condensed interim consolidated financial statements (Details) - CAD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2018	Jun. 30, 2017	Jun. 30, 2018	Jun. 30, 2017	Dec. 31, 2017	Jan. 01, 2017
condensed interim consolidated financial statements
Wireless handsets, parts and accessories	$ 268		$ 268		$ 322	$ 268
Costs of goods sold	$ 469	$ 446	$ 936	$ 854

The amount of costs relating to expenses directly or indirectly attributed to the goods or services sold, which may include, but are not limited to, costs previously included in the measurement of inventory that has now been sold, unallocated production overheads and abnormal amounts of production costs of inventories.

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