Consolidated Balance Sheets - Southern (Parenthetical) - USD ($) shares in Millions, $ in Millions	Dec. 31, 2024	Dec. 31, 2023
Statement of Financial Position [Abstract]
Other intangible assets, amortization	$ 412	$ 376
Common Stockholders' Equity:
Common stock, par value (in dollars per share)	$ 5	$ 5
Common stock, shares authorized (in shares)	1,500.0	1,500.0
Common stock, shares issued (in shares)	1,100.0	1,100.0
Treasury stock (in shares)	1.0	1.0