Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($)	Sep. 30, 2020	Dec. 31, 2019	Nov. 01, 2016
Current maturities of long-term debt:
Finance lease obligations	$ 9,600,000	$ 7,800,000
Debt issuance costs	(2,600,000)	(900,000)
Total current maturities of long-term debt	7,000,000.0	321,900,000
Long-Term Debt:
Finance lease obligations	28,800,000	25,900,000
Debt issuance costs	(6,700,000)	(2,100,000)
Total long-term debt	1,006,600,000	849,300,000
Total debt	1,013,600,000	1,171,200,000
Domestic Credit Facility [Member]
Current maturities of long-term debt:
Domestic credit facility and senior unsecured notes	0	30,000,000.0
Long-Term Debt:
Domestic credit facility and senior unsecured notes	34,500,000	475,500,000
Asset Securitization [Member]
Current maturities of long-term debt:
Domestic credit facility and senior unsecured notes	0	285,000,000.0
Senior Unsecured Notes [Member]
Long-Term Debt:
Domestic credit facility and senior unsecured notes	950,000,000.0	350,000,000.0
Debt Instrument, Interest Rate, Stated Percentage			3.00%
Foreign Obligations [Member]
Long-Term Debt:
Short-term Debt	$ 0	$ 0

Amount of capital lease obligation due within one year or the normal operating cycle, if longer.

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