Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2024	Dec. 31, 2023
Fair Value Inputs, Liabilities, Quantitative Information
Long-term Debt, Gross	$ 1,047.5	$ 1,048.8
Long-term debt	$ 1,036.3	$ 1,036.6
Fair Value, Inputs, Level 1
Fair Value Inputs, Liabilities, Quantitative Information
Fair value level 1 inputs	Level 1 inputs