XML 12 R2.htm IDEA: XBRL DOCUMENT
v3.23.1

Pay vs Performance Disclosure - USD ($) | 12 Months Ended
--- | ---
Dec. 31, 2022 | Dec. 31, 2021 | Dec. 31, 2020
Pay vs Performance Disclosure [Table] |  |  |
Pay vs Performance [Table Text Block] | The following table presents information about our Named Executive Officers’ pay and Company performance for each of the Company’s three most recently completed fiscal years.
PAY VERSUS PERFORMANCE TABLE
|  |  |  |  | Value of Initial Fixed $100 Investment Based On: |  |
Year | Summary Compensation Table Total for CEO ($) (1) | Compensation Actually Paid to CEO($) (1)(2) | Average Summary Compensation Table Total for Non-CEO NEOs ($) (3) | Average Compensation Actually Paid to Non-CEO NEOs ($) (2)(3) | Total Shareholder Return ($) | Peer Group Total Shareholder Return ($) (4) | Net Income ($) (in 000’s) | Operating Income ($) (in 000’s)
2022 | 5,460,198 |  | 2,465,428 |  | 1,094,807 |  | 701,308 |  | 115 |  | 176 |  | 245,580 |  | 323,076 |
2021 | 5,314,351 |  | 8,798,833 |  | 1,133,218 |  | 1,587,300 |  | 134 |  | 215 |  | 261,478 |  | 309,146 |
2020 | 4,810,029 |  | 6,822,876 |  | 1,102,850 |  | 1,423,523 |  | 109 |  | 132 |  | 169,078 |  | 227,438 |
(1) | Represents compensation of Mr. Leathers for all periods presented.
(2) | SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine “compensation actually paid.” The Reconciliation of Compensation Actually Paid Adjustments table below details the applicable adjustments that were made to determine “compensation actually paid” (all amounts are averages for the non-CEO NEOs).
(3) | Compensation of Messrs. Steele, Nordlund, Schelble, and Johnson are included in the average compensation calculations for all periods presented.
(4) | Our Peer Group includes companies similar to us in the transportation industry and has the following companies: ArcBest; Covenant Logistics Group; Forward Air; Heartland Express; Hub Group; JB Hunt; Knight-Swift Transportation; Landstar System; Marten Transport; Old Dominion Freight Line; Saia; Schneider National; US Xpress; and Yellow Corporation.
Named Executive Officers, Footnote [Text Block] | Represents compensation of Mr. Leathers for all periods presented.Compensation of Messrs. Steele, Nordlund, Schelble, and Johnson are included in the average compensation calculations for all periods presented. |  |
Peer Group Issuers, Footnote [Text Block] | Our Peer Group includes companies similar to us in the transportation industry and has the following companies: ArcBest; Covenant Logistics Group; Forward Air; Heartland Express; Hub Group; JB Hunt; Knight-Swift Transportation; Landstar System; Marten Transport; Old Dominion Freight Line; Saia; Schneider National; US Xpress; and Yellow Corporation. |  |
PEO Total Compensation Amount | $ 5,460,198 | $ 5,314,351 | $ 4,810,029
PEO Actually Paid Compensation Amount | $ 2,465,428 | 8,798,833 | 6,822,876
Adjustment To PEO Compensation, Footnote [Text Block] | SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine “compensation actually paid.” The Reconciliation of Compensation Actually Paid Adjustments table below details the applicable adjustments that were made to determine “compensation actually paid” (all amounts are averages for the non-CEO NEOs). The following table reconciles total compensation reported in the Summary Compensation Table to “compensation actually paid” for the CEO and non-CEO NEOs (averaged) over the last three years.
RECONCILIATION OF COMPENSATION ACTUALLY PAID ADJUSTMENTS
Year | Summary Compensation Table “Total” Column ($) | Subtract Summary Compensation Table “Stock Awards” Column ($) | Add Year End Fair Value of Unvested Equity Awards Granted in Year ($) | Add/ (Subtract) Year Over Year Change in Fair Value of Unvested Equity Awards Granted in Prior Years ($) | Add/ (Subtract) Year Over Year Change in Fair Value of Equity Awards Granted in Prior Years that Vested in Year ($) | Compensation Actually Paid ($)
CEO
2022 | 5,460,198 |  | (3,200,000) |  | 2,507,777 |  | (2,102,923) |  | (199,624) |  | 2,465,428 |
2021 | 5,314,351 |  | (2,800,000) |  | 4,741,960 |  | 1,288,523 |  | 253,999 |  | 8,798,833 |
2020 | 4,810,029 |  | (2,800,000) |  | 4,252,764 |  | 302,174 |  | 257,909 |  | 6,822,876 |
Non-CEO NEOs (Average)
2022 | 1,094,807 |  | (350,000) |  | 274,289 |  | (287,911) |  | (29,877) |  | 701,308 |
2021 | 1,133,218 |  | (312,500) |  | 529,187 |  | 195,957 |  | 41,438 |  | 1,587,300 |
2020 | 1,102,850 |  | (412,500) |  | 626,539 |  | 49,962 |  | 56,672 |  | 1,423,523 |
Non-PEO NEO Average Total Compensation Amount | $ 1,094,807 | 1,133,218 | 1,102,850
Non-PEO NEO Average Compensation Actually Paid Amount | $ 701,308 | 1,587,300 | 1,423,523
Adjustment to Non-PEO NEO Compensation Footnote [Text Block] | SEC rules require certain adjustments be made to the Summary Compensation Table totals to determine “compensation actually paid.” The Reconciliation of Compensation Actually Paid Adjustments table below details the applicable adjustments that were made to determine “compensation actually paid” (all amounts are averages for the non-CEO NEOs). The following table reconciles total compensation reported in the Summary Compensation Table to “compensation actually paid” for the CEO and non-CEO NEOs (averaged) over the last three years.
RECONCILIATION OF COMPENSATION ACTUALLY PAID ADJUSTMENTS
Year | Summary Compensation Table “Total” Column ($) | Subtract Summary Compensation Table “Stock Awards” Column ($) | Add Year End Fair Value of Unvested Equity Awards Granted in Year ($) | Add/ (Subtract) Year Over Year Change in Fair Value of Unvested Equity Awards Granted in Prior Years ($) | Add/ (Subtract) Year Over Year Change in Fair Value of Equity Awards Granted in Prior Years that Vested in Year ($) | Compensation Actually Paid ($)
CEO
2022 | 5,460,198 |  | (3,200,000) |  | 2,507,777 |  | (2,102,923) |  | (199,624) |  | 2,465,428 |
2021 | 5,314,351 |  | (2,800,000) |  | 4,741,960 |  | 1,288,523 |  | 253,999 |  | 8,798,833 |
2020 | 4,810,029 |  | (2,800,000) |  | 4,252,764 |  | 302,174 |  | 257,909 |  | 6,822,876 |
Non-CEO NEOs (Average)
2022 | 1,094,807 |  | (350,000) |  | 274,289 |  | (287,911) |  | (29,877) |  | 701,308 |
2021 | 1,133,218 |  | (312,500) |  | 529,187 |  | 195,957 |  | 41,438 |  | 1,587,300 |
2020 | 1,102,850 |  | (412,500) |  | 626,539 |  | 49,962 |  | 56,672 |  | 1,423,523 |
Compensation Actually Paid vs. Total Shareholder Return [Text Block] | The following graphs illustrate the relationships between each of the financial performance measures included in the Pay Versus Performance Table above and the compensation actually paid to the CEO and, on average, to non-CEO NEOs over the Company’s three most recently completed fiscal years. |  |
Compensation Actually Paid vs. Net Income [Text Block] |  |  |
Compensation Actually Paid vs. Company Selected Measure [Text Block] |  |  |
Total Shareholder Return Vs Peer Group [Text Block] | The following graphs illustrate the relationships between each of the financial performance measures included in the Pay Versus Performance Table above and the compensation actually paid to the CEO and, on average, to non-CEO NEOs over the Company’s three most recently completed fiscal years. |  |
Total Shareholder Return Amount | $ 115 | 134 | 109
Peer Group Total Shareholder Return Amount | 176 | 215 | 132
Net Income (Loss) | $ 245,580,000 | $ 261,478,000 | $ 169,078,000
Company Selected Measure Amount | 323,076,000 | 309,146,000 | 227,438,000
PEO Name | Mr. Leathers |  |
Measure [Axis]: 1 |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Measure Name | •Revenues, less fuel surcharge revenues |  |
Measure [Axis]: 2 |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Measure Name | •Operating income |  |
Measure [Axis]: 3 |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Measure Name | Diluted earnings per share |  |
PEO [Member] | Stock Awards Adjustment [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | $ (3,200,000) | $ (2,800,000) | $ (2,800,000)
PEO [Member] | Equity Awards Granted in Current Year, Fair Value Adjustment [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 2,507,777 | 4,741,960 | 4,252,764
PEO [Member] | Equity Awards Adjustment, Unvested, Granted in Prior Years [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (2,102,923) | 1,288,523 | 302,174
PEO [Member] | Equity Awards Adjustment, Vested, Granted in Prior Years [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (199,624) | 253,999 | 257,909
Non-PEO NEO [Member] | Stock Awards Adjustment [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (350,000) | (312,500) | (412,500)
Non-PEO NEO [Member] | Equity Awards Granted in Current Year, Fair Value Adjustment [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | 274,289 | 529,187 | 626,539
Non-PEO NEO [Member] | Equity Awards Adjustment, Unvested, Granted in Prior Years [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | (287,911) | 195,957 | 49,962
Non-PEO NEO [Member] | Equity Awards Adjustment, Vested, Granted in Prior Years [Member] |  |  |
Pay vs Performance Disclosure [Table] |  |  |
Adjustment to Compensation Amount | $ (29,877) | $ 41,438 | $ 56,672

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToNonPeoNeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_AdjToPeoCompFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_CoSelectedMeasureAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:decimalItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iii + Details
Name: | ecd_CompActuallyPaidVsCoSelectedMeasureTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph ii + Details
Name: | ecd_CompActuallyPaidVsNetIncomeTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph i + Details
Name: | ecd_CompActuallyPaidVsTotalShareholderRtnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph vi + Details
Name: | ecd_MeasureName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_NamedExecutiveOfficersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_NonPeoNeoAvgCompActuallyPaidAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_NonPeoNeoAvgTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupIssuersFnTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_PeerGroupTotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iii + Details
Name: | ecd_PeoActuallyPaidCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 3 + Details
Name: | ecd_PeoName
Namespace Prefix: | ecd_
Data Type: | xbrli:normalizedStringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph ii + Details
Name: | ecd_PeoTotalCompAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTable
Namespace Prefix: | ecd_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 1 + Details
Name: | ecd_PvpTableTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 2 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnAmt
Namespace Prefix: | ecd_
Data Type: | xbrli:monetaryItemType
Balance Type: | na
Period Type: | duration

X
- References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-K -Number 229 -Section 402 -Subsection v -Paragraph 5 -Subparagraph iv + Details
Name: | ecd_TotalShareholderRtnVsPeerGroupTextBlock
Namespace Prefix: | ecd_
Data Type: | dtr-types:textBlockItemType
Balance Type: | na
Period Type: | duration

X
- Definition The portion of profit or loss for the period, net of income taxes, which is attributable to the parent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-04(22)) -URI https://asc.fasb.org/extlink&oid=120399700&loc=SL114874048-224260 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 4 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22595-107794 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 220 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-04(18)) -URI https://asc.fasb.org/extlink&oid=120400993&loc=SL114874131-224263 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 815 -SubTopic 40 -Section 65 -Paragraph 1 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=126732423&loc=SL123482106-238011 Reference 6: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 50 -Paragraph 6 -URI https://asc.fasb.org/extlink&oid=124431353&loc=SL124452729-227067 Reference 7: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 8: 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(20)) -URI https://asc.fasb.org/extlink&oid=126953954&loc=SL114868664-224227 Reference 9: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 28 -URI https://asc.fasb.org/extlink&oid=126954810&loc=d3e3602-108585 Reference 10: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22499-107794 Reference 11: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 12: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 13: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 14: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(i)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 15: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 9 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22663-107794 Reference 16: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iv)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 17: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(4)(ii)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 18: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI https://asc.fasb.org/extlink&oid=123596393&loc=d3e14064-108612 Reference 19: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 3 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22583-107794 Reference 20: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08(g)(1)(ii)) -URI https://asc.fasb.org/extlink&oid=120395691&loc=d3e23780-122690 Reference 21: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 260 -SubTopic 10 -Section 45 -Paragraph 60B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126958026&loc=SL5780133-109256 Reference 22: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=114001798&loc=d3e33918-111571 Reference 23: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 8 -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22658-107794 Reference 24: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1A -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669619-108580 Reference 25: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 31 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8924-108599 Reference 26: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794 Reference 27: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 250 -SubTopic 10 -Section 50 -Paragraph 11 -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=124431687&loc=d3e22694-107794 Reference 28: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 205 -SubTopic 20 -Section 50 -Paragraph 7 -URI https://asc.fasb.org/extlink&oid=109222650&loc=SL51721683-107760 Reference 29: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 220 -SubTopic 10 -Section 45 -Paragraph 1B -Subparagraph (a) -URI https://asc.fasb.org/extlink&oid=126968391&loc=SL7669625-108580 Reference 30: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 22 -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8736-108599 Reference 31: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1A -Subparagraph (SX 210.13-01(a)(5)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442526-122756 Reference 32: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(B)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 33: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 470 -SubTopic 10 -Section S99 -Paragraph 1B -Subparagraph (SX 210.13-02(a)(4)(iii)(A)) -URI https://asc.fasb.org/extlink&oid=126975872&loc=SL124442552-122756 Reference 34: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 30 -Subparagraph (b) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8906-108599 Reference 35: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 280 -SubTopic 10 -Section 50 -Paragraph 32 -Subparagraph (c) -URI https://asc.fasb.org/extlink&oid=126901519&loc=d3e8933-108599 + Details
Name: | us-gaap_NetIncomeLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Details
Name: | ecd_MeasureAxis=1
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=2
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_MeasureAxis=3
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_PeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=wern_StockAwardsAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=wern_EquityAwardsGrantedInCurrentYearFairValueAdjustmentMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=wern_EquityAwardsAdjustmentUnvestedGrantedInPriorYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_AdjToCompAxis=wern_EquityAwardsAdjustmentVestedGrantedInPriorYearsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | ecd_ExecutiveCategoryAxis=ecd_NonPeoNeoMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |