Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($)	Sep. 30, 2024	Dec. 31, 2023
Debt Instrument [Line Items]
Commercial paper	$ 0	$ 150,000,000.0
Current maturities of long-term debt:
Finance lease obligations	13,200,000	12,100,000
Debt issuance costs	(500,000)	0
Total current maturities of long-term debt	312,700,000	12,100,000
Long-Term Debt:
Finance lease obligations	34,600,000	32,700,000
Debt issuance costs	(7,000,000.0)	(9,600,000)
Total long-term debt	827,600,000	1,143,100,000
Total debt	1,140,300,000	1,305,200,000
Senior Unsecured Notes
Current maturities of long-term debt:
Senior unsecured notes	300,000,000.0	0
Long-Term Debt:
Domestic credit facility and senior unsecured notes	800,000,000.0	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