Financial Instruments - Narrative (Details) - Not Designated as Hedging Instrument	9 Months Ended
	Sep. 30, 2015	Sep. 30, 2014
Minimum | Foreign currency forward contracts
Derivative [Line Items]
Derivative contract term (months)	1 month	1 month
Minimum | Cross-currency option
Derivative [Line Items]
Derivative contract term (months)	1 month	1 month
Maximum | Foreign currency forward contracts
Derivative [Line Items]
Derivative contract term (months)	3 months	3 months
Maximum | Cross-currency option
Derivative [Line Items]
Derivative contract term (months)	3 months	3 months