Changes in Accumulated Other Comprehensive Income (Loss) (Detail) - CAD CAD in Millions |
3 Months Ended | 9 Months Ended | ||
|---|---|---|---|---|
Sep. 30, 2016 |
Sep. 30, 2015 |
Sep. 30, 2016 |
Sep. 30, 2015 |
|
| Accumulated Other Comprehensive Income (Loss) [Line Items] | ||||
| Balance at January 1 | CAD (1,828) | CAD (2,059) | ||
| Current period change excluding amounts reclassified from accumulated other comprehensive income | 100 | (176) | ||
| Amounts reclassified from accumulated other comprehensive income | CAD 34 | CAD 42 | 108 | 126 |
| Balance at September 30 | CAD (1,620) | CAD (2,109) | CAD (1,620) | CAD (2,109) |