TRANSACTIONS WITH MAJOR CUSTOMERS (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
Transactions with major customers
Revenues	$ 85	$ 84	$ 253	$ 256
Total revenues \| Customer concentration risk \| Anadarko Energy Services Company
Transactions with major customers
Revenues	12	12	36	36
Total revenues \| Customer concentration risk \| Pacific Gas and Electric Company
Transactions with major customers
Revenues	$ 11	$ 12	$ 35	$ 35

Revenue derived from the regulated (by a federal, state, or local government or agency) generation, transmission and distribution of [natural] gas.

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(b))

-URI http://asc.fasb.org/extlink&oid=6880815&loc=d3e20235-122688

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