v2.4.1.9

Derivative Instruments and Hedging Activities Additional Information (Details) (Commodity contracts, Not Designated as Hedging Instrument, USD $) In Thousands, unless otherwise specified	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014
Commodity contracts | Not Designated as Hedging Instrument
Derivative [Line Items]
Gain (loss) on sale of derivatives	$ (1,053)us-gaap_GainLossOnSaleOfDerivatives / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_HedgingDesignationAxis = us-gaap_NondesignatedMember	$ (17)us-gaap_GainLossOnSaleOfDerivatives / us-gaap_DerivativeInstrumentRiskAxis = us-gaap_CommodityContractMember / us-gaap_HedgingDesignationAxis = us-gaap_NondesignatedMember

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- Details

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X

- Definition

The difference between the book value and the sale price of options, swaps, futures, forward contracts, and other derivative instruments. This element refers to the gain (loss) included in earnings.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 230

-SubTopic 10

-Section 45

-Paragraph 28

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=31042434&loc=d3e3602-108585



Reference 2: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 942

-SubTopic 225

-Section S99

-Paragraph 1

-Subparagraph (SX 210.9-04.13(h))

-URI http://asc.fasb.org/extlink&oid=6879574&loc=d3e536633-122882

+ Details

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration