Reportable Business Segments (Depreciation and Amortization Expense by Segment) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 86.0	$ 77.9	$ 72.4
Residential Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	35.3	31.5	27.6
Commercial Heating and Cooling [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	19.4	17.9	17.4
Corporate and Other [Member]
Segment Reporting Information [Line Items]
Total depreciation and amortization	$ 31.3	$ 28.5	$ 27.4