Amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but is not limited to, notes payable, bonds payable, commercial loans, mortgage loans, convertible debt, subordinated debt and other types of debt.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02(22))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 944
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.7-03(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 210
-Section S99
-Paragraph 1
-Subparagraph (SX 210.9-03(16))
-URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878

Name:	us-gaap_DebtInstrumentCarryingAmount
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

DEBT AND CREDIT FACILITIES - FIRST MORTGAGE BONDS (Details) - USD ($) $ in Millions	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016
San Diego Gas and Electric Company [Member]
First Mortgage Bonds [Line Items]
First mortgage bonds available for future issuance	$ 4,700
Gross long-term debt	4,573		$ 4,349
Southern California Gas Company [Member]
First Mortgage Bonds [Line Items]
First mortgage bonds available for future issuance	1,100
Gross long-term debt	3,000		3,000
First Mortgage Bonds, Due June 2047 [Member] \| San Diego Gas and Electric Company [Member]
First Mortgage Bonds [Line Items]
Gross long-term debt	$ 400	$ 400	$ 0
Stated percentage rate	3.75%	3.75%