Segment Information Operating Results for Each Segment (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014
External Revenues	$ 999us-gaap_Revenues	$ 863us-gaap_Revenues
Intersegment Revenue	0rgp_IntersegmentRevenue	0rgp_IntersegmentRevenue
Segment Margin	358rgp_SegmentMargin	225rgp_SegmentMargin
Operation and maintenance	133us-gaap_OperatingCostsAndExpenses	78us-gaap_OperatingCostsAndExpenses
Gathering and Processing
External Revenues	887	793
Intersegment Revenue	0	0
Segment Margin	261	166
Operation and maintenance	107	60
Natural Gas Transportation
External Revenues	0	0
Intersegment Revenue	0	0
Segment Margin	0	0
Operation and maintenance	0	0
NGL Services
External Revenues	0	0
Intersegment Revenue	0	0
Segment Margin	0	0
Operation and maintenance	0	0
Contract Services
External Revenues	84	63
Intersegment Revenue	1	4
Segment Margin	70	56
Operation and maintenance	22	20
Natural Resources
External Revenues	25	2
Intersegment Revenue	0	0
Segment Margin	25	2
Operation and maintenance	4	0
Corporate
External Revenues	3	5
Intersegment Revenue	0	0
Segment Margin	3	5
Operation and maintenance	1	2
Eliminations
External Revenues	0	0
Intersegment Revenue	(1)	(4)
Segment Margin	(1)	(4)
Operation and maintenance	$ (1)	$ (4)

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

No definition available.

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- Definition

Total revenues less cost of good sold for each reporting segment

+ References

No definition available.

+ Details

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- 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

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- Definition

Amount of revenue recognized from goods sold, services rendered, insurance premiums, or other activities that constitute an earning process. Includes, but is not limited to, investment and interest income before deduction of interest expense when recognized as a component of revenue, and sales and trading gain (loss).

+ References

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

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1)

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

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

-Publisher SEC

-Name Regulation S-X (SX)

-Number 210

-Section 03

-Paragraph 1

-Article 5

+ Details

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- Details

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- Details

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- Details

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- Details

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