Fair Value Measurements (Details) - USD ($) $ in Millions	Jun. 30, 2022	Dec. 31, 2021
Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
COLI asset	$ 9.6	$ 10.8
Level 2 | 2025 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note, debt instrument	43.2	59.6
Level 2 | 2026 Notes
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Note, debt instrument	308.8	363.6
Money market funds | Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash and cash equivalents	$ 22.5	$ 12.1