Fair Value of Financial Instruments #2 (Details) (USD $)	3 Months Ended
Mar. 31, 2013	Dec. 31, 2012
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Transfers of financial instruments, Level 1, assets, net	$ 0
Transfers of financial instruments, Level 1, liabilities, net	0
Transfers of financial instruments, Level 2, assets, net	0
Transfers of financial instruments, Level 2, liabilities, net	0
Transfers of financial instruments, Level 3, assets, net	0
Transfers of financial instruments, Level 3, liabilities, net	0
Marketable Securities, Noncurrent	271,000,000	261,000,000
Investments in Marketable Securities [Abstract]
Notional values for derivative portfolio	178,000,000	164,000,000
Cash Flow Hedging [Member]
Investments in Marketable Securities [Abstract]
Notional values for derivative portfolio	$ 98,000,000	$ 110,000,000

Fair Value, Measurement with Level 1 Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net

No definition available.

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- Definition

Fair Value, Measurement with Level 1 Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net

+ References

No definition available.

+ Details

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- Definition

Fair Value, Measurement with Level 2 Inputs Reconciliation, Recurring Basis, Asset, Transfers, Net

+ References

No definition available.

+ Details

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- Definition

Fair Value, Measurement with Level 2 Inputs Reconciliation, Recurring Basis, Liability, Transfers, Net

+ References

No definition available.

+ Details

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- Definition

This element represents [net] transfers in to and out of assets measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 157

-Paragraph 32

-Subparagraph c(3)

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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- Definition

This element represents [net] transfers in to and out of liabilities measured at fair value on a recurring basis using unobservable inputs (Level 3) which have taken place during the period.

+ References

No definition available.

+ Details

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- Definition

Total debt and equity financial instruments including: (1) securities held-to-maturity and (2) securities available-for-sale that will be held for the long-term.

+ 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 210.5-02.12)

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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 320

-SubTopic 10

-Section 45

-Paragraph 2

-URI http://asc.fasb.org/extlink&oid=6871852&loc=d3e26626-111562

Reference 3: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 115

-Paragraph 17

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

+ Details

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- Definition

Aggregate notional amount of foreign currency exchange rate derivatives. Notional amount refers to the number of currency units specified in the foreign currency derivative contract.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Notional Amount

-URI http://asc.fasb.org/extlink&oid=6519104

+ Details

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