XML 47 R33.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Prepaid Tires, Property, Equipment and Depreciation (Details) - USD ($) $ in Thousands | 9 Months Ended | 12 Months Ended
--- | --- | ---
Sep. 30, 2017 | Sep. 30, 2016 | Dec. 31, 2016
Property, Plant and Equipment [Line Items] |  |  |
Amortization Period of Tires | 2 years |  |
Increase (Decrease) in Restricted Cash and Investments | $ 6,313 | $ 1,803 | $ 200
Tractors [Member] |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Property, Plant, and Equipment, Salvage Value | 15 |  |
Trailers [Member] |  |  |
Property, Plant and Equipment [Line Items] |  |  |
Property, Plant, and Equipment, Salvage Value | $ 4 |  |

X
- Definition Amortization Period of Tires + References No definition available. + Details
Name: | htld_AmortizationPeriodOfTires
Namespace Prefix: | htld_
Data Type: | us-types:durationStringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The net cash inflow or outflow during the period for the aggregate increase (decrease) associated with funds and investments that are not available for withdrawal or use (such as assets held in escrow or contractually limited as to use or disposition) and are associated with underlying transactions that are classified as investing activities. + References No definition available. + Details
Name: | us-gaap_IncreaseDecreaseInRestrictedCashAndInvestments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The estimated or actual value of the asset at the end of its useful life or when it is no longer serviceable (cannot be used for its original purpose). + References No definition available. + Details
Name: | us-gaap_PropertyPlantAndEquipmentSalvageValue
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=htld_TractorsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_PropertyPlantAndEquipmentByTypeAxis=htld_TrailersMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |