Debt - Long-term Debt (Details) - USD ($) $ in Millions	Sep. 30, 2024	Dec. 31, 2023	Jul. 05, 2012
Debt Instrument [Line Items]
Long-term debt, gross	$ 203.0	$ 207.0
Less: unamortized debt issuance costs	0.4	0.2
Total debt	202.6	206.8
Less: current portion of long-term debt	0.0	134.0
Long-term debt, net	$ 202.6	72.8
Term Loan, due July 2, 2027 (6.67%)
Debt Instrument [Line Items]
Debt instrument, stated interest rate	6.67%
Long-term debt, gross	$ 130.0	0.0
Term Loan, due December 31, 2024 (6.32%)
Debt Instrument [Line Items]
Debt instrument, stated interest rate	6.32%
Long-term debt, gross	$ 0.0	81.0
Series B notes, due July 5, 2024 (3.82%)
Debt Instrument [Line Items]
Debt instrument, stated interest rate	3.82%		3.82%
Long-term debt, gross	$ 0.0	53.0
Series C notes, due July 5, 2027 (4.02%)
Debt Instrument [Line Items]
Debt instrument, stated interest rate	4.02%
Long-term debt, gross	$ 73.0	$ 73.0