CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	Sep. 30, 2017	Dec. 31, 2016
Property, Plant and Equipment, Net	$ 35,384	$ 32,931	[1]
Long-term Debt and Capital Lease Obligations	$ 14,803	$ 14,429	[1]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized	50,000,000	50,000,000
Preferred stock, shares issued	0	0
Common stock, shares authorized	750,000,000	750,000,000
Common stock, shares outstanding	251,000,000	250,000,000
Common stock, No par value (in dollars per share)	$ 0	$ 0
Otay Mesa VIE [Member]
Property, Plant and Equipment, Net	$ 328	$ 354
Long-term Debt and Capital Lease Obligations	286	293
San Diego Gas and Electric Company [Member]
Property, Plant and Equipment, Net	14,434	13,250	[1]
Long-term Debt and Capital Lease Obligations	$ 5,339	$ 4,658	[1]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized	45,000,000	45,000,000
Preferred stock, shares issued	0	0
Common stock, shares authorized	255,000,000	255,000,000
Common stock, shares outstanding	117,000,000	117,000,000
Common stock, No par value (in dollars per share)	$ 0	$ 0
San Diego Gas and Electric Company [Member] | Otay Mesa VIE [Member]
Property, Plant and Equipment, Net	$ 328	$ 354
Long-term Debt and Capital Lease Obligations	286	293
Southern California Gas Company [Member]
Property, Plant and Equipment, Net	10,893	10,252	[1]
Long-term Debt and Capital Lease Obligations	$ 2,484	$ 2,982	[1]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized	11,000,000	11,000,000
Preferred stock, shares issued	1,000,000	1,000,000
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares outstanding	91,000,000	91,000,000
Common stock, No par value (in dollars per share)	$ 0	$ 0

[1] Derived from audited financial statements.