Financing Arrangements - Customer Financing Arrangements (Details) - USD ($) $ in Millions	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Sale of receivable	$ 35.8	$ 25.4
Proceeds from sale and collection of receivables	33.0	$ 23.1
Receivables from sale of receivables	$ 16.5		$ 13.7
Minimum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of days due from receivable	1 day
Maximum
Accounts, Notes, Loans and Financing Receivable [Line Items]
Number of days due from receivable	90 days