Leases Maturities of Lease Liabilities (Details) $ in Millions	Dec. 31, 2021 CAD ($)
Finance Leases
2022	$ 107
2023	9
2024	9
2025	9
2026	9
Thereafter	7
Total lease payments	150
Imputed interest	(10)
Present value of lease payments	140
Operating Leases
2022	66
2023	62
2024	50
2025	39
2026	34
Thereafter	60
Total lease payments	311
Imputed interest	(28)
Present value of lease payments	$ 283