summary of significant accounting policies - Inventories (Details) - CAD ($) $ in Millions	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Inventory
Mobile handsets, parts and accessories	$ 381	$ 328
Costs of goods sold	$ 2,200	$ 2,000

The amount of all expenses directly or indirectly attributed to the goods or services sold. Attributed expenses include, but are not limited to, costs previously included in the measurement of inventory that has now been sold, such as depreciation and maintenance of factory buildings and equipment used in the production process, unallocated production overheads, and abnormal amounts of production costs of inventories.

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Reference 2: http://www.xbrl.org/2003/role/disclosureRef
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