Revenue Recognition (Tables)

6 Months Ended

Jun. 30, 2021

Revenue From Contract With Customer [Abstract]

Disaggregation of Revenue

DESC has disaggregated operating revenues by customer class as follows:

	Three Months Ended				Three Months Ended				Six Months Ended				Six Months Ended
	June 30, 2021				June 30, 2020				June 30, 2021				June 30, 2020
(millions)	Electric		Gas		Electric		Gas		Electric		Gas		Electric		Gas
Customer class:
Residential	$	271	$	38	$	261	$	33	$	546	$	136	$	513	$	112
Commercial		199		26		177		20		374		65		352		53
Industrial		95		18		83		12		183		40		163		29
Other		38		7		27		4		71		12		57		8
Revenues from contracts with    customers		603		89		548		69		1,174		253		1,085		202
Other revenues		—		—		7		—		8		1		9		—
Total Operating Revenues	$	603	$	89	$	555	$	69	$	1,182	$	254	$	1,094	$	202