v3.19.2
revenue from contracts with customers - Contract assets (Details) - CAD ($)
$ in Millions
 3 Months Ended 6 Months Ended
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Jun. 30, 2018
Jun. 30, 2019
Dec. 31, 2018
Jun. 30, 2018
Contract assets              
Contract assets $ 0 $ 1,279 $ 1,475 $ 0 $ 1,441 $ 1,475 $ 1,272
Contract assets at beginning of period 0 1,279 1,475 0      
Net additions arising from operations 350 303 671 584      
Amounts billed in period and thus reclassified to accounts receivable (357) (313) (703) (617)      
Change in impairment allowance, net (2) 2 (4) 1      
Other 1 1 2 1      
Contract assets at end of period 1,441 1,272 1,441 1,272      
Reconciliation of contract assets presented in the Consolidated statements of financial position - current              
Gross contract assets         1,019   907
Reclassification to contract liabilities of contracts with contract assets less than contract liabilities         (5)   (5)
Reclassification from contract liabilities of contracts with contract liabilities less than contract assets         (155)   (142)
Current contract assets         859 860 760
Wireless segment              
Contract assets              
Amounts billed in period and thus reclassified to accounts receivable (330) (287) (650) (567)      
The twelve month period ending one year hence              
Contract assets              
Contract assets 1,019 907 1,017 907 1,019 1,017 907
Contract assets at beginning of period     1,017        
Contract assets at end of period 1,019 907 1,019 907      
The twelve month period ending two years hence              
Contract assets              
Contract assets 407 354 444 354 407 444 354
Contract assets at beginning of period     444        
Contract assets at end of period 407 354 407 354      
Thereafter              
Contract assets              
Contract assets 15 11 14 11 $ 15 $ 14 $ 11
Contract assets at beginning of period     14        
Contract assets at end of period $ 15 $ 11 $ 15 $ 11