Reportable Business Segments (Key Financial Information by Segment) (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]
Net sales	$ 1,545.3	$ 1,500.9	$ 2,680.4	$ 2,573.5
Cost of goods sold			1,788.7	1,714.2
Selling, general and administrative			334.7	311.3
Other (income) expense			(2.2)	(7.3)
Segment Profit And Loss			559.2	555.3
Operating Segments
Segment Reporting Information [Line Items]
Net sales	1,545.3	1,500.9
Cost of goods sold	1,004.7	982.3
Selling, general and administrative	163.5	152.5
Other (income) expense	0.0	(6.5)
Segment Profit And Loss	377.1	372.6
Corporate and Other
Segment Reporting Information [Line Items]
Segment Profit And Loss	(22.1)	(23.6)	(40.7)	(38.3)
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Net sales	935.6	1,009.3	1,585.6	1,730.7
Residential Heating and Cooling [Member] | Operating Segments
Segment Reporting Information [Line Items]
Net sales	935.6	1,009.3	1,585.6	1,730.7
Cost of goods sold	626.0	671.5	1,093.8	1,171.6
Selling, general and administrative	88.0	91.4	185.2	189.8
Other (income) expense	(0.2)	(5.6)	(1.7)	(6.6)
Segment Profit And Loss	221.8	252.0	308.3	375.9
Commercial Heating and Cooling
Segment Reporting Information [Line Items]
Net sales	609.7	491.6	1,094.8	842.8
Commercial Heating and Cooling | Operating Segments
Segment Reporting Information [Line Items]
Net sales	609.7	491.6	1,094.8	842.8
Cost of goods sold	378.7	310.8	694.9	542.6
Selling, general and administrative	75.5	61.1	149.5	121.5
Other (income) expense	0.2	(0.9)	(0.5)	(0.7)
Segment Profit And Loss	$ 155.3	$ 120.6	$ 250.9	$ 179.4