Segment Information Operating Results for Each Segment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended	9 Months Ended
Sep. 30, 2013	Sep. 30, 2012	Sep. 30, 2013	Sep. 30, 2012
External Revenues	$ 665	$ 527	$ 1,844	$ 1,413
Intersegment Revenues	0	0	0	0
Segment Margin	188	158	535	454
Operation and maintenance	78	61	220	159
Gathering and Processing
External Revenues	603	475	1,671	1,262
Intersegment Revenues	0	0	0	0
Segment Margin	136	110	383	314
Operation and maintenance	63	50	177	125
Natural Gas Transportation
External Revenues	0	0	0	0
Intersegment Revenues	0	0	0	0
Segment Margin	0	0	0	1
Operation and maintenance	0	0	0	0
NGL Services
External Revenues	0	0	0	0
Intersegment Revenues	0	0	0	0
Segment Margin	0	0	0	0
Operation and maintenance	0	0	0	0
Contract Services
External Revenues	58	47	159	137
Intersegment Revenues	4	5	11	15
Segment Margin	52	48	149	140
Operation and maintenance	19	16	53	49
Corporate
External Revenues	4	5	14	14
Intersegment Revenues	0	0	0	0
Segment Margin	4	5	14	14
Operation and maintenance	0	0	1	0
Eliminations
External Revenues	0	0	0	0
Intersegment Revenues	(4)	(5)	(11)	(15)
Segment Margin	(4)	(5)	(11)	(15)
Operation and maintenance	$ (4)	$ (5)	$ (11)	$ (15)

Total revenues less cost of good sold for each reporting segment

No definition available.

Name:	rgp_SegmentMargin
Namespace Prefix:	rgp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Generally recurring costs associated with normal operations except for the portion of these expenses which can be clearly related to production and included in cost of sales or services. Excludes Selling, General and Administrative Expense.

+ References

No definition available.

+ Details

Name:	us-gaap_OperatingCostsAndExpenses
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Amount of revenue from external customers for the reportable segment. Such disclosure is presented if the amount is: (a) included in the measure of segment profit or loss reviewed by the chief operating decision maker or (b) otherwise regularly provided to the chief operating decision maker, even if not included in that measure of segment profit or loss.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph a

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009.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

Name:	us-gaap_RevenuesFromExternalCustomers
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of revenue from transactions with other operating segments of the same entity.

+ References

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

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 131

-Paragraph 27

-Subparagraph b

-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

Name:	us-gaap_RevenuesFromTransactionsWithOtherOperatingSegmentsOfSameEntity
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration