v3.25.2
Document And Entity Information - $ / shares
 9 Months Ended
Jun. 30, 2025
Jul. 30, 2025
Cover [Abstract]    
Document Type 10-Q  
Document Quarterly Report true  
Document Period End Date Jun. 30, 2025  
Document Transition Report false  
Entity File Number 1-3880  
Entity Registrant Name NATIONAL FUEL GAS COMPANY  
Entity Incorporation, State or Country Code NJ  
Entity Tax Identification Number 13-1086010  
Entity Address, Address Line One 6363 Main Street  
Entity Address, City or Town Williamsville,  
Entity Address, State or Province NY  
Entity Address, Postal Zip Code 14221  
City Area Code 716  
Local Phone Number 857-7000  
Title of 12(b) Security Common Stock, par value $1.00 per share  
Trading Symbol NFG  
Security Exchange Name NYSE  
Entity Current Reporting Status Yes  
Entity Interactive Data Current Yes  
Entity Filer Category Large Accelerated Filer  
Entity Small Business false  
Entity Emerging Growth Company false  
Entity Shell Company false  
Entity Listing, Par Value Per Share $ 1.00  
Entity Common Stock, Shares Outstanding   90,363,646
Entity Central Index Key 0000070145  
Current Fiscal Year End Date --09-30  
Document Fiscal Year Focus 2025  
Document Fiscal Period Focus Q3  
Amendment Flag false