Debt - Debt Issuance Costs (Details) - USD ($) $ in Millions	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Capitalized deferred debt issuance costs			$ 3.6
Write off of deferred debt issuance costs			$ 0.5
Deferred debt issuance costs	$ 4.6	$ 5.9
Expected Future Amortization Expense [Abstract]
2021	1.3
2022	1.3
2023	1.1
2024	0.4
2025	0.4
Thereafter	0.1
Total	4.6	5.9
Interest expense
Debt Instrument [Line Items]
Amortization expense	$ 1.3	$ 1.2

Deferred Debt Issuance Costs, Expected Future Amortization Expense After Year Five

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Deferred Debt Issuance Costs, Expected Future Amortization Expense in Next Twelve Months

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Deferred Debt Issuance Costs, Expected Future Amortization Expense in Year Five

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Deferred Debt Issuance Costs, Expected Future Amortization Expense in Year Four

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Deferred Debt Issuance Costs, Expected Future Amortization Expense in Year Three

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Deferred Debt Issuance Costs, Expected Future Amortization Expense in Year Two

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Amount of amortization expense attributable to debt issuance costs.

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Amount, before accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs.

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Write-off of amounts previously capitalized as debt issuance cost in an extinguishment of debt.

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