Accounts and Other Receivables (Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	$ 4.9	$ 7.4
Add: Charges	(16.7)	(0.8)	$ (1.6)
Less: Net Charge-offs, (Recoveries)	1.4	3.3
Ending Balance	20.2	4.9	7.4
Total trade receivables
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	4.9	7.4
Add: Charges	(1.7)	(0.8)
Less: Net Charge-offs, (Recoveries)	1.4	3.3
Ending Balance	5.2	4.9	7.4
Trade accounts receivable
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	4.7	7.1
Add: Charges	(1.9)	(0.9)
Less: Net Charge-offs, (Recoveries)	1.4	3.3
Ending Balance	5.2	4.7	7.1
Trade notes receivable
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	0.2	0.3
Add: Charges	0.2	0.1
Less: Net Charge-offs, (Recoveries)	0.0	0.0
Ending Balance	0.0	0.2	0.3
Other notes receivable
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	0.0	0.0
Add: Charges	(15.0)	0.0
Less: Net Charge-offs, (Recoveries)	0.0	0.0
Ending Balance	$ 15.0	$ 0.0	$ 0.0