Segment Information - MEC (Details) $ in Millions	12 Months Ended
	Dec. 31, 2022 USD ($) operatingSegment reportableSegment	Dec. 31, 2021 USD ($)	Dec. 31, 2020 USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | operatingSegment	8
Revenues	$ 26,337	$ 25,150	$ 20,952
Operating income (loss)	5,241	5,327	4,291
Interest expense	2,216	2,118	2,021
Income tax (benefit) expense	(1,916)	(1,132)	308
Net income attributable to parent	2,721	5,790	6,943
Capitalized expenditures	7,505	6,611	6,765
Assets	$ 133,840	132,065	127,316
MEC
Segment Reporting Information [Line Items]
Number of reportable segments | reportableSegment	2
Revenues	$ 4,025	3,547	2,720
Depreciation and amortization	1,168	914	716
Operating income (loss)	438	416	448
Interest expense	313	302	304
Income tax (benefit) expense	(770)	(675)	(570)
Net income attributable to parent	961	894	826
Capitalized expenditures	1,869	1,912	1,836
Assets	23,978	23,257	21,437
MEC | Other
Segment Reporting Information [Line Items]
Revenues	7	15	8
Income tax (benefit) expense	0	(1)	0
Net income attributable to parent	0	0	1
Assets	1	1	1
MEC | Regulated electric | Operating segments
Segment Reporting Information [Line Items]
Revenues	2,988	2,529	2,139
Depreciation and amortization	1,112	861	667
Operating income (loss)	372	358	384
Interest expense	290	279	281
Income tax (benefit) expense	(779)	(677)	(584)
Net income attributable to parent	931	844	780
Capitalized expenditures	1,742	1,806	1,704
Assets	22,092	21,385	19,892
MEC | Regulated natural gas | Operating segments
Segment Reporting Information [Line Items]
Revenues	1,030	1,003	573
Depreciation and amortization	56	53	49
Operating income (loss)	66	58	64
Interest expense	23	23	23
Income tax (benefit) expense	9	3	14
Net income attributable to parent	30	50	45
Capitalized expenditures	127	106	132
Assets	$ 1,885	$ 1,871	$ 1,544