Accounts and Notes Receivable and Credit Quality of Notes Receivable - Evaluation of Notes Receivable For Impairment (Details) (Notes receivable, USD $) In Millions, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	$ 191.0	$ 236.9
Ending balance individually evaluated for impairment	85.6	104.5
Ending balance collectively evaluated for impairment	105.4	132.4
Domestic
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	48.1	65.1
Ending balance individually evaluated for impairment	6.7	4.8
Ending balance collectively evaluated for impairment	41.4	60.3
International
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	142.9	171.8
Ending balance individually evaluated for impairment	78.9	99.7
Ending balance collectively evaluated for impairment	$ 64.0	$ 72.1