XML 26 R25.htm IDEA: XBRL DOCUMENT
v3.20.1

Stock-Based Compensation (Tables) | 3 Months Ended
--- | ---
Mar. 31, 2020
Stock-Based Compensation [Abstract] |
Disclosure of restricted stock award activity | The following tables summarize our restricted stock award activity for the three months ended March 31, 2020 and 2019.
| Three Months Ended March 31, 2020 |  |
| Number of Shares of Restricted Stock Awards (in thousands) |  | Weighted Average Grant Date Fair Value
Unvested at beginning of period |  | 52.1 |  |  | $ | 20.55 |
Granted |  | 60.2 |  |  | 20.84 |
Vested |  | (38.0) |  |  | 20.86 |
Forfeited |  | (0.5) |  |  | 19.32 |
Outstanding (unvested) at end of period |  | 73.8 |  |  | $ | 20.66 |
| Three Months Ended March 31, 2019 |  |
| Number of Shares of Restricted Stock Awards (in thousands) |  | Weighted Average Grant Date Fair Value
Unvested at beginning of period |  | 26.5 |  |  | $ | 21.31 |
Granted |  | 12.5 |  |  | 20.04 |
Vested |  | (18.5) |  |  | 21.09 |
Forfeited |  | (0.5) |  |  | 17.11 |
Outstanding (unvested) at end of period |  | 20.0 |  |  | $ | 20.82 |

X
- Definition Stock-Based Compensation [Abstract] + References No definition available. + Details
Name: | htld_StockBasedCompensationAbstract
Namespace Prefix: | htld_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Tabular disclosure of share-based payment arrangement. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5047-113901 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=116856206&loc=d3e5070-113901 + Details
Name: | us-gaap_DisclosureOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTextBlock
Namespace Prefix: | us-gaap_
Data Type: | nonnum:textBlockItemType
Balance Type: | na
Period Type: | duration