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| 0000799233-17-000012-index.html | 2017-02-28 12:41:50 | |
| 0000799233-17-000012.txt | 2017-02-28 12:41:50 | |
 0000799233-17-000012-xbrl.zip | 183779 | 2017-02-28 12:41:50 |
| a2016exhibitno21.htm | 7378 | 2017-02-28 12:41:50 |
| exhibit3112016q4.htm | 23558 | 2017-02-28 12:41:50 |
| exhibit3122016q4.htm | 24705 | 2017-02-28 12:41:50 |
| exhibit3212016q4.htm | 9722 | 2017-02-28 12:41:50 |
| exhibit3222016q4.htm | 10609 | 2017-02-28 12:41:50 |
| FilingSummary.xml | 36414 | 2017-02-28 12:41:50 |
| Financial_Report.xlsx | 79881 | 2017-02-28 12:41:50 |
| htld-20161231.xml | 1167365 | 2017-02-28 12:41:50 |
| htld-20161231.xsd | 49053 | 2017-02-28 12:41:50 |
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| htld-20161231_def.xml | 218595 | 2017-02-28 12:41:50 |
| htld-20161231_lab.xml | 622607 | 2017-02-28 12:41:50 |
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| htld201610k.htm | 1589254 | 2017-02-28 12:41:50 |
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| report.css | 2767 | 2017-02-28 12:41:50 |
| Show.js | 1410 | 2017-02-28 12:41:50 |