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Share-based Payments Arrangement - CHIEF's Employee Stock Options Outstanding (Detail) - CHIEF Telecom Inc. (CHIEF) [Member] | 12 Months Ended |  |  |  |  |  |  |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Dec. 31, 2019 $ / shares | Dec. 31, 2018 $ / shares | Jun. 30, 2019 $ / shares | Aug. 31, 2018 $ / shares | Jul. 31, 2018 $ / shares | Jun. 30, 2018 $ / shares | Dec. 31, 2017 $ / shares | Dec. 19, 2017 $ / shares | Dec. 31, 2016 $ / shares
Granted on October 22, 2015 [Member] |  |  |  |  |  |  |  |  |
Disclosure of range of exercise prices of outstanding share options [Line Items] |  |  |  |  |  |  |  |  |
Range of Exercise Price | $ 34.40 | $ 34.40 |  |  |  |  |  |  |
Number of Options Outstanding | 314.25 | 882.75 |  |  |  |  | 1,936.00 |  | 1,948.00
Weighted-average Remaining Contractual Life (Years) | 9 months 21 days | 1 year 9 months 21 days |  |  |  |  |  |  |
Weighted-average Exercise Price | $ 34.40 | $ 34.40 |  |  |  |  | $ 34.40 |  | $ 34.40
Options Exercisable Number of Options | 314.25 | 416.50 |  |  |  |  | 968.00 |  |
Option Exercisable Weighted-average Exercise Price | $ 34.40 | $ 34.40 |  |  |  |  | $ 34.40 |  |
Granted on December 19, 2017 [Member] |  |  |  |  |  |  |  |  |
Disclosure of range of exercise prices of outstanding share options [Line Items] |  |  |  |  |  |  |  |  |
Range of Exercise Price | $ 135.60 | $ 140.60 | $ 135.60 | $ 140.60 | $ 144.10 | $ 144.10 |  | $ 147.00 |
Number of Options Outstanding | 897.00 | 925.00 |  |  |  |  | 950.00 |  | 0
Weighted-average Remaining Contractual Life (Years) | 2 years 11 months 15 days | 3 years 11 months 15 days |  |  |  |  |  |  |
Weighted-average Exercise Price | $ 135.60 | $ 140.60 |  |  |  |  | $ 147.00 |  | $ 0
Options Exercisable Number of Options | 448.50 | 0 |  |  |  |  | 0 |  |
Option Exercisable Weighted-average Exercise Price | $ 135.60 | $ 0 |  |  |  |  | $ 0 |  |
Granted on October 31, 2018 [Member] |  |  |  |  |  |  |  |  |
Disclosure of range of exercise prices of outstanding share options [Line Items] |  |  |  |  |  |  |  |  |
Range of Exercise Price | $ 141.70 | $ 147.00 | $ 141.70 |  |  |  |  |  |
Number of Options Outstanding | 46.00 | 50.00 |  |  |  |  | 0 |  |
Weighted-average Remaining Contractual Life (Years) | 3 years 9 months 29 days | 4 years 9 months 29 days |  |  |  |  |  |  |
Weighted-average Exercise Price | $ 141.70 | $ 147.00 |  |  |  |  | $ 0 |  |
Options Exercisable Number of Options | 0 | 0 |  |  |  |  |  |  |
Option Exercisable Weighted-average Exercise Price | $ 0 | $ 0 |  |  |  |  |  |  |

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