Reportable Business Segments (Assets by Segment) (Details) - USD ($) $ in Millions	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Segment Reporting Information [Line Items]
Total assets	$ 3,471.8	$ 2,798.3	$ 2,567.6
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Total assets	1,626.0	1,449.4	1,456.4
Commercial Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Total assets	1,052.6	989.2	730.3
Corporate Segment and Other Operating Segment [Member]
Segment Reporting Information [Line Items]
Total assets	$ 793.2	$ 359.7	$ 380.9