Fair value of revenue equipment traded

No definition available.

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Period Type:	duration

- Definition

Payments for parts and services

+ References

No definition available.

+ Details

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Balance Type:	debit
Period Type:	duration

- Definition

Costs of sales and operating expenses for the period incurred from transactions with related parties.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 220
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.2)
-URI http://asc.fasb.org/extlink&oid=115205541&loc=SL114868664-224227

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Balance Type:	debit
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- Definition

Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 235
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.4-08.(k)(1))
-URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 850
-SubTopic 10
-Section 50
-Paragraph 1
-Subparagraph (d)
-URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.19(a))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Amount of rent expense incurred for leased assets, including but not limited to, furniture and equipment, that is not directly or indirectly associated with the manufacture, sale or creation of a product or product line.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- 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

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Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Details

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- Details

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Balance Type:
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- Details

Name:	us-gaap_PropertyPlantAndEquipmentByTypeAxis=htld_TrailersMember
Namespace Prefix:
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Related Party (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
Related Party (Details) - USD ($) $ in Thousands	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017	Dec. 31, 2017
Related Party Transaction [Line Items]
Due to Related Parties, Current	$ 100		$ 100		$ 100
Operating Leases, Rent Expense	900	$ 3,800	4,500	$ 3,800
Costs and Expenses, Related Party	316	593	1,058	1,624
Related Party
Related Party Transaction [Line Items]
Payments for parts and services	65	172	346	409
Terminal Facilities
Related Party Transaction [Line Items]
Operating Leases, Rent Expense	1,200	1,500	3,800	2,500
Terminal Facilities \| Related Party
Related Party Transaction [Line Items]
Operating Leases, Rent Expense	$ 251	$ 421	712	1,227
Trailers [Member] \| Related Party
Related Party Transaction [Line Items]
Fair value of revenue equipment traded			$ 0	$ (12)