SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)		12 Months Ended
Oct. 01, 2020	Dec. 31, 2020
Accounting Policies [Abstract]
Basis of Consolidation		The consolidated financial statements reflect the accounts of the Company and its wholly-owned and majority-owned subsidiaries. All significant intercompany profits, transactions, and balances have been eliminated in consolidation.
Reclassifications		Certain prior period amounts have been reclassified to conform to the current year presentation.
Use of Estimates		The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that directly affect the amounts reported in its consolidated financial statements and accompanying notes. Actual results could differ from these estimates.
Cash and Cash Equivalents		Cash and cash equivalents include all highly liquid investments with a maturity of three months or less at the time of purchase.
Accounts Receivable		Accounts receivable are shown net of expected losses and primarily include trade receivables. The Company records expected losses for customers based upon a variety of factors including the Company’s historical collection experience, the length of time the account has been outstanding and the financial condition of the customer. If the circumstances related to specific customers were to change, the Company’s estimates of expected losses with respect to the collectability of the related accounts could be further adjusted. The Company’s policy is to write-off receivables when they are determined to be uncollectible. Expected losses are charged to Selling and General and administrative expenses in the Consolidated Statements of Operations.
Inventories		Inventories are stated at the lower of cost, determined on either the first-in, first-out or average cost method, or net realizable value. The cost of manufactured inventory includes raw material, labor and overhead.
Prepaid Expenses and Other		Chassis converter pool agreements represent chassis transferred to the Company on a restricted basis by the manufacturer, who retains the sole authority to authorize commencement of work on the chassis and to make certain other decisions with respect to the chassis including the terms and pricing of sales to the manufacturer’s dealers. Assets held for sale are related to unused land parcels. Insurance premiums and maintenance agreements are charged to expense over the contractual life, which is generally one year or less. Other items primarily consist of the Company’s commodity swap contracts that are in an asset position, contract assets related to contracts for which the Company recognizes revenue on an over time basis, and investments held by the Company’s captive insurance subsidiary.
Property, Plant and Equipment		Property, plant and equipment are recorded at cost, net of accumulated depreciation. Maintenance and repairs are charged to expense as incurred, while expenditures that extend the useful life of an asset are capitalized. Depreciation is recorded using the straight-line method over the estimated useful lives of the depreciable assets. The estimated useful lives are up to 33 years for buildings and building improvements and range from three to ten years for machinery and equipment.
Goodwill	Goodwill represents the excess purchase price over fair value of the net assets acquired. The Company determines its reporting units at the individual operating segment level, or one level below, when there is discrete financial information available that is regularly reviewed by segment management for evaluating operating results. The Company reviews goodwill for impairment, at the reporting unit level, annually on October 1 and whenever events or changes in circumstances indicate its carrying value may not be recoverable. In accordance with ASC 350, Intangibles - Goodwill and Other, goodwill is reviewed for impairment utilizing either a qualitative assessment or a quantitative process. The Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. An entity has an unconditional option to bypass the qualitative assessment in any period and proceed directly to performing the quantitative impairment test, which is the option the Company has historically chosen. For reporting units in which the Company performs the quantitative analysis, the Company compares the carrying value, including goodwill, of each reporting unit with its estimated fair value. If the fair value of the reporting unit exceeds its carrying value, the goodwill is not considered impaired. If the carrying value is greater than the fair value, the difference is recognized as an impairment loss charged to the reporting unit. After an impairment loss is recognized, the adjusted carrying amount of goodwill shall be its new accounting basis. The Company exercised its unconditional option to bypass the qualitative assessment of goodwill for all of its reporting units and instead prepared a quantitative assessment to estimate the fair value of each reporting unit at the annual testing date of October 1, 2020 utilizing a combination of the income approach and the market approach, weighted equally. Based on the quantitative assessment performed, all of the Company’s reporting units exceeded their carrying values; as such, there was no goodwill impairment as a result of the 2020 annual goodwill impairment test.
Long-Lived Assets		Long-lived assets, consisting primarily of intangible assets and property, plant and equipment, are reviewed for impairment whenever facts and circumstances indicate that the carrying amount may not be recoverable. Specifically, this process involves comparing an asset’s carrying value to the estimated undiscounted future cash flows the asset is expected to generate over its remaining life. If this process were to result in the conclusion that the carrying value of a long-lived asset would not be recoverable, a write-down of the asset to fair value would be recorded through a charge to operations. Fair value is determined based upon discounted cash flows or appraisals as appropriate.
Other Assets		The Company capitalizes the cost of computer software developed or obtained for internal use. Capitalized software is amortized using the straight-line method over three to seven years.
Warranties		The Company offers a limited warranty for its products with a coverage period that ranges between one and five years, except that the coverage period for DuraPlate® trailer panels is ten years. The Company passes through component manufacturers’ warranties to our customers. The Company’s policy is to accrue the estimated cost of warranty coverage at the time of the sale.
Self Insured Liabilities		The Company is self-insured up to specified limits for medical and workers’ compensation coverage. The self-insurance reserves have been recorded to reflect the undiscounted estimated liabilities, including claims incurred but not reported, as well as catastrophic claims as appropriate.
Income Taxes		The Company determines its provision or benefit for income taxes under the asset and liability method. The asset and liability method measures the expected tax impact at current enacted rates of future taxable income or deductions resulting from differences in the tax and financial reporting basis of assets and liabilities reflected in the Consolidated Balance Sheets. Future tax benefits of tax losses and credit carryforwards are recognized as deferred tax assets. Deferred tax assets are reduced by a valuation allowance to the extent management determines that it is more-likely-than-not the Company would not realize the value of these assets.The Company accounts for income tax contingencies by prescribing a “more-likely-than-not” recognition threshold that a tax position is required to meet before being recognized in the financial statements.
Used Trailer Trade Commitments		The Company may accept trade-in of used trailers when a customer enters into a contract to purchase a new trailer. However, in the contracts for the sale of the new trailers, there is no commitment to repurchase that trailer or a similar trailer in the future. As of December 31, 2020, the Company had no outstanding trade commitments and $3.5 million outstanding trade commitments as of December 31, 2019. On occasion, the amount of the trade allowance provided for in the used trailer commitments, or cost, may exceed the net realizable value of the underlying used trailer. In these instances, the Company’s policy is to recognize the loss related to these commitments at the time the new trailer revenue is recognized. Net realizable value of used trailers is measured considering market sales data for comparable types of trailers.
Concentration of Credit Risk		Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash, cash equivalents, and customer receivables. We place our cash and cash equivalents with high quality financial institutions. Generally, we do not require collateral or other security to support customer receivables.
Research and Development		Research and development expenses are charged to Cost of sales and General and administrative expenses in the Consolidated Statements of Operations as incurred
New Accounting Pronouncements		In June 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standard Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses,” which introduced new guidance for an approach based on expected losses to estimate credit losses on certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. Instruments in scope include loans, held-to-maturity debt securities, and net investments in leases as well as reinsurance and trade receivables. In November 2018, the FASB issued ASU 2018-19, which clarifies that operating lease receivables are outside the scope of the new standard. The Company adopted the standard using the modified retrospective approach as required on January 1, 2020. The adoption of the new credit losses model did not have a material impact on the Company’s consolidated financial statements.
Revenue Recognition		The Company recognizes revenue from the sale of its products when obligations under the terms of a contract with our customers are satisfied; this occurs with the transfer of control of our products and replacement parts or throughout the completion of service work. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring promised goods or services to a customer and excludes all taxes collected from the customer. Shipping and handling fees are included in Net sales and the associated costs included in Cost of sales in the Consolidated Statements of Operations. For shipping and handling costs that take place after the transfer of control, the Company is applying the practical expedient and treating it as a fulfillment cost. Incidental items that are immaterial in the context of the contract are recognized as expense. For performance obligations satisfied over time, which include certain equipment-related sales within our Diversified Products reportable segment that have no alternative use and contain an enforceable right to payment, as well as service work whereby the customer simultaneously receives and consumes the benefits provided, the Company recognizes revenue on the basis of the Company’s efforts or inputs to the satisfaction of these performance obligations, measured by actual total cost incurred to the total estimated costs for each project. Total revenue recognized over time was not material to the consolidated financial statements for all periods presented. The Company has identified three separate and distinct performance obligations: (1) the sale of a trailer or equipment, (2) the sale of replacement parts, and (3) service work. For trailer, truck body, equipment, and replacement part sales, control is transferred and revenue is recognized from the sale upon shipment to or pick up by the customer in accordance with the contract terms. The Company does not have any material extended payment terms as payment is received shortly after the point of sale. Accounts receivable are recorded when the right to consideration becomes unconditional. The Company does have customers who pay for the product prior to the transfer of control which is recorded as customer deposits in Other accrued liabilities as shown in Note 8. Customer deposits are recognized as revenue when the Company performs its obligations under the contract and transfers control of the product.

SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)

12 Months Ended

Oct. 01, 2020

Dec. 31, 2020

The consolidated financial statements reflect the accounts of the Company and its wholly-owned and majority-owned subsidiaries. All significant intercompany profits, transactions, and balances have been eliminated in consolidation.

Reclassifications

Certain prior period amounts have been reclassified to conform to the current year presentation.

Use of Estimates

The preparation of consolidated financial statements in conformity with U.S. generally accepted accounting principles requires management to make estimates and assumptions that directly affect the amounts reported in its consolidated financial statements and accompanying notes. Actual results could differ from these estimates.

Cash and Cash Equivalents

Cash and cash equivalents include all highly liquid investments with a maturity of three months or less at the time of purchase.

Accounts Receivable

Accounts receivable are shown net of expected losses and primarily include trade receivables. The Company records expected losses for customers based upon a variety of factors including the Company’s historical collection experience, the length of time the account has been outstanding and the financial condition of the customer. If the circumstances related to specific customers were to change, the Company’s estimates of expected losses with respect to the collectability of the related accounts could be further adjusted. The Company’s policy is to write-off receivables when they are determined to be uncollectible. Expected losses are charged to Selling and General and administrative expenses in the Consolidated Statements of Operations.

Inventories

Inventories are stated at the lower of cost, determined on either the first-in, first-out or average cost method, or net realizable value. The cost of manufactured inventory includes raw material, labor and overhead.

Prepaid Expenses and Other

Chassis converter pool agreements represent chassis transferred to the Company on a restricted basis by the manufacturer, who retains the sole authority to authorize commencement of work on the chassis and to make certain other decisions with respect to the chassis including the terms and pricing of sales to the manufacturer’s dealers. Assets held for sale are related to unused land parcels. Insurance premiums and maintenance agreements are charged to expense over the contractual life, which is generally one year or less. Other items primarily consist of the Company’s commodity swap contracts that are in an asset position, contract assets related to contracts for which the Company recognizes revenue on an over time basis, and investments held by the Company’s captive insurance subsidiary.

Property, Plant and Equipment

Property, plant and equipment are recorded at cost, net of accumulated depreciation. Maintenance and repairs are charged to expense as incurred, while expenditures that extend the useful life of an asset are capitalized. Depreciation is recorded using the straight-line method over the estimated useful lives of the depreciable assets. The estimated useful lives are up to 33 years for buildings and building improvements and range from three to ten years for machinery and equipment.

Goodwill

Goodwill represents the excess purchase price over fair value of the net assets acquired. The Company determines its reporting units at the individual operating segment level, or one level below, when there is discrete financial information available that is regularly reviewed by segment management for evaluating operating results. The Company reviews goodwill for impairment, at the reporting unit level, annually on October 1 and whenever events or changes in circumstances indicate its carrying value may not be recoverable. In accordance with ASC 350, Intangibles - Goodwill and Other, goodwill is reviewed for impairment utilizing either a qualitative assessment or a quantitative process.

The Company has the option to first assess qualitative factors to determine whether the existence of events or circumstances leads to a determination that it is more likely than not that the fair value of a reporting unit is less than its carrying amount. An entity has an unconditional option to bypass the qualitative assessment in any period and proceed directly to performing the quantitative impairment test, which is the option the Company has historically chosen.

For reporting units in which the Company performs the quantitative analysis, the Company compares the carrying value, including goodwill, of each reporting unit with its estimated fair value. If the fair value of the reporting unit exceeds its carrying value, the goodwill is not considered impaired. If the carrying value is greater than the fair value, the difference is recognized as an impairment loss charged to the reporting unit. After an impairment loss is recognized, the adjusted carrying amount of goodwill shall be its new accounting basis.

The Company exercised its unconditional option to bypass the qualitative assessment of goodwill for all of its reporting units and instead prepared a quantitative assessment to estimate the fair value of each reporting unit at the annual testing date of October 1, 2020 utilizing a combination of the income approach and the market approach, weighted equally. Based on the quantitative assessment performed, all of the Company’s reporting units exceeded their carrying values; as such, there was no goodwill impairment as a result of the 2020 annual goodwill impairment test.

Long-Lived Assets

Long-lived assets, consisting primarily of intangible assets and property, plant and equipment, are reviewed for impairment whenever facts and circumstances indicate that the carrying amount may not be recoverable. Specifically, this process involves comparing an asset’s carrying value to the estimated undiscounted future cash flows the asset is expected to generate over its remaining life. If this process were to result in the conclusion that the carrying value of a long-lived asset would not be recoverable, a write-down of the asset to fair value would be recorded through a charge to operations. Fair value is determined based upon discounted cash flows or appraisals as appropriate.

Other Assets

The Company capitalizes the cost of computer software developed or obtained for internal use. Capitalized software is amortized using the straight-line method over three to seven years.

Warranties

The Company offers a limited warranty for its products with a coverage period that ranges between one and five years, except that the coverage period for DuraPlate® trailer panels is ten years. The Company passes through component manufacturers’ warranties to our customers. The Company’s policy is to accrue the estimated cost of warranty coverage at the time of the sale.

Self Insured Liabilities

The Company is self-insured up to specified limits for medical and workers’ compensation coverage. The self-insurance reserves have been recorded to reflect the undiscounted estimated liabilities, including claims incurred but not reported, as well as catastrophic claims as appropriate.

Income Taxes

The Company determines its provision or benefit for income taxes under the asset and liability method. The asset and liability method measures the expected tax impact at current enacted rates of future taxable income or deductions resulting from differences in the tax and financial reporting basis of assets and liabilities reflected in the Consolidated Balance Sheets. Future tax benefits of tax losses and credit carryforwards are recognized as deferred tax assets. Deferred tax assets are reduced by a valuation allowance to the extent management determines that it is more-likely-than-not the Company would not realize the value of these assets.The Company accounts for income tax contingencies by prescribing a “more-likely-than-not” recognition threshold that a tax position is required to meet before being recognized in the financial statements.

Used Trailer Trade Commitments

The Company may accept trade-in of used trailers when a customer enters into a contract to purchase a new trailer. However, in the contracts for the sale of the new trailers, there is no commitment to repurchase that trailer or a similar trailer in the future. As of December 31, 2020, the Company had no outstanding trade commitments and $3.5 million outstanding trade commitments as of December 31, 2019. On occasion, the amount of the trade allowance provided for in the used trailer commitments, or cost, may exceed the net realizable value of the underlying used trailer. In these instances, the Company’s policy is to recognize the loss related to these commitments at the time the new trailer revenue is recognized. Net realizable value of used trailers is measured considering market sales data for comparable types of trailers.

Concentration of Credit Risk

Financial instruments that potentially subject us to significant concentrations of credit risk consist principally of cash, cash equivalents, and customer receivables. We place our cash and cash equivalents with high quality financial institutions. Generally, we do not require collateral or other security to support customer receivables.

Research and Development

Research and development expenses are charged to Cost of sales and General and administrative expenses in the Consolidated Statements of Operations as incurred

New Accounting Pronouncements

In June 2016, the Financial Accounting Standards Board (the “FASB”) issued Accounting Standard Update (“ASU”) 2016-13, “Financial Instruments - Credit Losses,” which introduced new guidance for an approach based on expected losses to estimate credit losses on certain types of financial instruments. It also modifies the impairment model for available-for-sale debt securities and provides for a simplified accounting model for purchased financial assets with credit deterioration since their origination. Instruments in scope include loans, held-to-maturity debt securities, and net investments in leases as well as reinsurance and trade receivables. In November 2018, the FASB issued ASU 2018-19, which clarifies that operating lease receivables are outside the scope of the new standard. The Company adopted the standard using the modified retrospective approach as required on January 1, 2020. The adoption of the new credit losses model did not have a material impact on the Company’s consolidated financial statements.

Revenue Recognition

The Company recognizes revenue from the sale of its products when obligations under the terms of a contract with our customers are satisfied; this occurs with the transfer of control of our products and replacement parts or throughout the completion of service work. Revenue is measured as the amount of consideration we expect to receive in exchange for transferring promised goods or services to a customer and excludes all taxes collected from the customer. Shipping and handling fees are included in Net sales and the associated costs included in Cost of sales in the Consolidated Statements of Operations. For shipping and handling costs that take place after the transfer of control, the Company is applying the practical expedient and treating it as a fulfillment cost. Incidental items that are immaterial in the context of the contract are recognized as expense. For performance obligations satisfied over time, which include certain equipment-related sales within our Diversified Products reportable segment that have no alternative use and contain an enforceable right to payment, as well as service work whereby the customer simultaneously receives and consumes the benefits provided, the Company recognizes revenue on the basis of the Company’s efforts or inputs to the satisfaction of these performance obligations, measured by actual total cost incurred to the total estimated costs for each project. Total revenue recognized over time was not material to the consolidated financial statements for all periods presented.

The Company has identified three separate and distinct performance obligations: (1) the sale of a trailer or equipment, (2) the sale of replacement parts, and (3) service work. For trailer, truck body, equipment, and replacement part sales, control is transferred and revenue is recognized from the sale upon shipment to or pick up by the customer in accordance with the contract terms. The Company does not have any material extended payment terms as payment is received shortly after the point of sale. Accounts receivable are recorded when the right to consideration becomes unconditional. The Company does have customers who pay for the product prior to the transfer of control which is recorded as customer deposits in Other accrued liabilities as shown in Note 8. Customer deposits are recognized as revenue when the Company performs its obligations under the contract and transfers control of the product.