v3.26.3
Acquisitions - Boardwalk Pipelines (Details) - USD ($)
$ in Millions
Apr. 30, 2026
Sep. 30, 2026
Dec. 31, 2025
Business Combination [Line Items]      
Goodwill   $ 475 $ 349
Spire Marketing LLC      
Business Combination [Line Items]      
Business combination, consideration transferred $ 206    
Assets acquired 299    
Liabilities assumed 93    
Goodwill 127    
Derivative assets acquired $ 74