v3.25.2
Cover Page Document
Sep. 16, 2025
Document Information [Line Items]  
Document Type 8-K
Document Period End Date Sep. 16, 2025
Entity File Number 001-37803
Entity Registrant Name Southern Power Company
Entity Tax Identification Number 58-2598670
Entity Incorporation, State or Country Code DE
Entity Address, Address Line One 30 Ivan Allen Jr. Boulevard, N.W.
Entity Address, City or Town Atlanta
Entity Address, State or Province GA
Entity Address, Postal Zip Code 30308
City Area Code 404
Local Phone Number 506-5000
Written Communications false
Soliciting Material false
Pre-commencement Tender Offer false
Pre-commencement Issuer Tender Offer false
Title of 12(b) Security Series 2016B 1.850% Senior Notes due 2026
Trading Symbol SO/26A
Security Exchange Name NYSE
Entity Emerging Growth Company false
Entity Central Index Key 0001160661
Amendment Flag false