CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - shares	Mar. 31, 2021	Dec. 31, 2020
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	50,000,000	50,000,000
Common stock, shares authorized (in shares)	750,000,000	750,000,000
Common stock, shares outstanding (in shares)	303,000,000	288,000,000
San Diego Gas and Electric Company [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	45,000,000	45,000,000
Preferred stock, shares issued (in shares)	0	0
Common stock, shares authorized (in shares)	255,000,000	255,000,000
Common stock, shares outstanding (in shares)	117,000,000	117,000,000
Southern California Gas Company [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	11,000,000	11,000,000
Preferred stock, shares outstanding (in shares)	1,000,000	1,000,000
Common stock, shares authorized (in shares)	100,000,000	100,000,000
Common stock, shares outstanding (in shares)	91,000,000	91,000,000
Convertible Preferred Stock Series A [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares outstanding (in shares)		17,250,000
Convertible Preferred Stock Series B [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares outstanding (in shares)	5,750,000	5,750,000
Series C Preferred Stock [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares outstanding (in shares)	900,000	900,000