XML 70 R57.htm IDEA: XBRL DOCUMENT
v3.22.4

Profit Sharing Plan and Retirement Plan (Details) - USD ($) $ in Millions | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Profit Sharing Plan and Retirement Plan [Abstract] |  |  |
Defined Contribution Plan, Cost | $ 2.2 | $ 2.2 | $ 2.3

X
- Definition Profit Sharing Plan and Retirement Plan [Abstract] + References No definition available. + Details
Name: | htld_ProfitSharingPlanAndRetirementPlanAbstract
Namespace Prefix: | htld_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of cost for defined contribution plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 70 -Section 50 -Paragraph 1 -URI https://asc.fasb.org/extlink&oid=49170846&loc=d3e28014-114942 + Details
Name: | us-gaap_DefinedContributionPlanCostRecognized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration