Fair Value Measurements (Fair Value Inputs, Liabilities, Quantitative Information) (Details) - USD ($) $ in Millions	6 Months Ended
	Jun. 30, 2023	Dec. 31, 2022
Fair Value Inputs, Liabilities, Quantitative Information
Long-term Debt, Gross	$ 1,040.8	$ 1,072.3
Long-term debt	$ 1,035.7	$ 1,066.6
Fair Value, Inputs, Level 1 [Member]
Fair Value Inputs, Liabilities, Quantitative Information
Fair value level 1 inputs	Level 1 inputs