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Debt and Financing Arrangements (Details) - USD ($) | 12 Months Ended |
--- | --- | ---
Dec. 31, 2018 | Dec. 31, 2017 | Oct. 15, 2018
Debt Instrument [Line Items] |  |  |
Interest expense | $ 800,000 | $ 3,000,000.0 |
Revolver |  |  |
Debt Instrument [Line Items] |  |  |
Amount outstanding | 0 |  |
Principal amount |  |  | $ 150,000,000
Additional principal amount available (up to) |  |  | 100,000,000
Swing loans |  |  |
Debt Instrument [Line Items] |  |  |
Additional principal amount available (up to) |  |  | 20,000,000
Letters of Credit |  |  |
Debt Instrument [Line Items] |  |  |
Additional principal amount available (up to) |  |  | $ 20,000,000
Term Loan and Revolving Facility |  |  |
Debt Instrument [Line Items] |  |  |
Extinguishment of debt amount | 78,000,000.0 | $ 107,600,000 |
Amount outstanding | $ 0 |  |

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