Debt - Schedule of Maturities of Company's Debt (Details) - USD ($) $ in Millions	Dec. 31, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
2021	$ 0.0
2022	4.1
2023	25.0
2024	0.0
2025	0.0
Thereafter	25.0
Total	54.1
Loan Notes \| Loan Notes due 2023
Debt Instrument [Line Items]
2021	0.0
2022	0.0
2023	25.0
2024	0.0
2025	0.0
Thereafter	0.0
Total	25.0	$ 25.0
Loan Notes \| Loan Notes due 2026
Debt Instrument [Line Items]
2021	0.0
2022	0.0
2023	0.0
2024	0.0
2025	0.0
Thereafter	25.0
Total	25.0	25.0
Revolving credit facility
Debt Instrument [Line Items]
2021	0.0
2022	4.1
2023	0.0
2024	0.0
2025	0.0
Thereafter	0.0
Total	$ 4.1	$ 17.5

Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

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Amount of long-term debt payable, sinking fund requirement, and other securities issued that are redeemable by holder at fixed or determinable price and date, maturing after fifth fiscal year following current fiscal year. Excludes interim and annual periods when interim periods are reported from current statement of financial position date (rolling approach).

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