Debt and Credit Facility - Summary of Interest Relating to Senior Notes and Revolving Credit Facility (Details) - USD ($) $ in Millions	3 Months Ended	6 Months Ended
Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Debt Instrument [Line Items]
Total interest expense	$ 12.2	$ 12.4	$ 24.4	$ 24.7
Senior Notes and Revolving Credit Facility
Debt Instrument [Line Items]
Interest expense capitalized as construction in progress	(0.8)	(0.3)	(1.4)	(0.4)
Total interest expense	12.2	12.4	24.4	24.7
Revolving Credit Facility
Debt Instrument [Line Items]
Revolving Credit Facility commitment fees and finance cost amortization	0.6	0.5	1.0	0.9
Senior Notes
Debt Instrument [Line Items]
Senior Notes interest expense, including debt issuance cost amortization	$ 12.4	$ 12.2	$ 24.8	$ 24.2

Debt related commitment fees and amortization of financing costs.

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Amount of the cost of borrowed funds accounted for as interest expense.

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Aggregate amount of interest paid or due on all long-term debt.

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