Derivative Instruments and Hedging Activities - OCI (Details) - USD ($) $ in Thousands	3 Months Ended
Mar. 31, 2018	Mar. 31, 2017
Effect of derivative instruments on earnings
Gain (Loss) Recognized in OCI	$ (1,472)	$ (550)
Reclassified from Accumulated OCI into Earnings
Effect of derivative instruments on earnings
Gain (Loss) Reclassified from Accumulated OCI into Earnings	(287)	1,122
Foreign currency forward contracts
Effect of derivative instruments on earnings
Gain (Loss) Recognized in OCI	(11)	23
Foreign currency forward contracts \| Reclassified from Accumulated OCI into Earnings
Effect of derivative instruments on earnings
Gain (Loss) Reclassified from Accumulated OCI into Earnings	47	(25)
Commodity futures contracts
Effect of derivative instruments on earnings
Gain (Loss) Recognized in OCI	(1,461)	(573)
Commodity futures contracts \| Reclassified from Accumulated OCI into Earnings
Effect of derivative instruments on earnings
Gain (Loss) Reclassified from Accumulated OCI into Earnings	$ (334)	$ 1,147

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- Definition

The effective portion of net gain (loss) reclassified from accumulated other comprehensive income into income on derivative instruments designated and qualifying as hedging instruments.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4C
-Subparagraph (c)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624171-113959

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 815
-SubTopic 10
-Section 50
-Paragraph 4D
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=84234895&loc=SL5624177-113959

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- Definition

The effective portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments that was recognized in other comprehensive income during the current period.

+ References

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