Properties - Capital Leases Included in Properties (Details) - CAD ($) $ in Millions	Dec. 31, 2022	Dec. 31, 2021
Finance Leased Assets [Line Items]
Cost	$ 180	$ 300
Accumulated depreciation	78	134
Net book value	102	166
Rolling stock
Finance Leased Assets [Line Items]
Cost	170	291
Accumulated depreciation	75	133
Net book value	95	158
Other
Finance Leased Assets [Line Items]
Cost	10	9
Accumulated depreciation	3	1
Net book value	$ 7	$ 8