| Fair value of financial instruments |
| | Fair Value as at November 30, 2021 | | | | Carrying Amount | | | Fair Value | | | Level in the hierarchy | | Instruments carried at amortized cost: | | | | | | | | | | Long-term debt | | $ | 4,204,573 | | | $ | 4,219,305 | | | Level 2 | |
| | Fair Value at February 28, 2021 | | | | Carrying Amount | | | Fair Value | | | Level in the hierarchy | | Instruments carried at amortized cost: | | | | | | | | | | Long-term debt | | $ | 2,454,123 | | | $ | 2,464,540 | | | Level 2 | |
|