XML 38 R28.htm IDEA: XBRL DOCUMENT
v2.4.1.9

Long-Term Debt (Tables) | 12 Months Ended
--- | ---
Dec. 31, 2014
Line of Credit, Long-Term Debt [Abstract] |
Schedule of Maturities of Long-term Debt [Table Text Block] | Long term debt consisted of the following at December 31 (in thousands):
|  | December 31, 2014 |  | December 31, 2013
Long-term debt |  | $ | 24,600 |  |  | $ | 75,000 |

X
- Details
Name: | htld_LineofCreditLongTermDebtAbstract
Namespace Prefix: | htld_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of the combined aggregate amount of maturities and sinking fund requirements for all long-term borrowings for each of the five years following the date of the latest balance sheet date presented. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=6802200&loc=d3e1835-112601 + Details
Name: | us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration