Parent Directory| Name | Size | Last Modified |
|---|---|---|
 0000799233-21-000019-index-headers.html | 2021-03-12 10:49:48 | |
| 0000799233-21-000019-index.html | 2021-03-12 10:49:48 | |
| 0000799233-21-000019.txt | 2021-03-12 10:49:48 | |
 0000799233-21-000019-xbrl.zip | 13305 | 2021-03-12 10:49:48 |
| FilingSummary.xml | 1747 | 2021-03-12 10:49:48 |
| Financial_Report.xlsx | 5481 | 2021-03-12 10:49:48 |
| htld-20210312.htm | 38669 | 2021-03-12 10:49:48 |
| htld-20210312.xsd | 2696 | 2021-03-12 10:49:48 |
| htld-20210312_cal.xml | 738 | 2021-03-12 10:49:48 |
| htld-20210312_def.xml | 1675 | 2021-03-12 10:49:48 |
| htld-20210312_htm.xml | 11090 | 2021-03-12 10:49:48 |
| htld-20210312_lab.xml | 24583 | 2021-03-12 10:49:48 |
| htld-20210312_pre.xml | 12763 | 2021-03-12 10:49:48 |
| MetaLinks.json | 17584 | 2021-03-12 10:49:48 |
| q12021dividendpressrelease.htm | 4444 | 2021-03-12 10:49:48 |
| R1.htm | 39673 | 2021-03-12 10:49:48 |
| report.css | 2767 | 2021-03-12 10:49:48 |
| Show.js | 1085 | 2021-03-12 10:49:48 |