Financial Instruments and Risk Management - Cash and Cash Equivalents (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Financial Instruments [Abstract]
Cash	$ 384.4	$ 447.0
Cash equivalents	9.6	16.8
Cash and cash equivalents	$ 394.0	$ 463.8	$ 479.5	$ 422.0

Financial Instruments [Abstract]

No definition available.

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- Definition

The amount of cash on hand and demand deposits. [Refer: Cash on hand]

+ References

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- Definition

The amount of cash on hand and demand deposits, along with short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value. [Refer: Cash; Cash equivalents]

+ References

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- Definition

The amount of short-term, highly liquid investments that are readily convertible to known amounts of cash and that are subject to an insignificant risk of changes in value.

+ References

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