Derivative Instruments and Hedging Activities - Fair Value Balance Sheet (Details) $ in Millions	Jun. 30, 2023 CAD ($)	Jun. 30, 2023 USD ($)	Dec. 31, 2022 USD ($)
Derivatives designated as hedging instruments
Derivative asset, fair value, designated as hedging instrument		$ 31.9	$ 47.8
Derivative liability, fair value, designated as hedging instrument		(1.8)	(0.2)
Derivatives not designated as hedging instruments
Derivative asset, not designated as hedging instrument, fair value		23.6	94.3
Derivative liability, not designated as hedging instrument, fair value		(67.6)	(25.3)
Forward starting interest rate swaps | Designated as hedging instruments | Cash flow hedges
Derivatives designated as hedging instruments
Notional amount		1,000.0	1,000.0
Derivatives not designated as hedging instruments
Notional amount		1,000.0	1,000.0
Foreign currency forwards | Designated as hedging instruments | Cash flow hedges
Derivatives designated as hedging instruments
Notional amount		238.6	176.6
Derivatives not designated as hedging instruments
Notional amount		238.6	176.6
Foreign currency forwards | Not designated as hedging instruments
Derivatives designated as hedging instruments
Notional amount	$ 260,000,000	194.7
Derivatives not designated as hedging instruments
Notional amount	$ 260,000,000	194.7
Commodity swaps | Not designated as hedging instruments
Derivatives designated as hedging instruments
Notional amount		678.6	525.2
Derivatives not designated as hedging instruments
Notional amount		678.6	525.2
Commodity options | Not designated as hedging instruments
Derivatives designated as hedging instruments
Notional amount		19.7	19.7
Derivatives not designated as hedging instruments
Notional amount		19.7	19.7
Other non-current assets | Forward starting interest rate swaps
Derivatives designated as hedging instruments
Derivative asset, fair value, designated as hedging instrument		29.3	40.0
Other non-current assets | Foreign currency forwards
Derivatives designated as hedging instruments
Derivative asset, fair value, designated as hedging instrument		0.2	1.6
Other non-current assets | Commodity swaps
Derivatives not designated as hedging instruments
Derivative asset, not designated as hedging instrument, fair value		0.8	7.4
Other current assets | Foreign currency forwards
Derivatives designated as hedging instruments
Derivative asset, fair value, designated as hedging instrument		2.4	6.2
Derivatives not designated as hedging instruments
Derivative asset, not designated as hedging instrument, fair value		2.6
Other current assets | Commodity swaps
Derivatives not designated as hedging instruments
Derivative asset, not designated as hedging instrument, fair value		18.9	86.1
Other current assets | Commodity options
Derivatives not designated as hedging instruments
Derivative asset, not designated as hedging instrument, fair value		1.3	0.8
Other liabilities | Forward starting interest rate swaps
Derivatives designated as hedging instruments
Derivative liability, fair value, designated as hedging instrument		0.0	0.0
Other liabilities | Foreign currency forwards
Derivatives designated as hedging instruments
Derivative liability, fair value, designated as hedging instrument		(1.1)	(0.1)
Other liabilities | Commodity swaps
Derivatives not designated as hedging instruments
Derivative liability, not designated as hedging instrument, fair value		(18.2)	(10.4)
Accounts payable and other current liabilities | Foreign currency forwards
Derivatives designated as hedging instruments
Derivative liability, fair value, designated as hedging instrument		(0.7)	(0.1)
Derivatives not designated as hedging instruments
Derivative liability, not designated as hedging instrument, fair value		(0.7)
Accounts payable and other current liabilities | Commodity swaps
Derivatives not designated as hedging instruments
Derivative liability, not designated as hedging instrument, fair value		(47.4)	(14.1)
Accounts payable and other current liabilities | Commodity options
Derivatives not designated as hedging instruments
Derivative liability, not designated as hedging instrument, fair value		$ (1.3)	$ (0.8)