XML 29 R31.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Related Party (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2019
Related Party [Abstract] |
Schedule of Related Party Transactions [Table Text Block] | The payments (receipts) with related parties for the years ended December 31, 2019, 2018, and 2017 were as follows:
| 2019 |  | 2018 |  | 2017
| (in thousands) |  |  |  |
Receipts for trailer sales | $ | — |  |  | $ | — |  |  | $ | (12) |
Payments for parts and services | 310 |  |  | 551 |  |  | 650 |
Terminal lease payments | — |  |  | 713 |  |  | 1,625 |
| $ | 310 |  |  | $ | 1,264 |  |  | $ | 2,263 |

X
- Definition Related Party [Abstract] + References No definition available. + Details
Name: | htld_RelatedPartyAbstract
Namespace Prefix: | htld_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of related party transactions. Examples of related party transactions include, but are not limited to, transactions between (a) a parent company and its subsidiary; (b) subsidiaries of a common parent; (c) and entity and its principal owners and (d) affiliates. + References No definition available. + Details
Name: | us-gaap_ScheduleOfRelatedPartyTransactionsTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration