Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($)	Jun. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Commercial paper	$ 147,000,000.0	$ 150,000,000.0
Current maturities of long-term debt:
Finance lease obligations	14,000,000.0	12,100,000
Total current maturities of long-term debt	14,000,000.0	12,100,000
Long-Term Debt:
Finance lease obligations	35,000,000.0	32,700,000
Debt issuance costs	(8,200,000)	(9,600,000)
Total long-term debt	1,126,800,000	1,143,100,000
Total debt	1,287,800,000	1,305,200,000
Senior Unsecured Notes
Long-Term Debt:
Domestic credit facility and senior unsecured notes	1,100,000,000	1,100,000,000
Domestic Credit Facility
Long-Term Debt:
Domestic credit facility and senior unsecured notes	0	20,000,000.0
Foreign Obligations
Long-Term Debt:
Short-term Debt	$ 0	$ 0