CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 1,407	$ 733	$ 1,122
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	978	867	775
Deferred income taxes and investment tax credits	(24)	48	295
Equity earnings	(61)	243	(567)
Remeasurement of equity method investments	(277)
Write-off of long-lived assets			132
Fixed-price contracts and other derivatives	2	13	(30)
Other adjustments to reconcile net income to net cash provided by operating activities	(15)	(55)	(48)
Net change in other working capital components [Abstract]
Net change in accounts and notes receivable	(32)	89	(190)
Net change in income taxes, net	268	(30)	(17)
Net change in inventories	(84)	(62)	124
Net change in regulatory balancing accounts	(150)	(155)	42
Net change in regulatory assets and liabilities	(2)	6	(1)
Net change in other current assets	295	310	685
Net change in accounts payable	60	79	(109)
Net change in other current liabilities	(580)	(179)	(790)
Net change in other working capital components	(225)	58	(256)
Distributions from RBS Sempra Commodities LLP, operating activities	53	198	407
Changes in other assets	34	54	139
Changes in other liabilities	(5)	(5)	(94)
Net cash provided by operating activities	1,867	2,154	1,875
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(2,844)	(2,062)	(1,912)
Proceeds from sale of assets	2	303	179
Expenditures for investments and acquisition of businesses, net of cash acquired	(941)	(611)	(939)
Distributions from RBS Sempra Commodities LLP, investing activities	570	849
Distributions from investments	64	371	23
Purchases of nuclear decommissioning and other trust assets	(755)	(371)	(267)
Proceeds from sales by nuclear decommissioning and other trusts	753	372	230
Decrease (increase) in notes receivable from unconsolidated affiliates, net			100
Purchase of bonds issued by unconsolidated affiliate			(50)
Decrease in restricted cash	653	195	37
Increase in restricted cash	(541)	(318)	(45)
Other cash flows from investing activities	(31)	(11)	(28)
Net cash used in investing activities	(3,070)	(1,283)	(2,672)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(440)	(364)	(341)
Preferred dividends paid by subsidiaries	(8)	(10)	(10)
Issuances of common stock	28	40	73
Repurchases of common stock	(18)	(502)	(22)
Redemption of subsidiary preferred stock	(80)
Issuances of debt (maturities greater than 90 days)	2,098	1,125	2,151
Payments on debt (maturities greater than 90 days)	(482)	(905)	(435)
Increase (decrease) in short-term debt, net	(498)	568	(659)
Payments on notes payable to unconsolidated affiliate			(100)
Purchase of noncontrolling interests	(43)		(94)
Other cash flows from financing activities	(23)	(21)	13
Net cash provided by (used in) financing activities	534	(69)	576
Effect of exchange rate changes on cash and cash equivalents	9
Increase (decrease) in cash and cash equivalents	(660)	802	(221)
Cash and cash equivalents, beginning of period	912	110	331
Cash and cash equivalents, end of period	252	912	110
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	440	415	326
Income tax payments, net of refunds	144	68	112
Acquisition Of Business [Abstract]
Assets acquired	2,833	303
Cash paid, net of cash acquired	(611)	(292)
Fair of equity method investments immediately prior to the acquisition	(882)
Fair value of noncontrolling interests	(279)
Additional consideration accrued	(32)
Liabilities assumed	1,029	11
Increase in capital lease obligations for investments in property, plant and equipment		192	50
Accrued capital expenditures	368	341	247
Return of investment	180
SUPPLEMENTAL DISCLOSURE OF NONCASH FINANCING ACTIVITIES
Dividends declared but not paid	120	96	99
Cancellation of debt	180
Conversion of debt to equity	30
San Diego Gas and Electric Company and Subsidiary [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	455	358	373
Adjustments to reconcile net income to net cash provided by operating activities:
Utility depreciation and amortization	422	381	329
Deferred income taxes and investment tax credits	290	52	73
Fixed-price contracts and other derivatives	(13)	22	(41)
Other adjustments to reconcile net income to net cash provided by operating activities	(68)	(32)	(21)
Net change in other working capital components [Abstract]
Net change in accounts and notes receivable	6		(53)
Net change in due to/from affiliates, net	6	(2)
Net change in income taxes, net	(111)	12	(44)
Net change in inventories	(11)	(10)	1
Net change in regulatory balancing accounts	(87)	(99)	32
Net change in other current assets	309	343	660
Net change in accounts payable	68	23	1
Net change in interest payable	6	10
Net change in other current liabilities	(430)	(340)	(639)
Net change in other working capital components	(244)	(63)	(42)
Changes in other assets	33	14	23
Changes in other liabilities	7	(3)	(53)
Net cash provided by operating activities	882	729	641
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(1,831)	(1,210)	(955)
Proceeds from sale of assets	1		1
Expenditures for short-term investments			(152)
Proceeds from sale of short-term investments			176
Purchases of nuclear decommissioning trust assets	(748)	(362)	(237)
Proceeds from sales by nuclear decommissioning trusts	741	352	230
Decrease (increase) in notes receivable from unconsolidated affiliates, net		14	20
Decrease in restricted cash	520	152	37
Increase in restricted cash	(447)	(260)	(45)
Net cash used in investing activities	(1,764)	(1,314)	(925)
CASH FLOWS FROM FINANCING ACTIVITIES
Capital contribution	200
Common dividends paid			(150)
Preferred dividends paid	(5)	(5)	(5)
Issuances of long-term debt	598	744	439
Payments on long-term debt	(10)	(10)	(2)
Increase (decrease) in short-term debt, net			4
Capital contributions received by variable interest entity	5		4
Capital distributions made by variable interest entity		(24)	(9)
Other cash flows from financing activities	(4)	(6)	(3)
Net cash provided by (used in) financing activities	784	699	278
Increase (decrease) in cash and cash equivalents	(98)	114	(6)
Cash and cash equivalents, beginning of period	127	13	19
Cash and cash equivalents, end of period	29	127	13
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	131	120	99
Income tax payments, net of refunds	59	108	148
Acquisition Of Business [Abstract]
Increase in capital lease obligations for investments in property, plant and equipment		188	21
Accrued capital expenditures	187	173	157
SUPPLEMENTAL DISCLOSURE OF NONCASH FINANCING ACTIVITIES
Dividends declared but not paid	1	1	1
Southern California Gas Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	288	287	274
Adjustments to reconcile net income to net cash provided by operating activities:
Utility depreciation and amortization	331	309	293
Deferred income taxes and investment tax credits	130	107	70
Other adjustments to reconcile net income to net cash provided by operating activities	(6)		8
Net change in other working capital components [Abstract]
Net change in accounts and notes receivable	(57)	18	(30)
Net change in due to/from affiliates, net	(18)	11	(10)
Net change in income taxes, net	(12)	5	(2)
Net change in inventories	(46)	(12)	74
Net change in regulatory balancing accounts	(63)	(56)	10
Net change in other current assets	5	(2)	10
Net change in accounts payable	(7)	52	(99)
Net change in customer deposits	2	(13)	(28)
Net change in other current liabilities	(5)	29	(69)
Net change in other working capital components	(201)	32	(144)
Changes in other assets	19	(7)	7
Changes in other liabilities	(7)	8	(68)
Net cash provided by operating activities	554	736	440
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(683)	(503)	(480)
Decrease (increase) in notes receivable from unconsolidated affiliates, net	49	(63)	(16)
Net cash used in investing activities	(634)	(566)	(496)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(50)	(100)
Preferred dividends paid	(1)	(1)	(1)
Issuances of long-term debt		299
Payments on long-term debt	(250)		(100)
Net cash provided by (used in) financing activities	(301)	198	(101)
Increase (decrease) in cash and cash equivalents	(381)	368	(157)
Cash and cash equivalents, beginning of period	417	49	206
Cash and cash equivalents, end of period	36	417	49
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	65	54	59
Income tax payments, net of refunds	25	64	76
Acquisition Of Business [Abstract]
Increase in capital lease obligations for investments in property, plant and equipment		4	29
Accrued capital expenditures	$ 97	$ 103	$ 75