Reportable Business Segments (Equity Method Investments) (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]
Total income from equity method investments	$ 2.5	$ 2.4	$ 5.8	$ 6.1
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Total income from equity method investments	(2.4)	(1.1)	(4.8)	(3.7)
Commercial Heating and Cooling
Segment Reporting Information [Line Items]
Total income from equity method investments	(0.3)	(1.1)	(1.1)	(2.3)
Corporate & Other
Segment Reporting Information [Line Items]
Total income from equity method investments	$ 0.2	$ (0.2)	$ 0.1	$ (0.1)