Balance Sheets - APC (Parenthetical) - USD ($)	12 Months Ended
	Dec. 31, 2021	Dec. 31, 2020
Common Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized (in shares)	1,500,000,000	1,500,000,000
Redeemable Preferred Stock
Cumulative preferred stock
Annual dividend requirement	$ 15,000,000	$ 15,000,000
Redeemable Preferred Stock, $100 par or stated value
Cumulative preferred stock
Par value (in dollars per share)	$ 100	$ 100
Shares authorized (in shares)	10,000,000	10,000,000
Shares outstanding (in shares)	500,000	500,000
Redeemable Preferred Stock, $100 par or stated value | Minimum
Cumulative preferred stock
Dividend rate	4.20%	4.20%
Redeemable Preferred Stock, $100 par or stated value | Maximum
Cumulative preferred stock
Dividend rate	4.92%	4.92%
Redeemable Preferred Stock, $1 par value
Cumulative preferred stock
Par value (in dollars per share)	$ 1	$ 1
Dividend rate	5.00%	5.00%
Shares authorized (in shares)	28,000,000	28,000,000
Shares outstanding (in shares)	10,000,000	10,000,000
Alabama Power
Common Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 40	$ 40
Common stock, shares authorized (in shares)	40,000,000	40,000,000
Common stock, shares outstanding (in shares)	31,000,000	31,000,000
Alabama Power | Redeemable Preferred Stock
Cumulative preferred stock
Annual dividend requirement	$ 15,000,000	$ 15,000,000
Alabama Power | Redeemable Preferred Stock, $100 par or stated value
Cumulative preferred stock
Par value (in dollars per share)	$ 100	$ 100
Shares authorized (in shares)	3,900,000	3,900,000
Shares outstanding (in shares)	500,000	500,000
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | Minimum
Cumulative preferred stock
Dividend rate	4.20%	4.20%
Alabama Power | Redeemable Preferred Stock, $100 par or stated value | Maximum
Cumulative preferred stock
Dividend rate	4.92%	4.92%
Alabama Power | Redeemable Preferred Stock, $1 par value
Cumulative preferred stock
Par value (in dollars per share)	$ 1	$ 1
Dividend rate	5.00%	5.00%
Shares authorized (in shares)	27,500,000	27,500,000
Shares outstanding (in shares)	10,000,000	10,000,000
Alabama Power | Redeemable Preferred Stock, $25 stated value
Cumulative preferred stock
Par value (in dollars per share)	$ 25	$ 25