v3.25.2
Document and Entity Information - shares
6 Months Ended
Jun. 30, 2025
Aug. 04, 2025
Entity Information [Line Items]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 01-32665  
Entity Registrant Name BOARDWALK PIPELINE PARTNERS, LP  
Entity Incorporation, State DE  
Entity Tax Identification Number 20-3265614  
Entity Address, Address Line One 9 Greenway Plaza,  
Entity Address, Address Line Two Suite 2800  
Entity Address, City Houston,  
Entity Address, State TX  
Entity Address, Postal Zip Code 77046  
City Area Code (866)  
Local Phone Number 913-2122  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Non-accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Amendment Flag false  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q2  
Entity Central Index Key 0001336047  
Current Fiscal Year End Date --12-31  
Entity Common Stock, Shares Outstanding   0