v3.25.2
Financing (Details) - USD ($)
6 Months Ended
Jun. 30, 2025
Dec. 31, 2024
Unsecured Debt    
Debt Instrument [Line Items]    
Weighted-average interest rates 4.95% 4.95%
Unsecured Debt | Total Notes And Debentures    
Debt Instrument [Line Items]    
Total notes and debentures $ 3,300,000,000 $ 3,300,000,000
Unsecured Debt | Boardwalk Pipelines 5.95% Notes Due 2026    
Debt Instrument [Line Items]    
Short-Term Debt, Refinanced, Amount 550,000,000.0  
Line of Credit    
Line of Credit Facility [Abstract]    
Line of credit, outstanding borrowings 0 0
Available borrowing capacity 1,000,000,000.0 $ 1,000,000,000.0
Line of Credit | Amendment No. 3 Credit Agreement - 2021    
Line of Credit Facility [Abstract]    
Maximum borrowing capacity 1,000,000,000.0  
Line of Credit | Amendment No. 5 Credit Agreement - 2023    
Line of Credit Facility [Abstract]    
Maximum borrowing capacity $ 912,200,000