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Secured Credit Facility and Other Debt - Narrative (Details) |  |  |  | 12 Months Ended |
--- | --- | --- | --- | --- | ---
Apr. 03, 2020 USD ($) | Apr. 03, 2019 USD ($) | Apr. 03, 2017 USD ($) | Dec. 31, 2017 USD ($) | Dec. 31, 2016 USD ($) | Dec. 31, 2015 USD ($) | May 31, 2015 USD ($)
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notes and deferred payments to sellers |  |  |  | $ 11,588,000 | $ 0 | $ 0 |
Total loans, Net |  |  |  | 90,138,000 | 5,394,000 |  |
Debt extinguishment |  |  |  | 800,000 |  | 200,000 |
Interest expense |  |  |  | 9,800,000 | 2,628,000 | $ 3,012,000 |
Revolving Credit Facility |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Borrowings on equipment based facility |  |  |  | 0 | 0 |  |
Loan and Security Agreement | Senior Secured Term Loans | Wilmington Trust, National Association |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, face amount |  |  | $ 85,000,000 |  |  |  |
Loan prepayment offer required to make quarterly percentage |  |  | 75.00% |  |  |  |
Debt instrument financial covenants maximum ratio of secured indebtedness to EBITDA, period one |  |  | 3.10 |  |  |  |
Debt instrument financial covenants maximum ratio of secured indebtedness to EBITDA, period two |  |  | 1.80 |  |  |  |
Debt instrument financial covenants, minimum daily cash collateral, period two |  |  | $ 15,000,000 |  |  |  |
Debt instrument financial covenants, minimum daily cash collateral, potential additional period |  |  | 18,000,000 |  |  |  |
Debt instrument, financial covenants minimum rolling four quarter gross margin in contract backlog, period one |  |  | 60,000,000 |  |  |  |
Debt instrument, financial covenants minimum rolling four quarter gross margin in contract backlog period two |  |  | 70,000,000 |  |  |  |
Debt instrument, financial covenants, maximum incurrence of net capital expenditures during each of four consecutive fiscal quarters |  |  | 15,000,000 |  |  |  |
Debt instrument, financial covenants, minimum bonding capacity |  |  | 1,000,000,000 |  |  |  |
Debt instrument financial covenants minimum EBITDA during each four consecutive fiscal quarters |  |  | $ 12,000,000 |  |  |  |
Debt issuance costs |  |  |  | $ 10,400,000 |  |  |
Debt instrument, term |  |  |  | 5 years |  |  |
Amortization of debt issuance costs |  |  |  | $ 1,600,000 |  |  |
Loan and Security Agreement | Senior Secured Term Loans | London Interbank Offered Rate (LIBOR) | Wilmington Trust, National Association |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Basis spread on variable rate |  |  | 8.75% |  |  |  |
Notes Payable for Transportation and Construction Equipment |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Notes payable |  |  |  | 1,600,000 | 2,700,000 |  |
Equipment-based Facility |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Remaining borrowing capacity |  |  |  |  | 20,000,000 |  |
Line of credit, maximum borrowing capacity |  |  |  |  |  |  | $ 40,000,000
Equipment-based Facility | Senior Secured Term Loans | Nations |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt issuance costs |  |  |  | 8,812,000 | 803,000 |  |
Total loans, Net |  |  |  | 76,188,000 | 2,729,000 |  |
Equipment-Based Term Loan |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Borrowings on equipment based facility |  |  |  |  | 3,500,000 |  |
Debt extinguishment |  |  |  |  | 300,000 |  |
Line of credit, maximum borrowing capacity |  |  |  |  |  |  | 20,000,000
Repayments of long-term debt |  |  |  |  | $ 10,000,000 |  |
Equipment Based Revolving Line Of Credit |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Line of credit, maximum borrowing capacity |  |  |  |  |  |  | $ 20,000,000
Warrants to the Lenders Under the Loan Agreement |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Warrants value |  |  | $ 3,500,000 | 3,500,000 |  |  |
Tealstone |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Promissory notes issued to the sellers |  |  | 5,000,000 |  |  |  |
Cash, net of cash acquired |  |  | $ 54,861,000 |  |  |  |
Fair value inputs, discount rate |  |  | 12.00% |  |  |  |
Notes and deferred payments to sellers |  |  | $ 11,600,000 |  |  |  |
Accretion expense |  |  |  | $ 800,000 |  |  |
Scenario, Forecast | Tealstone |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Cash, net of cash acquired | $ 7,500,000 | $ 2,426,000 |  |  |  |  |
Minimum | Notes Payable for Transportation and Construction Equipment |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, term |  |  |  | 3 years |  |  |
Stated interest rate |  |  |  | 3.15% |  |  |
Maximum | Notes Payable for Transportation and Construction Equipment |  |  |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |  |  |
Debt instrument, term |  |  |  | 5 years |  |  |
Stated interest rate |  |  |  | 6.92% |  |  |

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- Definition Represents the maximum incurrence of net capital expenditures during each of four consecutive fiscal quarters under the financial covenants pursuant to a debt instrument. + References No definition available. + Details
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- Definition Represents the maximum ratio of secured indebtedness to EBITDA, for a certain specified first period of time following the current date, under the financial covenants pursuant to a debt instrument. + References No definition available. + Details
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- Definition Represents the minimum rolling four quarter gross margin in contract backlog, for a certain specified first period of time following the current date, under the financial covenants pursuant to a debt instrument. + References No definition available. + Details
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- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
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- Definition Amount, after accumulated amortization, of debt issuance costs. Includes, but is not limited to, legal, accounting, underwriting, printing, and registration costs. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28555-108399 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.17) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Interest rate used to find the present value of an amount to be paid or received in the future as an input to measure fair value. For example, but not limited to, weighted average cost of capital (WACC), cost of capital, cost of equity and cost of debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 820 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (bbb) -URI http://asc.fasb.org/extlink&oid=66048111&loc=d3e19207-110258 + Details
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- Definition The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 + Details
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- Definition Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(b),22(b)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
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- Definition Amount of cash outflow for cost from early extinguishment and prepayment of debt. Includes, but is not limited to, third-party cost, premium paid, and other fee paid to lender directly for debt extinguishment or debt prepayment. Excludes accrued interest. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 15 -Subparagraph (g) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3291-108585 + Details
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