Fair Value Measurement - Carrying Value and Estimated Fair Value (Details) - USD ($) $ in Millions	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	$ 372.3	$ 386.7
Credit Facility, net of original discount on borrowings and deferred financing costs
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	354.2	371.2
Credit Facility, net of original discount on borrowings and deferred financing costs | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	354.2	371.2
Credit Facility, net of original discount on borrowings and deferred financing costs | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	354.2	371.2
Other obligations
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	18.1	15.5
Other obligations | Carrying Amount
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	18.1	15.4
Other obligations | Fair Value
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Long-term debt and lease obligation, including current maturities	$ 18.1	$ 15.4