Statements of Operations - MEC - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020	Dec. 31, 2019
Operating revenue:
Total operating revenue	$ 25,150	$ 20,952	$ 19,844
Operating expenses:
Cost of fuel and energy	5,504	4,187	4,586
Total operating expenses	19,823	16,661	15,694
Operating income	5,327	4,291	4,150
Other income (expense):
Interest expense	(2,118)	(2,021)	(1,912)
Allowance for equity funds	126	165	173
Other, net	(17)	88	97
Total other income (expense)	(33)	3,180	(1,736)
Income (loss) before income tax expense (benefit) and equity income (loss)	5,294	7,471	2,414
Income tax (benefit) expense	(1,132)	308	(598)
Net income (loss) attributable to parent	5,790	6,943	2,950
MEC
Operating revenue:
Total operating revenue	3,547	2,720	2,925
Operating expenses:
Operations and maintenance	775	754	800
Depreciation and amortization	914	716	639
Property and other taxes	142	135	126
Total operating expenses	3,131	2,272	2,377
Operating income	416	448	548
Other income (expense):
Interest expense	(302)	(304)	(281)
Allowance for borrowed funds	13	15	27
Allowance for equity funds	39	45	78
Other, net	53	52	50
Total other income (expense)	(197)	(192)	(126)
Income (loss) before income tax expense (benefit) and equity income (loss)	219	256	422
Income tax (benefit) expense	(675)	(570)	(371)
Net income (loss) attributable to parent	894	826	793
Regulated electric | MEC
Operating revenue:
Total operating revenue	2,529	2,139	2,237
Operating expenses:
Cost of fuel and energy	539	339	399
Regulated natural gas and other | MEC
Operating revenue:
Total operating revenue	1,018	581	688
Operating expenses:
Cost of fuel and energy	$ 761	$ 328	$ 413