Fair Value Measurements (Details) (Fair value, measurements, recurring, USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total assets at fair value	$ 45,123us-gaap_AssetsFairValueDisclosure	$ 41,797us-gaap_AssetsFairValueDisclosure
Commodity contracts, net	(3,925)us-gaap_LiabilitiesFairValueDisclosure
Foreign exchange contracts, net	(53)	(2,570)
Total liabilities at fair value	(49,101)	(48,976)
Commodity contracts
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Commodity contracts, net		(4,609)
Level 1
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total assets at fair value	45,123	41,797
Total liabilities at fair value	(45,123)	(41,797)
Level 2
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Total assets at fair value	0	0
Commodity contracts, net	(3,925)
Foreign exchange contracts, net	(53)	(2,570)
Total liabilities at fair value	(3,978)	(7,179)
Level 2 \| Commodity contracts
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Commodity contracts, net		(4,609)
Supplemental Employee Retirement Plans, Defined Benefit
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Non-qualified deferred compensation assets	45,123	41,797
Non-qualified deferred compensation liabilities	(45,123)	(41,797)
Supplemental Employee Retirement Plans, Defined Benefit \| Level 1
Fair Value, Assets, Liabilities and Stockholders' Equity Measured on Recurring Basis [Abstract]
Non-qualified deferred compensation assets	45,123	41,797
Non-qualified deferred compensation liabilities	$ (45,123)	$ (41,797)

Fair value portion of probable future economic benefits obtained or controlled by an entity as a result of past transactions or events.

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 820

-SubTopic 10

-Section 50

-Paragraph 2

-Subparagraph (a)

-URI http://asc.fasb.org/extlink&oid=36462937&loc=d3e19207-110258

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- Definition

Aggregate carrying value as of the balance sheet date of the liabilities for all deferred compensation arrangements. Represents currently earned compensation under compensation arrangements that is not actually paid until a later date.

+ References

No definition available.

+ Details

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Period Type:	instant

- Definition

Carrying amount as of the balance sheet date of assets held under deferred compensation agreements.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 210

-SubTopic 10

-Section S99

-Paragraph 1

-Subparagraph (SX 210.5-02.17)

-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 02

-Paragraph 17

-Article 5

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- Definition

Fair value portion of liability contracts related to the exchange of different currencies, including, but not limited to, foreign currency options, forward (delivery or nondelivery) contracts, and swaps entered into.

+ References

No definition available.

+ Details

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- Definition

Fair value of financial and nonfinancial obligations.

+ References

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- Definition

Aggregation of the liabilities reported on the balance sheet measured at fair value on a recurring basis by the entity.

+ References

No definition available.

+ Details

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