Accounts Receivable Sale Program (Narrative) (Details) $ in Millions	12 Months Ended
	Dec. 31, 2017 USD ($)
Receivables [Abstract]
Maximum Limit Accounts Receivable Sale Program	$ 40.0
Trade Accounts Receivable Sold	145.0
Amount Received From Trade Accounts Receivable Sold To Third Party	144.7
Loss on sale of accounts receivable resulting from discount	$ 0.3