Revenue Recognition - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended
Mar. 31, 2023	Mar. 31, 2022
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 7,515	$ 7,989
Mark-to-market for economic hedging activities	(1,944)	2,277
Revenue	7,722	7,896
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	8	2
Derivative revenue	(1,932)	2,263
Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(1)	(3)
Revenue	(10)	17
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	0	0
Retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	7,363	7,570
Derivative revenue	27
Retail revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Derivative revenue	0
Energy revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	128	278
Derivative revenue	66	29
Energy revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2	5
Derivative revenue	2	4
Capacity revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	42	116
Derivative revenue	6	13
Capacity revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Derivative revenue	0	0
Derivative revenue
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	91	(133)
Less: Realized and unrealized ASC 815 revenue	199	(95)
Derivative revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	(11)	17
Less: Realized and unrealized ASC 815 revenue	(9)	20
Other revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	109	74
Contract amortization	(11)	(9)
Other revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	(1)	(5)
Contract amortization	0	0
Total operating revenue
Disaggregation of Revenue [Line Items]
Revenue	7,722	7,896
Total operating revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue	(10)	17
Other revenue, derivative
Disaggregation of Revenue [Line Items]
Derivative revenue	9	(4)
Other revenue, derivative \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Derivative revenue	0	(1)
Home \| Retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,660	2,565
Home \| Retail revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Business \| Retail revenue
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,703	5,005
Business \| Retail revenue \| Corporate/Eliminations
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Texas \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	2,036	2,027
Revenue	2,034	2,020
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	0	0
Texas \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,958	1,946
Derivative revenue	0
Texas \| Energy revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4	15
Derivative revenue	0	0
Texas \| Capacity revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0	0
Derivative revenue	0	0
Texas \| Derivative revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	0	(2)
Less: Realized and unrealized ASC 815 revenue	(2)	(7)
Texas \| Other revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	72	61
Contract amortization	0	0
Texas \| Total operating revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	2,034	2,020
Texas \| Other revenue, derivative \| Operating Segments
Disaggregation of Revenue [Line Items]
Derivative revenue	(2)	(5)
Texas \| Home \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,236	1,283
Texas \| Business \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	722	663
East \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,064	4,790
Revenue	4,176	4,715
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	(1)	(9)
East \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	4,016	4,521
Derivative revenue	27
East \| Energy revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	74	204
Derivative revenue	47	45
East \| Capacity revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	41	115
Derivative revenue	6	13
East \| Derivative revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	35	(130)
Less: Realized and unrealized ASC 815 revenue	113	(66)
East \| Other revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	21	14
Contract amortization	(11)	(9)
East \| Total operating revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	4,176	4,715
East \| Other revenue, derivative \| Operating Segments
Disaggregation of Revenue [Line Items]
Derivative revenue	(2)	6
East \| Home \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	651	579
East \| Business \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	3,365	3,942
West/Services/Other \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,268	1,175
Revenue	1,374	1,144
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	9	11
West/Services/Other \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1,241	1,103
Derivative revenue	0
West/Services/Other \| Energy revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	48	54
Derivative revenue	17	(20)
West/Services/Other \| Capacity revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	1	1
Derivative revenue	0	0
West/Services/Other \| Derivative revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	67	(18)
Less: Realized and unrealized ASC 815 revenue	97	(42)
West/Services/Other \| Other revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	17	4
Contract amortization	0	0
West/Services/Other \| Total operating revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	1,374	1,144
West/Services/Other \| Other revenue, derivative \| Operating Segments
Disaggregation of Revenue [Line Items]
Derivative revenue	13	(4)
West/Services/Other \| Home \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	625	703
West/Services/Other \| Business \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	616	$ 400
Vivint(a) \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	148
Revenue	148
Less: Revenues accounted for under topics other than ASC 606 and ASC 815	0
Vivint(a) \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	148
Derivative revenue	0
Vivint(a) \| Energy revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Derivative revenue	0
Vivint(a) \| Capacity revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Derivative revenue	0
Vivint(a) \| Derivative revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Mark-to-market for economic hedging activities	0
Less: Realized and unrealized ASC 815 revenue	0
Vivint(a) \| Other revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	0
Contract amortization	0
Vivint(a) \| Total operating revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue	148
Vivint(a) \| Other revenue, derivative \| Operating Segments
Disaggregation of Revenue [Line Items]
Derivative revenue	0
Vivint(a) \| Home \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	148
Vivint(a) \| Business \| Retail revenue \| Operating Segments
Disaggregation of Revenue [Line Items]
Revenue from contracts with customers	$ 0

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