Lines of Credit and Financing Arrangements (Outstanding Debt Obligations) (Details) - USD ($) $ in Millions	Mar. 31, 2018	Dec. 31, 2017
Short-Term Debt:
Total short-term debt	$ 0.9	$ 0.9
Current maturities of long-term debt:
Capital lease obligations	0.5	3.2
Debt issuance costs	(0.6)	(0.6)
Total current maturities of long-term debt	29.9	32.6
Long-Term Debt:
Capital lease obligations	11.9	11.9
Debt issuance costs	(4.1)	(4.4)
Total long-term debt	1,258.3	970.5
Total debt	1,289.1	1,004.0
Domestic Credit Facility [Member]
Current maturities of long-term debt:
Domestic credit facility and senior unsecured notes	30.0	30.0
Long-Term Debt:
Domestic credit facility and senior unsecured notes	675.5	337.0
Asset Securitization [Member]
Long-Term Debt:
Domestic credit facility and senior unsecured notes	225.0	276.0
Senior Unsecured Notes [Member]
Long-Term Debt:
Domestic credit facility and senior unsecured notes	350.0	350.0
Foreign Obligations [Member]
Short-Term Debt:
Total short-term debt	$ 0.9	$ 0.9