CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (USD $) In Millions, unless otherwise specified	9 Months Ended
	Sep. 30, 2012		Sep. 30, 2011
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	$ 615		$ 1,073	[1]
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	803		729	[1]
Deferred income taxes and investment tax credits	(45)		211	[1]
Remeasurement of equity method investments			(277)	[1]
Equity earnings	346		(41)	[1]
Fixed-price contracts and other derivatives	1		(7)	[1]
Other	(8)		(43)	[1]
Net change in other working capital components	(373)		(75)	[1]
Distributions from RBS Sempra Commodities LLP, operating activities			53	[1]
Changes in other assets	202		31	[1]
Changes in other liabilities	147		(11)	[1]
Net cash provided by operating activities	1,688		1,643	[1]
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(2,241)		(2,031)	[1]
Expeditures for investments and acquisition of businesses, net of cash acquired	(359)		(696)	[1]
Proceeds from sale of joint venture	9
Distributions from RBS Sempra Commodities LLP, investing activities			374	[1]
Distributions from investments	43		47	[1]
Purchases of nuclear decommissioning and other trust assets	(534)		(399)	[1]
Proceeds from sales by nuclear decommissioning and other trusts	534		398	[1]
Decrease in restricted cash	89		473	[1]
Increase in restricted cash	(105)		(450)	[1]
Other cash flows from investing activities	(12)		(20)	[1]
Net cash used in investing activities	(2,576)		(2,304)	[1]
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(405)		(325)	[1]
Preferred dividends paid by subsidiaries	(5)		(6)	[1]
Issuances of common stock	50		22	[1]
Repurchases of common stock	(16)		(18)	[1]
Redemption of subsidiary preferred stock			(80)	[1]
Issuances of debt (maturities greater than 90 days)	2,294		1,525	[1]
Payments on debt (maturities greater than 90 days)	(563)		(366)	[1]
Increase (decrease) in short-term debt, net	(142)		(300)	[1]
Distributions to noncontrolling interests	(36)		(10)	[1]
Purchase of noncontrolling interests			(43)	[1]
Other cash flows from financing activities	(20)		5	[1]
Net cash provided by (used in) financing activities	1,157		404	[1]
Effect of exchange rate changes on cash and cash equivalents	9		2	[1]
Increase (decrease) in cash and cash equivalents	278		(255)	[1]
Cash and cash equivalents, beginning of period	252	[1],[2]	912	[1]
Cash and cash equivalents, end of period	530		657	[1]
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	278		281
Income tax payments, net of refunds	99		106
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING ACTIVITIES
Accrued capital expenditures	315		306
U. S. Treasury grants receivable	136	[3]
Cash grants previously recorded as investment tax credits	45
Acquisition Of Business [Abstract]
Assets acquired	29		2,831
Cash paid, net of cash acquired	(19)		(611)
Fair of equity method investments immediately prior to the acquisition			(882)
Fair value of noncontrolling interests			(279)
Additional consideration accrued			(32)
Liabilities Assumed	10		1,027
SUPPLEMENTAL DISCLOSURE OF NONCASH FINANCING ACTIVITIES
Dividends declared but not paid	149		119
San Diego Gas and Electric Company and Subsidiary [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	401		283
Adjustments to reconcile net income to net cash provided by operating activities:
Utility depreciation and amortization	359		316
Deferred income taxes and investment tax credits	262		226
Fixed-price contracts and other derivatives	(9)		(13)
Other	(55)		(43)
Net change in other working capital components	(518)		18
Changes in other assets	201		32
Changes in other liabilities	129
Net cash provided by operating activities	770		819
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(998)		(1,162)
Purchases of nuclear decommissioning and other trust assets	(530)		(395)
Proceeds from sales by nuclear decommissioning and other trusts	524		389
Decrease in restricted cash	74		340
Increase in restricted cash	(62)		(355)
Net cash used in investing activities	(992)		(1,183)
CASH FLOWS FROM FINANCING ACTIVITIES
Capital contribution			200
Preferred dividends paid	(4)		(4)
Issuances of long-term debt	249		348
Payments on long-term debt	(7)		(7)
Increase (decrease) in short-term debt, net	2
Contributions from noncontrolling interests			5
Distributions to noncontrolling interests	(22)
Other cash flows from financing activities	(3)		(2)
Net cash provided by (used in) financing activities	215		540
Increase (decrease) in cash and cash equivalents	(7)		176
Cash and cash equivalents, beginning of period	29	[2]	127
Cash and cash equivalents, end of period	22		303
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	96		80
Income tax payments, net of refunds	(121)		59
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING ACTIVITIES
Accrued capital expenditures	87		161
SUPPLEMENTAL DISCLOSURE OF NONCASH FINANCING ACTIVITIES
Dividends declared but not paid	1		1
Southern California Gas Company [Member]
CASH FLOWS FROM OPERATING ACTIVITIES
Net income	191		209
Adjustments to reconcile net income to net cash provided by operating activities:
Utility depreciation and amortization	268		246
Deferred income taxes and investment tax credits	39		79
Other	(9)		(4)
Net change in other working capital components	240		(46)
Changes in other assets	4		17
Changes in other liabilities	13		(6)
Net cash provided by operating activities	746		495
CASH FLOWS FROM INVESTING ACTIVITIES
Expenditures for property, plant and equipment	(462)		(499)
Increase (decrease) in loans to affiliates, net	(257)		(96)
Net cash used in investing activities	(719)		(595)
CASH FLOWS FROM FINANCING ACTIVITIES
Common dividends paid	(150)		(50)
Preferred dividends paid	(1)		(1)
Issuances of long-term debt	348
Payments on long-term debt			(250)
Debt issuances costs	(3)
Net cash provided by (used in) financing activities	194		(301)
Increase (decrease) in cash and cash equivalents	221		(401)
Cash and cash equivalents, beginning of period	36	[2]	417
Cash and cash equivalents, end of period	257		16
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION
Interest payments, net of amounts capitalized	36		39
Income tax payments, net of refunds	46		17
SUPPLEMENTAL DISCLOSURE OF NONCASH INVESTING ACTIVITIES
Accrued capital expenditures	$ 69		$ 81

[1] As adjusted for the retrospective effect of a change in accounting principle as we discuss in Note 1.

[2] Derived from audited financial statements.

[3] Cash grants, excluding $45 million previously recorded in 2011 as investment tax credits.