Partnership's Derivative Assets And Liabilities Measured At Fair Value On A Recurring Basis (Details) (USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Dec. 31, 2011
Fair Value Measurement, Assets	$ 5	$ 4
Transfers Between Level 2 Level 3 Derivatives Amount	0
Fair Value, Measurements, Recurring
Fair Value Measurement, Assets	5	4
Fair Value Measurement, Liabilities	31	50
Embedded Derivatives in Series A Preferred Units	25	39
Fair Value, Measurements, Recurring \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	5	4
Fair Value Measurement, Liabilities	6	11
Embedded Derivatives in Series A Preferred Units	0	0
Fair Value, Measurements, Recurring \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	25	39
Embedded Derivatives in Series A Preferred Units	25	39
Fair Value, Measurements, Recurring \| Natural Gas
Fair Value Measurement, Assets	2	4
Fair Value Measurement, Liabilities	5	0
Fair Value, Measurements, Recurring \| Natural Gas \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	2	4
Fair Value Measurement, Liabilities	5	0
Fair Value, Measurements, Recurring \| Natural Gas \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	0	0
Fair Value, Measurements, Recurring \| NGLs
Fair Value Measurement, Assets	1	0
Fair Value Measurement, Liabilities	1	9
Fair Value, Measurements, Recurring \| NGLs \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	1	0
Fair Value Measurement, Liabilities	1	9
Fair Value, Measurements, Recurring \| NGLs \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	0	0
Fair Value, Measurements, Recurring \| Condensate
Fair Value Measurement, Assets	2	0
Fair Value Measurement, Liabilities	0	2
Fair Value, Measurements, Recurring \| Condensate \| Significant Observable Inputs (Level 2)
Fair Value Measurement, Assets	2	0
Fair Value Measurement, Liabilities	0	2
Fair Value, Measurements, Recurring \| Condensate \| Unobservable Inputs (Level 3)
Fair Value Measurement, Assets	0	0
Fair Value Measurement, Liabilities	$ 0	$ 0

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.

+ References+ Details

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

+ References+ Details

- 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