Consolidated Balance Sheets - Southern (Parenthetical) - USD ($) $ in Millions	Dec. 31, 2023	Dec. 31, 2022
Statement of Financial Position [Abstract]
Other intangible assets, amortization	$ 376	$ 340
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
Common stock, shares issued (in shares)	1,100,000,000	1,100,000,000
Treasury stock (in shares)	1,000,000.0	1,000,000.0