Related Party (Details) (USD $)	3 Months Ended
Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Related Party Transaction [Line Items]
Due to Related Parties, Current	$ 800,000us-gaap_DueToRelatedPartiesCurrent		$ 100,000us-gaap_DueToRelatedPartiesCurrent
Receipts for tractor sales	0htld_FairValueOfRevenueEquipmentTraded	3,198,000htld_FairValueOfRevenueEquipmentTraded
Operating Leases, Rent Expense	1,100,000us-gaap_LeaseAndRentalExpense	2,300,000us-gaap_LeaseAndRentalExpense
Due from Related Parties, Current	2,500,000us-gaap_DueFromRelatedPartiesCurrent		0us-gaap_DueFromRelatedPartiesCurrent
Costs and Expenses, Related Party	(3,027,000)us-gaap_CostsAndExpensesRelatedParty	12,543,000us-gaap_CostsAndExpensesRelatedParty
Related Party
Related Party Transaction [Line Items]
Payments for tractor purchase	2,099,000	11,483,000
Receipts for tractor sales	(8,527,000)	(3,198,000)
Operating Leases, Rent Expense	1,085,000	1,830,000
Payments for parts and services	1,360,000	1,542,000
Administrative Services Revenue	0	(141,000)
Terminal Facilities
Related Party Transaction [Line Items]
Operating Leases, Rent Expense	1,000,000	1,100,000
Terminal Facilities \| Related Party
Related Party Transaction [Line Items]
Operating Leases, Rent Expense	$ 956,000	$ 1,027,000

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- Definition

Payments for parts and services

+ References

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- Definition

Amount of revenue from providing administrative services, including, but not limited to, accounting, tax, legal, regulatory filing, and share registration activities of managed funds and investment accounts of independent third parties and related and affiliated entities.

+ References

No definition available.

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- Definition

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

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.2)

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- Definition

The aggregate amount of receivables to be collected from related parties where one party can exercise control or significant influence over another party; including affiliates, owners or officers and their immediate families, pension trusts, and so forth, at the financial statement date. which are usually due within one year (or one business cycle).

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

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-Name Regulation S-X (SX)

-Number 210

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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://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

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-Subparagraph (SX 210.4-08.(k)(1))

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-Paragraph 1

-Subparagraph (SX 210.5-02.19(a))

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- 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.

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- Definition

The cash outflow for acquisition of machinery and equipment.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Glossary Investing Activities

-URI http://asc.fasb.org/extlink&oid=6516133

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