OTHER FINANCIAL DATA - INVENTORY (Details) (USD $) In Millions, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Inventory [Line Items]
Energy Related Inventory, Natural Gas in Storage	$ 93	$ 240
Energy Related Inventory, Liquefied Natural Gas	13	16
Energy Related Inventory, Materials And Supplies	164	152
Inventory, Total	270	408	[1]
S D G E Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Natural Gas in Storage	1	3
Energy Related Inventory, Materials And Supplies	80	79
Inventory, Total	81	82
So Cal Gas Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Natural Gas in Storage	8	128
Energy Related Inventory, Materials And Supplies	26	23
Inventory, Total	34	151
Sempra South American Utilities Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Materials And Supplies	38	34
Inventory, Total	38	34
Sempra Mexico Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Liquefied Natural Gas	7	8
Energy Related Inventory, Materials And Supplies	12	8
Inventory, Total	19	16
Sempra Natural Gas Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Natural Gas in Storage	84	109
Energy Related Inventory, Liquefied Natural Gas	6	8
Energy Related Inventory, Materials And Supplies	5	5
Inventory, Total	95	122
Sempra Renewables Segment [Member]
Inventory [Line Items]
Energy Related Inventory, Materials And Supplies	3	3
Inventory, Total	$ 3	$ 3

[1] Derived from audited financial statements.