Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($) $ in Millions	Dec. 31, 2025	Dec. 31, 2024
Debt Instrument [Line Items]
Commercial paper	$ 226.0	$ 0.0
Current maturities of long-term debt:
Finance lease obligations	18.3	14.9
Senior unsecured notes	18.3	314.5
Long-Term Debt:
Finance lease obligations	50.6	39.5
Total long-term debt	1,144.1	833.1
Debt Issuance Cost, Gross, Noncurrent	(6.5)	(6.4)
Total debt	1,388.4	1,147.6
Domestic Credit Facility [Member]
Current maturities of long-term debt:
Debt issuance costs	0.0	(0.4)
Senior unsecured notes	0.0	300.0
Long-Term Debt:
Total long-term debt	300.0	0.0
Senior Unsecured Notes [Member]
Long-Term Debt:
Total long-term debt	$ 800.0	$ 800.0