DERIVATIVE FINANCIAL INSTRUMENTS (Details) (USD $) In Millions, unless otherwise specified	Jun. 30, 2012		Mar. 31, 2012
S D G E Segment [Member]
Schedule Of Commodity Derivative Volumes [Line Items]
Commodity derivative volumes, natural gas (in millions of million British thermal units)	$ 29	[1]	$ 35	[1]
Commodity derivative volumes, congestion revenue rights (in millions of megawatt hours)	14	[2]	19	[2]
Sempra Mexico Segment [Member]
Schedule Of Commodity Derivative Volumes [Line Items]
Commodity derivative volumes, natural gas (in millions of million British thermal units)	1	[1]	1	[1]
Sempra Natural Gas Segment [Member]
Schedule Of Commodity Derivative Volumes [Line Items]
Commodity derivative volumes, natural gas (in millions of million British thermal units)	21	[1]	20	[1]
Commodity derivative volumes, electric power (in millions of megawatt hours)	$ 4	[2]	$ 5	[2]

[1] Million British thermal units

[2] Megawatt hours