Accounts and Other Receivables (Allowance For Doubtful Accounts) (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	$ 20.2	$ 4.9
Add: Charges	2.8	16.7	$ 0.8
Less: Net Charge-offs/(Recoveries) and Other	(0.5)	1.4
Ending Balance	23.5	20.2	4.9
Total trade receivables
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5.2	4.9
Add: Charges	2.8	1.7
Less: Net Charge-offs/(Recoveries) and Other	(0.5)	1.4
Ending Balance	8.5	5.2	4.9
Trade accounts receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	5.2	4.7
Add: Charges	2.7	1.9
Less: Net Charge-offs/(Recoveries) and Other	(0.5)	1.4
Ending Balance	8.4	5.2	4.7
Trade notes receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	0.0	0.2
Add: Charges	0.1	(0.2)
Less: Net Charge-offs/(Recoveries) and Other	0.0	0.0
Ending Balance	0.1	0.0	0.2
Other notes receivable
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Beginning Balance	15.0	0.0
Add: Charges	0.0	15.0
Less: Net Charge-offs/(Recoveries) and Other	0.0	0.0
Ending Balance	$ 15.0	$ 15.0	$ 0.0