Derivative Financial Instruments - Schedule of outstanding commodity and currency forward contracts (Details)	12 Months Ended
	Dec. 31, 2015 USD ($) MMBTU T t	Dec. 31, 2014 USD ($) MMBTU T t	Dec. 31, 2015 GBP (£)	Dec. 31, 2015 KRW (₩)	Dec. 31, 2015 MXN	Dec. 31, 2015 SGD	Dec. 31, 2015 CAD	Dec. 31, 2015 EUR (€)	Dec. 31, 2015 JPY (¥)	Dec. 31, 2015 AUD	Dec. 31, 2014 KRW (₩)	Dec. 31, 2014 MXN	Dec. 31, 2014 SGD	Dec. 31, 2014 CAD	Dec. 31, 2014 EUR (€)	Dec. 31, 2014 AUD
Commodity contracts | Designated as Hedging Instrument | Aluminum
Derivative [Line Items]
Commodity units hedged, mass	1,040	1,657
Commodity contracts | Designated as Hedging Instrument | Copper
Derivative [Line Items]
Commodity units hedged, mass	472	820
Commodity contracts | Designated as Hedging Instrument | Natural Gas
Derivative [Line Items]
Commodity units hedged, energy | MMBTU	291,260	347,608
Commodity contracts | Designated as Hedging Instrument | Steel
Derivative [Line Items]
Commodity units hedged, mass | T	11,895	14,665
Commodity contracts | Not Designated as Hedging Instrument | Aluminum
Derivative [Line Items]
Commodity units hedged, mass	175
Commodity contracts | Not Designated as Hedging Instrument | Steel
Derivative [Line Items]
Commodity units hedged, mass | T	3,989
Foreign currency exchange contracts | Designated as Hedging Instrument | Canadian Dollar
Derivative [Line Items]
Currency units hedged | CAD							CAD 587,556							CAD 7,984,824
Foreign currency exchange contracts | Designated as Hedging Instrument | European Euro
Derivative [Line Items]
Currency units hedged | €								€ 231,810							€ 89,006,695
Foreign currency exchange contracts | Designated as Hedging Instrument | South Korean Won
Derivative [Line Items]
Currency units hedged | ₩				₩ 1,533,257,930							₩ 1,964,906,996
Foreign currency exchange contracts | Designated as Hedging Instrument | Singapore Dollar
Derivative [Line Items]
Currency units hedged | SGD						SGD 1,800,000							SGD 3,900,000
Foreign currency exchange contracts | Designated as Hedging Instrument | United States Dollar
Derivative [Line Items]
Currency units hedged | $		$ 29,228,731
Foreign currency exchange contracts | Designated as Hedging Instrument | Mexican Peso
Derivative [Line Items]
Currency units hedged | MXN					MXN 28,504,800							MXN 52,674,387
Foreign currency exchange contracts | Designated as Hedging Instrument | Japanese Yen
Derivative [Line Items]
Currency units hedged | ¥									¥ 245,915,700
Foreign currency exchange contracts | Designated as Hedging Instrument | Great British Pound
Derivative [Line Items]
Currency units hedged | £			£ 113,115
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Canadian Dollar
Derivative [Line Items]
Currency units hedged | CAD							CAD 1,117,850							CAD 2,516
Foreign currency exchange contracts | Not Designated as Hedging Instrument | European Euro
Derivative [Line Items]
Currency units hedged | €								€ 20,490,320							€ 73,302,332
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Singapore Dollar
Derivative [Line Items]
Currency units hedged | SGD						SGD 500,000
Foreign currency exchange contracts | Not Designated as Hedging Instrument | United States Dollar
Derivative [Line Items]
Currency units hedged | $	$ 17,321,106	$ 18,244,912
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Mexican Peso
Derivative [Line Items]
Currency units hedged | MXN					MXN 0							MXN 3,151,000
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Japanese Yen
Derivative [Line Items]
Currency units hedged | ¥									¥ 70,518,463
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Great British Pound
Derivative [Line Items]
Currency units hedged | £			£ 4,840,238
Foreign currency exchange contracts | Not Designated as Hedging Instrument | Australian Dollar
Derivative [Line Items]
Currency units hedged | AUD										AUD 0						AUD 2,482,430