Fair Value Measures FV of Partnership's Derivative Assets And Liabilities (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2013	Dec. 31, 2012
Fair Value Measurement, Assets	$ 7	$ 5
Fair Value Measurement, Liabilities	28	31
Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	7	5
Fair Value Measurement, Liabilities	5	6
Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	23	25
Natural Gas Transportation
Fair Value Measurement, Assets	6	2
Fair Value Measurement, Liabilities	1	5
Natural Gas Transportation \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	6	2
Fair Value Measurement, Liabilities	1	5
Natural Gas Transportation \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	0	0
NGLs
Fair Value Measurement, Assets	1	1
Fair Value Measurement, Liabilities	2	1
NGLs \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	1	1
Fair Value Measurement, Liabilities	2	1
NGLs \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	0	0
Condensate
Fair Value Measurement, Assets	0	2
Fair Value Measurement, Liabilities	2	0
Condensate \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	0	2
Fair Value Measurement, Liabilities	2	0
Condensate \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	0	0
Embedded Derivatives in Series A Preferred Units [Member]
Embedded Derivatives in Series A Preferred Units	23	25
Embedded Derivatives in Series A Preferred Units [Member] \| Significant Observable Inputs (Level 2)
Embedded Derivatives in Series A Preferred Units	0	0
Embedded Derivatives in Series A Preferred Units [Member] \| Unobservable Inputs (Level 3)
Embedded Derivatives in Series A Preferred Units	$ 23	$ 25

Fair value of derivative asset, presented on a gross basis even when the derivative instrument is subject to master netting arrangements and qualifies for net presentation in the statement of financial position.

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Derivative instrument obligations meeting the definition of a liability which the Company is a party to as of the balance sheet date.

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- Definition

Fair value as of the balance sheet date of the embedded derivative or group of embedded derivatives classified as a liability.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 12-16, 44A, 44B

-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.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A

-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.

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44A, 44B

-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.

Reference 4: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 133

-Paragraph 44B

-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.

Reference 5: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 815

-SubTopic 10

-Section 50

-Paragraph 4B

-Subparagraph (c)

-URI http://asc.fasb.org/extlink&oid=7476318&loc=SL5624163-113959

+ Details