Reportable Business Segments (Capital Expenditures by Segment) (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2025	Sep. 30, 2024	Sep. 30, 2025	Sep. 30, 2024
Segment Reporting Information [Line Items]
Payments to Acquire Property, Plant, and Equipment	$ 35.6	$ 41.2	$ 89.6	$ 103.4
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Payments to Acquire Property, Plant, and Equipment	7.2	16.8	30.4	45.6
Commercial Heating and Cooling
Segment Reporting Information [Line Items]
Payments to Acquire Property, Plant, and Equipment	22.0	17.5	34.5	39.7
Corporate & Other
Segment Reporting Information [Line Items]
Payments to Acquire Property, Plant, and Equipment	$ 6.4	$ 6.9	$ 24.7	$ 18.1