Reportable Business Segments (Equity Method Investments) (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2026	Jun. 30, 2025	Jun. 30, 2026	Jun. 30, 2025
Segment Reporting Information [Line Items]
Total income from equity method investments	$ 1.0	$ 2.1	$ 0.6	$ 3.3
Operating Segments
Segment Reporting Information [Line Items]
Total income from equity method investments	0.6	(2.1)	(0.6)	(3.2)
Corporate and Other
Segment Reporting Information [Line Items]
Total income from equity method investments	(1.6)	0.0	0.0	(0.1)
Residential Heating and Cooling [Member] | Operating Segments
Segment Reporting Information [Line Items]
Total income from equity method investments	0.4	(1.7)	(0.8)	(2.4)
Commercial Heating and Cooling | Operating Segments
Segment Reporting Information [Line Items]
Total income from equity method investments	$ 0.2	$ (0.4)	$ 0.2	$ (0.8)