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Fair Value Measurements - Summary of Fair Value Hierarchy for Assets (Details) - CAD ($) $ in Millions | Dec. 31, 2020 | Dec. 31, 2019
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Disclosure of fair value measurement of assets and liabilities [line items] |  |
Assets | $ 174.9 | $ 153.0
Recurring fair value measurement | Interest rate swap |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Liabilities | 6.9 |
Recurring fair value measurement | Investments held for self-insured liabilities |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Assets | 174.9 |
Recurring fair value measurement | Level 1 | Interest rate swap |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Liabilities | 0.0 |
Recurring fair value measurement | Level 1 | Investments held for self-insured liabilities |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Assets | 0.0 |
Recurring fair value measurement | Level 2 | Interest rate swap |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Liabilities | 6.9 |
Recurring fair value measurement | Level 2 | Investments held for self-insured liabilities |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Assets | 174.9 |
Recurring fair value measurement | Level 3 | Interest rate swap |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Liabilities | 0.0 |
Recurring fair value measurement | Level 3 | Investments held for self-insured liabilities |  |
Disclosure of fair value measurement of assets and liabilities [line items] |  |
Assets | $ 0.0 |

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- Definition The amount of financial assets that the entity does not separately disclose in the same statement or note. [Refer: Financial assets] + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name IAS -Number 1 -IssueDate 2020-01-01 -Paragraph 54 -Subparagraph d -URI http://eifrs.ifrs.org/eifrs/xifrs-link?type=IAS&num=1&code=ifrs-tx-2020-en-r&anchor=para_54_d&doctype=Standard -URIDate 2020-01-01 + Details
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