Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($)	Dec. 31, 2018	Dec. 31, 2017	Nov. 01, 2016
Short-Term Debt:
Total short-term debt	$ 0	$ 900,000
Current maturities of long-term debt:
Capital lease obligations	3,500,000	3,200,000
Domestic credit facility	300,800,000	32,600,000
Long-Term Debt:
Capital lease obligations	15,700,000	11,900,000
Total long-term debt	740,500,000	970,500,000
Debt Issuance Cost, Gross, Noncurrent	(3,200,000)	(4,400,000)
Total debt	1,041,300,000	1,004,000,000
Domestic Credit Facility [Member]
Current maturities of long-term debt:
Domestic credit facility	30,000,000	30,000,000
Debt Issuance Costs, Gross, Current	(700,000)	(600,000)
Long-Term Debt:
Total long-term debt	378,000,000	337,000,000
Asset Securitization [Member]
Current maturities of long-term debt:
Capital lease obligations	268,000,000	0
Long-Term Debt:
Total long-term debt	0	276,000,000
Senior Unsecured Notes [Member]
Debt Instrument [Line Items]
Debt instrument, face amount			$ 350,000,000
Long-Term Debt:
Total long-term debt	350,000,000	350,000,000
Foreign Obligations [Member]
Short-Term Debt:
Total short-term debt	$ 0	$ 900,000