Revenue Recognition - Disaggregated Revenues (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021	Dec. 31, 2020
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	$ 31,488	$ 26,777	$ 8,690
Mark-to-market for economic hedging activities	1,248	2,716	(119)
Revenues	31,543	26,989	9,093
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	35	(22)	18
Retail Revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	110
Retail Revenue | Home
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10,761	9,549	6,331
Retail Revenue | Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	18,961	14,012	1,129
Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	29,722	23,561	7,460
Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,250	1,215	539
Derivative revenue	(8)	136	105
Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	272	775	680
Derivative revenue	33	149	156
Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	(83)	(164)	95
Less: Realized and unrealized ASC 815 revenue	20	234	385
Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	421	1,632	319
Contract amortization	(39)	(30)	0
Total operating revenues
Disaggregation of Revenue [Line Items]
Revenues	31,543	26,989	9,093
Other derivative revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	(32)	113	29
Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(15)	(6)	(7)
Revenues	17	10	(4)
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	1	0	0
Corporate/Eliminations | Retail Revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	0
Corporate/Eliminations | Retail Revenue | Home
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	(1)	(2)
Corporate/Eliminations | Retail Revenue | Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Corporate/Eliminations | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(1)	(1)	(2)
Corporate/Eliminations | Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	32	7	(1)
Derivative revenue	31	3	(5)
Corporate/Eliminations | Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	(1)
Derivative revenue	0	0	0
Corporate/Eliminations | Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	1	13	8
Less: Realized and unrealized ASC 815 revenue	31	16	3
Corporate/Eliminations | Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	(15)	(9)	(8)
Contract amortization	0	0	0
Corporate/Eliminations | Total operating revenues
Disaggregation of Revenue [Line Items]
Revenues	17	10	(4)
Corporate/Eliminations | Other derivative revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	(1)	0	0
Texas | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	10,059	10,165	6,282
Revenues	10,057	10,295	6,312
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	0	0	0
Texas | Operating Segments | Retail Revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	0
Texas | Operating Segments | Retail Revenue | Home
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	6,388	5,659	5,020
Texas | Operating Segments | Retail Revenue | Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	3,229	2,745	1,034
Texas | Operating Segments | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	9,617	8,404	6,054
Texas | Operating Segments | Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	111	329	24
Derivative revenue	0	0	0
Texas | Operating Segments | Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	0	0	0
Derivative revenue	0	0	0
Texas | Operating Segments | Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	2	(3)	2
Less: Realized and unrealized ASC 815 revenue	(2)	130	30
Texas | Operating Segments | Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	327	1,565	232
Contract amortization	0	0	0
Texas | Operating Segments | Total operating revenues
Disaggregation of Revenue [Line Items]
Revenues	10,057	10,295	6,312
Texas | Operating Segments | Other ancillary revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer		1,300
Texas | Operating Segments | Other derivative revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	(4)	133	28
Texas | Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenues	(4)	(5)	(6)
East | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	16,686	12,866	1,934
Revenues	16,763	13,025	2,249
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	(7)	(25)	1
East | Operating Segments | Retail Revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	110
East | Operating Segments | Retail Revenue | Home
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,088	1,832	1,210
East | Operating Segments | Retail Revenue | Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	13,768	10,030	95
East | Operating Segments | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	15,856	11,862	1,305
East | Operating Segments | Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	641	508	183
Derivative revenue	(31)	131	67
East | Operating Segments | Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	232	718	620
Derivative revenue	33	149	156
East | Operating Segments | Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	(30)	(88)	88
Less: Realized and unrealized ASC 815 revenue	84	184	314
East | Operating Segments | Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	104	51	53
Contract amortization	(40)	(26)	0
East | Operating Segments | Total operating revenues
Disaggregation of Revenue [Line Items]
Revenues	16,763	13,025	2,249
East | Operating Segments | Other derivative revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	2	(8)	3
East | Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenues	26	18	6
West/Services/Other | Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,758	3,752	481
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	41	3	17
West/Services/Other | Operating Segments | Retail Revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	0
West/Services/Other | Operating Segments | Retail Revenue | Home
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	2,286	2,059	103
West/Services/Other | Operating Segments | Retail Revenue | Business
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	1,964	1,237	0
West/Services/Other | Operating Segments | Total retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	4,250	3,296	103
West/Services/Other | Operating Segments | Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	466	371	333
Derivative revenue	(8)	2	43
West/Services/Other | Operating Segments | Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	40	57	61
Derivative revenue	0	0	0
West/Services/Other | Operating Segments | Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	(56)	(86)	(3)
Less: Realized and unrealized ASC 815 revenue	(93)	(96)	38
West/Services/Other | Operating Segments | Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contract with customer	5	25	42
Contract amortization	1	(4)	0
West/Services/Other | Operating Segments | Total operating revenues
Disaggregation of Revenue [Line Items]
Revenues	4,706	3,659	536
West/Services/Other | Operating Segments | Other derivative revenue
Disaggregation of Revenue [Line Items]
Derivative revenue	$ (29)	$ (12)	$ (2)