| Cover - USD ($) | 12 Months Ended | ||
| Dec. 31, 2022 | Mar. 16, 2023 | Jun. 30, 2022 | |
| Cover [Abstract] | |||
| Document Type | 10-K/A | ||
| Amendment Flag | false | ||
| Document Annual Report | true | ||
| Document Transition Report | false | ||
| Document Period End Date | Dec. 31, 2022 | ||
| Document Fiscal Period Focus | FY | ||
| Document Fiscal Year Focus | 2022 | ||
| Current Fiscal Year End Date | --12-31 | ||
| Entity File Number | 001-3473 | ||
| Entity Registrant Name | HALLADOR ENERGY COMPANY | ||
| Entity Central Index Key | 0000788965 | ||
| Entity Tax Identification Number | 84-1014610 | ||
| Entity Incorporation, State or Country Code | CO | ||
| Entity Address, Address Line One | 1183 East Canvasback Drive | ||
| Entity Address, City or Town | Terre Haute | ||
| Entity Address, State or Province | IN | ||
| Entity Address, Postal Zip Code | 47802 | ||
| City Area Code | 812 | ||
| Local Phone Number | 299.2800 | ||
| Title of 12(b) Security | Common Stock, $0.01 par value per share | ||
| Trading Symbol | HNRG | ||
| Security Exchange Name | NASDAQ | ||
| Entity Well-known Seasoned Issuer | No | ||
| Entity Voluntary Filers | No | ||
| Entity Current Reporting Status | Yes | ||
| Entity Interactive Data Current | Yes | ||
| Entity Filer Category | Accelerated Filer | ||
| Entity Small Business | true | ||
| Entity Emerging Growth Company | false | ||
| Entity Shell Company | false | ||
| Entity Public Float | $ 116,685,277 | ||
| Entity Common Stock, Shares Outstanding | 32,982,605 | ||
| ICFR Auditor Attestation Flag | false | ||
| Auditor Name | GRANT THORNTON LLP | ||
| Auditor Location | Tulsa, Oklahoma | ||
| Auditor Firm ID | 248 |
