Accounts and Notes Receivable and Credit Quality of Notes Receivable (Allowance for Doubtful Accounts Receivable) (Details) - Notes receivable - USD ($) $ in Millions	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Financing Receivable, Allowance for Credit Losses [Roll Forward]
Beginning balance	$ 5.9	$ 5.6
Charge-offs	(1.9)	(0.1)
Recoveries	(0.5)	0.0
Provision	7.9	1.9
Ending balance	11.4	7.4
Financing Receivable, Allowance for Credit Losses, Individually Evaluated for Impairment [Roll Forward]
Beginning balance	5.9	5.6
Charge-offs	(1.9)	(0.1)
Recoveries	(0.4)	0.0
Provision	6.2	1.9
Ending balance	9.8	7.4
Financing Receivable, Allowance for Credit Losses, Collectively Evaluated for Impairment [Roll Forward]
Beginning balance	0.0	0.0
Charge-offs	0.0	0.0
Recoveries	(0.1)	0.0
Provision	1.7	0.0
Ending balance	$ 1.6	$ 0.0