Stock Compensation - Additional Information (Details) - USD ($) $ / shares in Units, $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Stock compensation
Weighted-average grant-date fair value (in dollars per share)	$ 43.22	$ 31.18	$ 37.56
Unrecognized stock-based compensation expense, options	$ 26.8
Stock Options
Stock compensation
Stock-based compensation expense	20.9	$ 23.5	$ 23.4
Stock-based compensation expense capitalized into inventory	$ 0.6
Weighted-average period over which remaining unrecognized compensation cost will be recognized	2 years
RSUs
Stock compensation
Stock-based compensation expense	$ 7.0	$ 2.4	$ 0.6
Stock-based compensation expense capitalized into inventory	$ 0.2
Weighted-average period over which remaining unrecognized compensation cost will be recognized	2 years 10 months 24 days
Unrecognized stock-based compensation expense, RSUs	$ 15.6

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Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

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Amount of cost to be recognized for nonvested award under share-based payment arrangement. Excludes share and unit options.

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The weighted average grant-date fair value of options granted during the reporting period as calculated by applying the disclosed option pricing methodology.

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