Condensed Statements of Common Stockholders' Equity (Unaudited) - MPC - USD ($) shares in Millions, $ in Millions	Total	Common Stock	Paid-In Capital	Retained Earnings (Accumulated Deficit)	Accumulated Other Comprehensive Income (Loss)	Mississippi Power	Mississippi Power Common Stock	Mississippi Power Paid-In Capital	Mississippi Power Retained Earnings (Accumulated Deficit)
Beginning balance (in shares) at Dec. 31, 2021							1
Beginning balance at Dec. 31, 2021	$ 32,276	$ 5,279	$ 11,950	$ 10,929	$ (237)	$ 1,867	$ 38	$ 4,582	$ (2,753)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	1,032					42			42
Capital contributions from parent company						51		51
Cash dividends on common stock	(702)			(702)		(43)			(43)
Other	7		7	2
Ending balance (in shares) at Mar. 31, 2022							1
Ending balance at Mar. 31, 2022	32,629	5,286	11,994	11,261	(195)	1,917	$ 38	4,633	(2,754)
Beginning balance (in shares) at Dec. 31, 2022							1
Beginning balance at Dec. 31, 2022	34,532	5,417	13,673	11,538	(167)	1,931	$ 38	4,652	(2,759)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	862					58			58
Cash dividends on common stock	(742)			(742)		(46)			(46)
Other	0		2
Ending balance (in shares) at Mar. 31, 2023							1
Ending balance at Mar. 31, 2023	$ 34,562	$ 5,421	$ 13,715	$ 11,658	$ (211)	$ 1,943	$ 38	$ 4,652	$ (2,747)