,249
Less than 1 year	35
2 years	35
3 years	35
4 years	36
5 years	37
Thereafter	1,071
Total
Total	119,324
Less than 1 year	11,716
2 years	11,364
3 years	7,579
4 years	7,048
5 years	13,597
Thereafter	$ 68,020