| Document And Entity Information | Jun. 13, 2023 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 13, 2023 |
| Entity Registrant Name | OLD DOMINION ELECTRIC COOPERATIVE |
| Entity Central Index Key | 0000885568 |
| Entity Emerging Growth Company | false |
| Entity File Number | 000-50039 |
| Entity Incorporation, State or Country Code | VA |
| Entity Tax Identification Number | 23-7048405 |
| Entity Address, Address Line One | 4201 Dominion Boulevard |
| Entity Address, City or Town | Glen Allen |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 23060 |
| City Area Code | 804 |
| Local Phone Number | 747-0592 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | NONE |
