Narrative (Details) $ in Millions	12 Months Ended
	Dec. 31, 2019 CAD ($)
Lessee, Lease, Description [Line Items]
Lessee, Operating lease, Option to extend	P10Y
Lessee, Operating lease, Option to terminate	P1Y
Operating lease, Residual value guarantee	$ 2
Minimum
Lessee, Lease, Description [Line Items]
Lessee, Operating And Finance leases, Remaining Lease Term	1 year
Maximum
Lessee, Lease, Description [Line Items]
Lessee, Operating And Finance leases, Remaining Lease Term	15 years