Cover
| Cover | Sep. 13, 2021 |
| Document Information [Line Items] | |
| City Area Code | (865) |
| Local Phone Number | 632-2101 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Entity Address, Postal Zip Code | 37902 |
| Entity Address, Address Line One | 400 W. Summit Hill Drive |
| Entity Address, City or Town | Knoxville |
| Entity Address, State or Province | TN |
| Entity File Number | 000-52313 |
| Entity Tax Identification Number | 62-0474417 |
| Entity Registrant Name | TENNESSEE VALLEY AUTHORITY |
| Document Period End Date | Sep. 13, 2021 |
| Document Type | 8-K |
| Entity Central Index Key | 0001376986 |
| Document Fiscal Year Focus | 2021 |
| Document Fiscal Period Focus | FY |
| Amendment Flag | false |
| Entity Incorporation, State or Country Code | X1 |