Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000799233-21-000034-index-headers.html | 2021-06-14 15:45:32 | |
| 0000799233-21-000034-index.html | 2021-06-14 15:45:32 | |
| 0000799233-21-000034.txt | 2021-06-14 15:45:32 | |
 0000799233-21-000034-xbrl.zip | 12115 | 2021-06-14 15:45:32 |
| FilingSummary.xml | 1670 | 2021-06-14 15:45:32 |
| Financial_Report.xlsx | 5693 | 2021-06-14 15:45:32 |
| htld-20210611.htm | 38661 | 2021-06-14 15:45:32 |
| htld-20210611.xsd | 2187 | 2021-06-14 15:45:32 |
| htld-20210611_htm.xml | 11087 | 2021-06-14 15:45:32 |
| htld-20210611_lab.xml | 24583 | 2021-06-14 15:45:32 |
| htld-20210611_pre.xml | 12763 | 2021-06-14 15:45:32 |
| MetaLinks.json | 17415 | 2021-06-14 15:45:32 |
| q22021dividendpressrelease.htm | 4413 | 2021-06-14 15:45:32 |
| R1.htm | 39670 | 2021-06-14 15:45:32 |
| report.css | 2767 | 2021-06-14 15:45:32 |
| Show.js | 1084 | 2021-06-14 15:45:32 |