INVESTMENTS IN UNCONSOLIDATED ENTITIES (Details) (USD $) In Millions, unless otherwise specified	3 Months Ended
	Mar. 31, 2011	Mar. 31, 2012
Investment In Joint Venture Disclosure [Abstract]
Investment in RBS Sempra Commodities LLP		$ 126
Pretax equity earnings (losses) from RBS Sempra Commodities LLP	(8)
Schedule of Equity Method Investments [Line Items]
Sempra Renewables' Equity Method Investments In Joint Ventures		50
Rockies Express [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percentage in equity method investee		25.00%
Ownership percentage of minority partner in equity method investee		25.00%
Ownership percentage of operating partner in equity method investee		50.00%
Flat Ridge 2 [Member]
Schedule of Equity Method Investments [Line Items]
Sempra Renewables' Equity Method Investments In Joint Ventures		$ 43