| Document and Entity Information | May 05, 2022 |
| Cover [Abstract] | |
| Entity Registrant Name | NATIONAL FUEL GAS COMPANY |
| Amendment Flag | false |
| Entity Central Index Key | 0000070145 |
| Document Type | 8-K |
| Document Period End Date | May 5, 2022 |
| Entity Incorporation, State or Country Code | NJ |
| Entity File Number | 1-3880 |
| 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 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, par value $1.00 per share |
| Trading Symbol | NFG |
| Security Exchange Name | NYSE |
| Entity Emerging Growth Company | false |
