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Maximum potential amount of future payments (undiscounted) the guarantor could be required to make under the guarantee or each group of similar guarantees before reduction for potential recoveries under recourse or collateralization provisions.

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Expenses recognized resulting from transactions (excluding transactions that are eliminated in consolidated or combined financial statements) with related party.

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Related Party Transactions - Management and Other Transactions (Details) $ in Millions, $ in Millions	12 Months Ended
	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)	Dec. 31, 2019 USD ($)	Dec. 31, 2021 CAD ($)	Dec. 31, 2020 CAD ($)
Management \| Equipment, Supplies And Services
Related Party Transaction [Line Items]
Payments, related party	$ 81.2	$ 80.9	$ 108.0
Payables, related party	0.6	8.9
Revenue, related party	4.2	4.1	$ 2.3
Receivables, related party	0.4	0.5
Proportionately Consolidated Non-Controlled Joint Venture \| Performance and Payment Bonds
Related Party Transaction [Line Items]
Outstanding bonds, amount	$ 7.7	$ 20.7		$ 9.7	$ 26.4