FAIR VALUE MEASUREMENTS (Details) (USD $) In Millions	3 Months Ended			6 Months Ended
	Jun. 30, 2011		Jun. 30, 2010	Jun. 30, 2011		Jun. 30, 2010	Dec. 31, 2010
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Unamortized Discount	$ 22			$ 22			$ 22
Capital Lease Obligations	214			214			221
Commercial Paper Noncurrent	200			200			800
Schedule of Available-for-sale Securities [Line Items]
Cost	528			528			514
Gross unrealized gains	285			285			261
Gross unrealized losses	(5)			(5)			(6)
Estimated fair value	808			808			769
Proceeds from sales	48		110	90		150
Gross realized gains	1		2	2		3
Gross realized losses	(1)		(5)	(2)		(7)
Derivative, Fair Value, Gross Amount Not Offset Against Collateral, Net [Line Items]
Fair value of cash collateral receivables not offset against derivatives	30			30			32
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - equity securities	483			483			460
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	172			172			174
Nuclear decomissioning trusts - Municipal debt securities	118			118			100
Nuclear decommissioning trusts - Other debt securities	24			24			25
Nuclear decommissioning trusts - Total debt securities	314			314			299
Total nuclear decommissioning trusts	797	[1]		797	[1]		759	[1]
Interest rate instruments, assets	39			39			34
Commodity contracts subject to rate recovery, assets	25			25			28
Commodity contracts not subject to rate recovery, assets	58			58			53
Investments	13			13			1
Total fair value of assets measured on a recurring basis	932			932			875
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, liabilities	87			87			82
Commodity contracts subject to rate recovery, liabilities	4			4			8
Commodity contracts not subject to rate recovery, liabilities	51			51			67
Total fair value of liabilities measured on a recurring basis	142			142			157
Fair Value, Assets Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance at beginning of period	3		9	2		10
Realized and unrealized gains (losses)	6		(2)	12		(4)
Allocated transmission instruments	1			2
Settlements	(7)			(13)		1
Balance at end of period	3		7	3		7
San Diego Gas and Electric Company and Subsidiary [Member] | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Total long-term debt	3,300	[2]		3,300	[2]		3,305	[2]
Fair value of financial instruments, Contingently redeemable preferred stock	79			79			79
Southern California Gas Company [Member] | Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Total long-term debt	1,312	[3]		1,312	[3]		1,566	[3]
Fair value of financial instruments, Preferred stock	22			22			22
Carrying Amount
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Investments in affordable housing partnerships	25	[4]		25	[4]		28	[4]
Fair value of financial instruments, Total long-term debt	9,400	[5]		9,400	[5]		8,330	[5]
Fair value of financial instruments, Due to unconsolidated affiliate							2	[6]
Fair value of financial instruments, Preferred stock of subsidiaries	99			99			179
San Diego Gas and Electric Company and Subsidiary [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Total long-term debt	3,346	[2]		3,346	[2]		3,300	[2]
Fair value of financial instruments, Contingently redeemable preferred stock	80			80			78
Southern California Gas Company [Member] | Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Total long-term debt	1,380	[3]		1,380	[3]		1,638	[3]
Fair value of financial instruments, Preferred stock	22			22			21
Fair Value
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Fair value of financial instruments, Investments in affordable housing partnerships	58	[4]		58	[4]		58	[4]
Fair value of financial instruments, Total long-term debt	10,001	[5]		10,001	[5]		8,883	[5]
Fair value of financial instruments, Due to unconsolidated affiliate							2	[6]
Fair value of financial instruments, Preferred stock of subsidiaries	101			101			166
San Diego Gas and Electric Company and Subsidiary [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Unamortized Discount	9			9			9
Capital Lease Obligations	198			198			202
Derivative, Fair Value, Gross Amount Not Offset Against Collateral, Net [Line Items]
Fair value of cash collateral receivables not offset against derivatives	18			18			25
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - equity securities	483			483			460
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	172			172			174
Nuclear decomissioning trusts - Municipal debt securities	118			118			100
Nuclear decommissioning trusts - Other debt securities	24			24			25
Nuclear decommissioning trusts - Total debt securities	314			314			299
Total nuclear decommissioning trusts	797	[1]		797	[1]		759	[1]
Commodity contracts subject to rate recovery, assets	21			21			26
Commodity contracts not subject to rate recovery, assets	1			1			2
Total fair value of assets measured on a recurring basis	819			819			787
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, liabilities	61			61			58
Commodity contracts subject to rate recovery, liabilities	3			3			2
Total fair value of liabilities measured on a recurring basis	64			64			60
San Diego Gas and Electric Company and Subsidiary [Member] | Level 1
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - equity securities	483			483			460
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	144			144			144
Nuclear decommissioning trusts - Total debt securities	144			144			144
Total nuclear decommissioning trusts	627	[1]		627	[1]		604	[1]
Commodity contracts subject to rate recovery, assets	18			18			24
Commodity contracts not subject to rate recovery, assets	1			1			2
Total fair value of assets measured on a recurring basis	646			646			630
San Diego Gas and Electric Company and Subsidiary [Member] | Level 2
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	28			28			30
Nuclear decomissioning trusts - Municipal debt securities	118			118			100
Nuclear decommissioning trusts - Other debt securities	24			24			25
Nuclear decommissioning trusts - Total debt securities	170			170			155
Total nuclear decommissioning trusts	170	[1]		170	[1]		155	[1]
Total fair value of assets measured on a recurring basis	170			170			155
San Diego Gas and Electric Company and Subsidiary [Member] | Level 3
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, assets	3			3			2
Total fair value of assets measured on a recurring basis	3			3			2
San Diego Gas and Electric Company and Subsidiary [Member] | Level 1
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	42			42			60
Total fair value of liabilities measured on a recurring basis	42			42			60
San Diego Gas and Electric Company and Subsidiary [Member] | Level 2
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, liabilities	61			61			58
Commodity contracts subject to rate recovery, liabilities	3			3			2
Total fair value of liabilities measured on a recurring basis	64			64			60
San Diego Gas and Electric Company and Subsidiary [Member] | Collateral Netted [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	(42)			(42)			(60)
Total fair value of liabilities measured on a recurring basis	(42)			(42)			(60)
Southern California Gas Company [Member]
Fair Value, Balance Sheet Grouping, Financial Statement Captions [Line Items]
Debt Instrument Unamortized Discount	2			2			3
Capital Lease Obligations	15			15			19
Derivative, Fair Value, Gross Amount Not Offset Against Collateral, Net [Line Items]
Fair value of cash collateral receivables not offset against derivatives	3			3			3
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, assets							3
Commodity contracts subject to rate recovery, assets	4			4			2
Commodity contracts not subject to rate recovery, assets	2			2			3
Total fair value of assets measured on a recurring basis	6			6			8
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	1			1
Southern California Gas Company [Member] | Level 1
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, assets	3			3			1
Commodity contracts not subject to rate recovery, assets	2			2			3
Total fair value of assets measured on a recurring basis	5			5			4
Southern California Gas Company [Member] | Level 2
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, assets							3
Commodity contracts subject to rate recovery, assets	1			1			1
Total fair value of assets measured on a recurring basis	1			1			4
Southern California Gas Company [Member] | Level 2
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	1			1
Total Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	296			296			285
Gross unrealized gains	22			22			19
Gross unrealized losses	(4)			(4)			(5)
Estimated fair value	314			314			299
Debt Securities Issued By The U.S. Treasury And Other U.S. Government Corporations And Agencies
Schedule of Available-for-sale Securities [Line Items]
Cost	159	[7]		159	[7]		162
Gross unrealized gains	15	[7]		15	[7]		14
Gross unrealized losses	(2)	[7]		(2)	[7]		(2)
Estimated fair value	172	[7]		172	[7]		174
Municipal Bonds
Schedule of Available-for-sale Securities [Line Items]
Cost	116	[8]		116	[8]		101
Gross unrealized gains	4	[8]		4	[8]		2
Gross unrealized losses	(2)	[8]		(2)	[8]		(3)
Estimated fair value	118	[8]		118	[8]		100
Other Debt Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	21	[9]		21	[9]		22
Gross unrealized gains	3	[9]		3	[9]		3
Estimated fair value	24	[9]		24	[9]		25
Equity Securities
Schedule of Available-for-sale Securities [Line Items]
Cost	221			221			219
Gross unrealized gains	263			263			242
Gross unrealized losses	(1)			(1)			(1)
Estimated fair value	483			483			460
Cash And Cash Equivalents
Schedule of Available-for-sale Securities [Line Items]
Cost	11			11			10
Estimated fair value	11			11			10
Level 1
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - equity securities	483			483			460
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	144			144			144
Nuclear decommissioning trusts - Total debt securities	144			144			144
Total nuclear decommissioning trusts	627	[1]		627	[1]		604	[1]
Commodity contracts subject to rate recovery, assets	21			21			25
Commodity contracts not subject to rate recovery, assets	14			14			9
Investments	13			13			1
Total fair value of assets measured on a recurring basis	675			675			639
Level 1
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	42			42			60
Total fair value of liabilities measured on a recurring basis	42			42			60
Level 2
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Nuclear decommissioning trusts - Debt securities issued by the U.S. Treasury and other U.S. government corporations and agencies	28			28			30
Nuclear decomissioning trusts - Municipal debt securities	118			118			100
Nuclear decommissioning trusts - Other debt securities	24			24			25
Nuclear decommissioning trusts - Total debt securities	170			170			155
Total nuclear decommissioning trusts	170	[1]		170	[1]		155	[1]
Interest rate instruments, assets	39			39			34
Commodity contracts subject to rate recovery, assets	1			1			1
Commodity contracts not subject to rate recovery, assets	48			48			66
Total fair value of assets measured on a recurring basis	258			258			256
Level 2
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Interest rate instruments, liabilities	87			87			82
Commodity contracts subject to rate recovery, liabilities	4			4			8
Commodity contracts not subject to rate recovery, liabilities	51			51			67
Total fair value of liabilities measured on a recurring basis	142			142			157
Level 3
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, assets	3			3			2
Total fair value of assets measured on a recurring basis	3			3			2
Collateral Netted [Member]
Fair Value, Assets Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts not subject to rate recovery, assets	(4)			(4)			(22)
Total fair value of assets measured on a recurring basis	(4)			(4)			(22)
Collateral Netted [Member]
Fair Value, Liabilities Measured on Recurring Basis, Financial Statement Captions [Line Items]
Commodity contracts subject to rate recovery, liabilities	(42)			(42)			(60)
Total fair value of liabilities measured on a recurring basis	$ (42)			$ (42)			$ (60)

[1] Excludes cash balances and cash equivalents.

[2] Before reductions for unamortized discount of $9 million at both June 30, 2011 and December 31, 2010, and excluding capital leases of $198 million at June 30, 2011 and $202 million at December 31, 2010.

[3] Before reductions for unamortized discount of $2 million at June 30, 2011 and $3 million at December 31, 2010, and excluding capital leases of $15 million at June 30, 2011 and $19 million at December 31, 2010.

[4] We discuss our investments in affordable housing partnerships in Note 4 of the Notes to Consolidated Financial Statements in the Annual Report.

[5] Before reductions for unamortized discount of $22 million at both June 30, 2011 and December 31, 2010, and excluding capital leases of $214 million at June 30, 2011 and $221 million at December 31, 2010, and commercial paper classified as long-term debt of $200 million at June 30, 2011 and $800 million at December 31, 2010. We discuss our long-term debt in Note 6 above and Note 5 of the Notes to Consolidated Financial Statements in the Annual Report.

[6] Note payable was extinguished due to the increase in our ownership of Chilquinta Energía S.A. to 100% in the second quarter of 2011.

[7] Maturity dates are 2011-2040.

[8] Maturity dates are 2013-2057.

[9] Maturity dates are 2011-2049.