XML 35 R21.htm IDEA: XBRL DOCUMENT
v3.24.0.1

Schedule II Valuation of Qualifying Accounts and Reserves | 12 Months Ended
--- | ---
Dec. 31, 2023
Schedule II Valuation and Qualifying Accounts and Reserves [Abstract] |
SEC Schedule, 12-09, Schedule of Valuation and Qualifying Accounts Disclosure [Text Block] |
SCHEDULE II VALUATION AND QUALIFYING ACCOUNTS AND RESERVES (In Thousands, Except Per Share Data)
|  |  |  | Column C |  |  |  |
Column A |  | Column B |  | Charges To |  | Column D |  | Column E
|  | Balance At |  | Cost |  |  |  |  |  | Balance
|  | Beginning |  | And |  | Other |  |  |  | At End
Description |  | of Period |  | Expense |  | Accounts |  | Deductions |  | of Period
Allowance for credit losses: |  |  |  |  |  |  |  |  |  |
Year ended December 31, 2023 |  | $ | 3,300 |  |  | $ | — |  |  | $ | — |  |  | $ | 600 |  |  | $ | 2,700 |
Year ended December 31, 2022 |  | 1,100 |  |  | — |  |  | 2,200 |  |  | — |  |  | 3,300 |
Year ended December 31, 2021 |  | 1,100 |  |  | — |  |  | — |  |  | — |  |  | 1,100 |
See accompanying Report of Independent Registered Public Accounting Firm.

X
- Definition Schedule II Valuation and Qualifying Accounts and Reserves [Abstract] + References No definition available. + Details
Name: | htld_ScheduleIiValuationAndQualifyingAccountsAndReservesAbstract
Namespace Prefix: | htld_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The entire disclosure for valuation and qualifying accounts and reserves. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Name Regulation S-X (SX) -Number 210 -Section 12 -Subsection 09 -Publisher SEC Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Topic 235 -SubTopic 10 -Name Accounting Standards Codification -Section S99 -Paragraph 4 -Subparagraph (SX 210.12-09) -Publisher FASB -URI https://asc.fasb.org//1943274/2147480678/235-10-S99-4 + Details
Name: | srt_ScheduleOfValuationAndQualifyingAccountsDisclosureTextBlock
Namespace Prefix: | srt_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration