Accrued Liabilities - Schedule of Accrued Liabilities (Detail) - USD ($) $ in Millions	Jun. 30, 2021	Dec. 31, 2020
Accrued Liabilities Current [Abstract]
Accrued capital expenditures	$ 28.1	$ 13.6
Accrued interest	18.0	18.0
Other accruals	16.6	22.5
Total	$ 62.7	$ 54.1

Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

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