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Fair Value Measurements - Recurring Basis (Details) - Fair Value, Recurring - Level 2 - USD ($) $ in Millions | 12 Months Ended
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Dec. 31, 2020 | Dec. 31, 2019
Assets and (Liabilities) at Fair Value |  |
Liabilities at fair value | $ 4.0 | $ 1.7
Interest rate contracts |  |
Assets and (Liabilities) at Fair Value |  |
Loss recorded to net finance costs | $ 2.0 | $ (0.7)

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- Definition Fair value of financial and nonfinancial obligations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=117815213&loc=d3e19207-110258 + Details
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