Reportable Business Segments (Key Financial Information by Segment) (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2026	Mar. 31, 2025
Segment Reporting Information [Line Items]
Net sales	$ 1,135.1	$ 1,072.6
Cost of Goods Sold	783.8	731.7
Selling, general and administrative	185.2	171.3
Operating Segments
Segment Reporting Information [Line Items]
Net sales	1,135.1	1,072.6
Cost of Goods Sold	784.0	731.9
Selling, general and administrative	171.2	158.8
Other (income) expense	(2.2)	(0.8)
Segment Profit And Loss	182.1	182.7
Corporate and Other
Segment Reporting Information [Line Items]
Segment Profit And Loss	(18.6)	(14.7)
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Net sales	650.0	721.4
Residential Heating and Cooling [Member] | Operating Segments
Segment Reporting Information [Line Items]
Net sales	650.0	721.4
Cost of Goods Sold	467.8	500.1
Selling, general and administrative	97.2	98.4
Other (income) expense	(1.5)	(1.0)
Segment Profit And Loss	86.5	123.9
Commercial Heating and Cooling
Segment Reporting Information [Line Items]
Net sales	485.1	351.2
Commercial Heating and Cooling | Operating Segments
Segment Reporting Information [Line Items]
Net sales	485.1	351.2
Cost of Goods Sold	316.2	231.8
Selling, general and administrative	74.0	60.4
Other (income) expense	(0.7)	0.2
Segment Profit And Loss	$ 95.6	$ 58.8