CONDENSED CONSOLIDATED BALANCE SHEETS (Parentheticals) - USD ($) $ in Millions	9 Months Ended	12 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Property, plant and equipment, net	$ 35,520	$ 34,439	[1]
Current portion of long-term debt and finance leases	1,623	1,644	[1]
Long-term debt and finance leases	$ 20,995	$ 20,903	[1]
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)	282,000,000	274,000,000
Otay Mesa VIE [Member]
Property, plant and equipment, net		$ 295
Current portion of long-term debt and finance leases		28
Long-term debt and finance leases		190
San Diego Gas and Electric Company [Member]
Property, plant and equipment, net	$ 16,611	16,310	[1]
Current portion of long-term debt and finance leases	55	81	[1]
Long-term debt and finance leases	$ 6,307	$ 6,138	[1]
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
San Diego Gas and Electric Company [Member] | Otay Mesa VIE [Member]
Property, plant and equipment, net		$ 295
Current portion of long-term debt and finance leases		28
Long-term debt and finance leases		190
Southern California Gas Company [Member]
Property, plant and equipment, net	$ 12,963	12,439	[1]
Current portion of long-term debt and finance leases	5	3	[1]
Long-term debt and finance leases	$ 3,784	$ 3,427	[1]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred stock, shares authorized (in shares)	11,000,000	11,000,000
Preferred stock, shares issued (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, Dividend Rate, Percentage	6.00%	6.00%
Preferred stock, shares issued (in shares)	17,250,000	17,250,000
Preferred stock, shares outstanding (in shares)	17,250,000	17,250,000
Convertible Preferred Stock Series B [Member]
Stockholders' Equity Attributable to Parent [Abstract]
Preferred Stock, Dividend Rate, Percentage	6.75%	6.75%
Preferred stock, shares issued (in shares)	5,750,000	5,750,000
Preferred stock, shares outstanding (in shares)	5,750,000	5,750,000

[1] Derived from audited financial statements.