Accounts and Notes Receivable and Credit Quality of Notes Receivable (Evaluation of Notes Receivable For Impairment) (Details) - Notes receivable - USD ($) $ in Millions	Jun. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	$ 238.0	$ 282.1
Ending Balance Individually Evaluated for Impairment	139.9	157.1
Ending Balance Collectively Evaluated for Impairment	98.1	125.0
Domestic
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	80.9	95.3
Ending Balance Individually Evaluated for Impairment	39.0	36.1
Ending Balance Collectively Evaluated for Impairment	41.9	59.2
International
Financing Receivable, Recorded Investment, Past Due [Line Items]
Notes receivable	157.1	186.8
Ending Balance Individually Evaluated for Impairment	100.9	121.0
Ending Balance Collectively Evaluated for Impairment	$ 56.2	$ 65.8