v2.4.0.8

Risk Management Effect of Derivative Contracts on the Income Statement (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013
Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)recognized in OCI on derivative(effective portion)	$ (45)	$ (31)
Interest Rate Swap [Member] | Interest expense [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss) recognized in income on derivative	55	(88)
Interest Rate Swap [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)recognized in OCI on derivative(effective portion)	(2)	1
Commodity Contract [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Loss to be reclassified within twelve months	15
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	0	3
Commodity Contract [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)reclassified fromAccumulated OCIinto income(effective portion)	(14)	6
Amount of gain/(loss)recognized in incomeon derivative(ineffective portionand amountexcluded fromeffectiveness testing)	(5)	(3)
Commodity Contract [Member] | Interest expense [Member] | Fair Value Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss) recognized in income on derivative	(55)	88
Commodity Contract [Member] | Interest expense [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)reclassified fromAccumulated OCIinto income(effective portion)	0	1
Amount of gain/(loss)recognized in incomeon derivative(ineffective portionand amountexcluded fromeffectiveness testing)	0	0
Commodity Contract [Member] | Revenues Natural Gas Sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(7)	1
Commodity Contract [Member] | Revenues Natural Gas Sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)reclassified fromAccumulated OCIinto income(effective portion)	(9)	0
Amount of gain/(loss)recognized in incomeon derivative(ineffective portionand amountexcluded fromeffectiveness testing)	0	0
Commodity Contract [Member] | Revenues-Product sales and other [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(1)	2
Commodity Contract [Member] | Revenues-Product sales and other [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)reclassified fromAccumulated OCIinto income(effective portion)	(6)	5
Amount of gain/(loss)recognized in incomeon derivative(ineffective portionand amountexcluded fromeffectiveness testing)	(5)	(3)
Commodity Contract [Member] | Gas purchases and other costs of sales [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	10	0
Commodity Contract [Member] | Gas purchases and other costs of sales [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)reclassified fromAccumulated OCIinto income(effective portion)	1	0
Amount of gain/(loss)recognized in incomeon derivative(ineffective portionand amountexcluded fromeffectiveness testing)	0	0
Commodity Contract [Member] | Other Income (Expense) [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Derivative Instruments Not Designated as Hedging Instruments, Gain (Loss), Net	(2)	0
Commodity Contract [Member] | Other Comprehensive Income (Loss) [Member] | Cash Flow Hedging [Member]
Derivative Instruments, Gain (Loss) [Line Items]
Amount of gain/(loss)recognized in OCI on derivative(effective portion)	$ (43)	$ (32)

X

- Definition

The estimated net amount of existing gains or losses on cash flow hedges at the reporting date expected to be reclassified to earnings within the next 12 months.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 30

-Section 50

-Paragraph 1

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7668309&loc=d3e80748-113994

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- Definition

Amount of increase (decrease) in the fair value of derivatives recognized in the income statement.

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4A

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5618551-113959



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (a),(c),(d),(e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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X

- 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=7476318&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=7476318&loc=SL5624177-113959

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- Definition

The portion of gains and losses (net) on derivative instruments designated and qualifying as hedging instruments representing (a) the amount of the hedge ineffectiveness and (b) the amount, if any, excluded from the assessment of hedge effectiveness.

+ 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 (d)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959



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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 25

-Section 50

-Paragraph 1

-Subparagraph (a)(1),(2)

-URI http://asc.fasb.org/extlink&oid=6886632&loc=d3e76258-113986

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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

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4C

-Subparagraph (b)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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- Definition

Amount of realized and unrealized gain (loss) of derivative instruments not designated or 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 (e)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624171-113959

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