Accounts and Notes Receivable and Credit Quality of Notes Receivable - Concentration Risk (Details) (Geographic concentration risk, Notes receivable)	9 Months Ended
	Sep. 30, 2014
Peru
Concentration Risk [Line Items]
Concentration risk percentage	25.00%
Mexico
Concentration Risk [Line Items]
Concentration risk percentage	17.00%
Argentina
Concentration Risk [Line Items]
Concentration risk percentage	12.00%
Colombia
Concentration Risk [Line Items]
Concentration risk percentage	10.00%
Other (less than 5% individually)
Concentration Risk [Line Items]
Concentration risk percentage	11.00%
Total international notes receivable as a percentage of total notes receivable
Concentration Risk [Line Items]
Concentration risk percentage	75.00%