Common Shares - Additional Information (Detail) - shares |
6 Months Ended | |||
---|---|---|---|---|
Jun. 30, 2018 |
Jun. 27, 2018 |
Jun. 13, 2018 |
Jun. 13, 2017 |
|
Class of Stock [Line Items] | ||||
Exxon Mobil Corporation's ownership interest in Imperial | 69.60% | |||
Normal course issuer bid share repurchase shares authorized | 42,326,545 | 40,391,196 | ||
Percent of total shares | 5.00% | 5.00% | ||
Normal course issuer bid share repurchase term, months | 12 months |