Infrastructure and Energy Alternatives (IEA) 10-Q 10 May 21 2021 Q1 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2021	May 10, 2021
Entity Central Index Key	0001652362
Document Fiscal Year Focus	2021
Amendment Flag	false
Current Fiscal Year End Date	--12-31
Document Fiscal Period Focus	Q1
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Mar. 31, 2021
Document Transition Report	false
Entity File Number	001-37796
Entity Registrant Name	Infrastructure & Energy Alternatives, Inc.
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	47-4787177
Entity Address, Address Line One	6325 Digital Way
Entity Address, Address Line Two	Suite 460
Entity Address, City or Town	Indianapolis
Entity Address, State or Province	IN
Entity Address, Postal Zip Code	46278
City Area Code	765
Local Phone Number	828-2580
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		24,847,908
Common Stock, $0.0001 par value
Title of 12(b) Security	Common Stock, $0.0001 par value
Trading Symbol	IEA
Security Exchange Name	NASDAQ
Warrants for Common Stock
Title of 12(b) Security	Warrants for Common Stock
Trading Symbol	IEAWW
Security Exchange Name	NASDAQ

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash and cash equivalents	$ 95,173	$ 164,041
Accounts receivable, net	171,306	163,793
Contract Assets	146,696	145,183
Prepaid expenses and other current assets	46,656	19,352
Total current assets	459,831	492,369
Property, plant and equipment, net	127,264	130,746
Operating Lease, Right-of-Use Asset	34,994	36,461
Intangible Assets, Net (Excluding Goodwill)	23,818	25,434
Goodwill	37,373	37,373
Company-owned life insurance	4,519	4,250
Deferred Income Tax Assets, Net	4,461	2,069
Other Assets, Noncurrent	436	438
Total assets	692,696	729,140
Current liabilities:
Accounts Payable, Current	86,826	104,960
Accrued Liabilities, Current	116,793	129,594
Contract Liabilities	141,420	118,235
Current portion of finance lease obligations	24,728	25,423
Operating Lease, Liability, Current	8,779	8,835
Current portion of long-term debt	2,379	2,506
Total current liabilities	380,925	389,553
Finance lease obligations, less current portion	27,053	32,146
Operating Lease, Liability, Noncurrent	27,736	29,154
Long-term Debt	160,229	159,225
Debt - Series B Preferred Stock	175,164	173,868
Warrant Obligations	9,500	9,200
Deferred compensation	8,039	8,672
Total liabilities	788,646	801,818
Commitments and contingencies:
Series A Preferred Stock, par value, $0.0001 per share; 1,000,000 shares authorized; 17,483 shares and 17,483 shares issued and outstanding at March 31, 2021 and December 31, 2020, respectively	17,483	17,483
Stockholders' equity (deficit):
Common stock, par value, $0.0001 per share; 150,000,000 and 150,000,000 shares authorized; 23,348,353 and 21,008,745 shares issued and 23,348,353 and 21,008,745 outstanding at March 31, 2021 and December 31, 2020, respectively	2	2
Additional paid in capital	32,467	35,305
Accumulated deficit	(145,902)	(125,468)
Total stockholders' deficit	(113,433)	(90,161)
Total liabilities and stockholders' deficit	$ 692,696	$ 729,140
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	17,483	17,483
Preferred stock, shares outstanding	17,483	17,483
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares, issued	23,348,353	21,008,745
Common stock, shares, outstanding	23,348,353	21,008,745

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Mar. 31, 2021	Dec. 31, 2020
Statement of Financial Position [Abstract]
Preferred stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Preferred stock, shares authorized	1,000,000	1,000,000
Preferred stock, shares issued (in shares)	17,483	17,483
Preferred stock, shares outstanding	17,483	17,483
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	150,000,000	150,000,000
Common stock, shares, issued	23,348,353	21,008,745
Common stock, shares, outstanding	23,348,353	21,008,745

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Revenue	$ 276,412	$ 358,163
Cost of revenue	259,871	325,122
Gross profit	16,541	33,041
Selling, general and administrative expenses	24,846	29,484
Loss income from operations	(8,305)	3,557
Other income (expense), net:
Interest expense, net	(14,359)	(16,065)
Other expense	(162)	(1,102)
Loss before benefit for income taxes	(22,826)	(13,610)
Benefit for income taxes	2,392	867
Net loss	(20,434)	(12,743)
Less: Convertible Preferred Stock dividends	(656)	(766)
Net Income (Loss) Available to Common Stockholders, Basic	$ (21,090)	$ (13,509)
Earnings Per Share, Basic	$ (0.91)	$ (0.66)
Earnings Per Share, Diluted	$ (0.91)	$ (0.66)
Weighted Average Number of Shares Outstanding, Basic	23,057,731	20,522,216
Weighted Average Number of Shares Outstanding, Diluted	23,057,731	20,522,216

Condensed Statements of Stockho

Condensed Statements of Stockholders Equity (Deficit) Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock, $0.0001 par value	Common Stock, $0.0001 par valueCommon Stock, $0.0001 par value	Additional Paid-in Capital	Additional Paid-in CapitalCommon Stock, $0.0001 par value	Treasury Stock	Treasury StockTreasury Stock	Retained Earnings
Beginning Balance Shares, Issued at Dec. 31, 2019		20,461				(14)
Beginning Balance Stockholder's equity at Dec. 31, 2019	$ (109,103)	$ 2		$ 17,167		$ (76)		$ (126,196)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(12,743)							(12,743)
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	1,113			1,113
Stock Issued During Period, Shares, New Issues			240
Stock Issued During Period, Value, New Issues	196	$ 0			$ 280
Adjustments to Additional Paid in Capital, Warrant Issued	15,631			15,631
Treasury Stock, Shares							(38)
Dividends, Preferred Stock, Stock	(766)			(766)
Ending Balance Shares, Issued at Mar. 31, 2020		20,701				(52)
Ending Balance Stockholder's equity at Mar. 31, 2020	(105,672)	$ 2		33,425		$ (160)		(138,939)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Treasury Stock, Value							$ (84)
Beginning Balance Shares, Issued at Dec. 31, 2020		21,009				0
Beginning Balance Stockholder's equity at Dec. 31, 2020	(90,161)	$ 2		35,305		$ 0		(125,468)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net loss	(20,434)							(20,434)
Shares Issued, Earnout shares			1,803
APIC, Share-based Payment Arrangement, Increase for Cost Recognition	727			727
Stock Issued During Period, Shares, New Issues			521
Stock Issued During Period, Shares, Other			15
Adjustments to Additional Paid in Capital, Income Tax Deficiency from Share-based Compensation	(2,909)				$ (2,909)
Dividends, Preferred Stock, Stock	(656)			(656)
Ending Balance Shares, Issued at Mar. 31, 2021		23,348				0
Ending Balance Stockholder's equity at Mar. 31, 2021	$ (113,433)	$ 2		$ 32,467		$ 0		$ (145,902)

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Cash flows from operating activities:
Net loss	$ (20,434)	$ (12,743)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	10,799	11,888
Fair Value Adjustment of Warrants	300	1,057
Amortization of Other Deferred Charges	2,859	2,237
Share-based compensation expense	727	1,113
Deferred compensation	0	(1,371)
Accrued dividends on Series B Preferred Stock	0	7,959
Deferred income taxes	(2,392)	(1,080)
Other Operating Activities, Cash Flow Statement	(902)	733
Change in operating assets and liabilities:
Accounts receivable	(7,513)	48,931
Increase (Decrease) in Contract with Customer, Asset	1,513	14,548
Prepaid expenses and other assets	(27,304)	(5,212)
Accounts payable and accrued liabilities	(31,593)	(104,760)
Increase (Decrease) in Contract with Customer, Liability	23,186	(8,381)
Net cash used in operating activities	(53,780)	(74,177)
Cash flow from investing activities:
Company-owned life insurance	(269)	599
Purchases of property, plant and equipment	(3,920)	(2,231)
Proceeds from sale of property, plant and equipment	667	1,719
Net cash (used in) provided by investing activities	(3,522)	87
Cash flows from financing activities:
Proceeds from Long-term Lines of Credit	0	46,000
Repayments of Long-term Lines of Credit	(686)	(55,853)
Payments on finance lease obligations	(7,971)	(5,781)
Proceeds from Convertible Debt	0	350
Proceeds, Issuance of Shares, Share-based Payment Arrangement, Including Option Exercised	0	196
Payment, Tax Withholding, Share-based Payment Arrangement	(2,909)	0
Net cash used in financing activities	(11,566)	(15,088)
Net change in cash and cash equivalents	(68,868)	(89,178)
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Period Start	164,041	147,259
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents Period End	95,173	58,081
Supplemental disclosure of cash and non-cash transactions:
Interest Paid, Excluding Capitalized Interest, Operating Activities	10,691	6,053
Income Taxes Paid, Net	(290)	(229)
Right-of-Use Asset Obtained in Exchange for Finance Lease Liability	2,183	2,806
Right-of-Use Asset Obtained in Exchange for Operating Lease Liability	1,101	2,732
Dividends, Preferred Stock	$ 656	$ 766

Business, Basis of Presentation

Business, Basis of Presentation and Significant Accounting Policies	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies	Business, Basis of Presentation and Significant Accounting Policies Organization and Reportable Segments Infrastructure and Energy Alternatives, Inc., a Delaware corporation, is a holding company organized on August 4, 2015 (together with its wholly-owned subsidiaries, “IEA” or the “Company”). On March 26, 2018, we became a public company by consummating a merger (the “Merger”) pursuant to an Agreement and Plan of Merger, dated November 3, 2017, with M III Acquisition Corporation (“M III”). We segregate our business into two reportable segments: the Renewables segment and the Specialty Civil segment. See Note 10. Segments for a description of the reportable segments and their operations. Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with the instructions for Quarterly Reports on Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual audited consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. Adjustments necessary to arrive at net income (loss) available for common stockholders, previously disclosed in Note 8. Earnings Per Share , have been added to the prior period presentation of the consolidated statements of operations to be comparable with the current period presentation. The unaudited condensed consolidated financial statements include the accounts of IEA and its wholly-owned domestic and foreign subsidiaries. The Company occasionally forms joint ventures with unrelated third parties for the execution of single contracts or projects. The Company assesses its joint ventures to determine if they meet the qualifications of a variable interest entity (“VIE”) in accordance with Accounting Standard Codification (“ASC”) Topic 810, Consolidation. For construction joint ventures that are not VIEs or fully consolidated but for which the Company has significant influence, the Company accounts for its interest in the joint ventures using the proportionate consolidation method, see Note 11. Joint Ventures. In the opinion of management, these financial statements reflect all adjustments (consisting of normal recurring adjustments) that are necessary to present fairly the results of operations for the interim periods presented. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. These financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2020 and notes thereto included in the Company’s 2020 Annual Report on Form 10-K. Basis of Accounting and Use of Estimates The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP. The preparation of the condensed consolidated financial statements in conformity with GAAP requires the use of estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and the accompanying notes. Key estimates include: the recognition of revenue and project profit or loss; fair value estimates; valuations of goodwill and intangible assets; asset lives used in computing depreciation and amortization; accrued self-insured claims; other reserves and accruals; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that its estimates are reasonable when considered in conjunction with the Company’s consolidated financial position and results of operations, actual results could differ materially from those estimates. Revenue Recognition The Company derives revenue primarily from construction projects performed under contracts for specific projects requiring the construction and installation of an entire infrastructure system or specified units within an infrastructure system. Contracts contain multiple pricing options, such as fixed price, time and materials, or unit price. Generally, renewable energy projects are performed for private customers while Specialty Civil projects are performed for various governmental entities. Revenue derived from projects billed on a fixed-price basis totaled 96.2% and 96.0% of consolidated revenue from operations for the three months ended March 31, 2021 and 2020, respectively. Revenue and related costs for contracts billed on a time and materials basis are recognized as the services are rendered. Revenue derived from projects billed on a time and materials basis totaled 3.8% and 4.0% of consolidated revenue from operations for the three months ended March 31, 2021 and 2020, respectively. Construction contract r evenue is recognized over time using the cost-to-cost measure of progress for fixed price contracts. The cost-to-cost measure of progress best depicts the continuous transfer of control of goods or services to the customer. The contractual terms provide that the customer compensates the Company for services rendered. Contract costs include all direct materials, labor and subcontracted costs, as well as indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and the costs of capital equipment. The cost estimation and review process for recognizing revenue over time under the cost-to-cost method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of total contract transaction price and total project costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected variable consideration are factors that influence estimates of the total contract transaction price, total costs to complete those contracts and profit recognition. Changes in these factors could result in revisions to revenue and costs of revenue in the period in which the revisions are determined on a prospective basis, which could materially affect the Company’s results of operations for that period. Provisions for losses on uncompleted contracts are recorded in the period in which such losses are determined. Performance Obligations A performance obligation is a contractual promise to transfer a distinct good or service to the customer and is the unit of account under ASC Topic 606. The transaction price of a contract is allocated to distinct performance obligations and recognized as revenue when or as the performance obligations are satisfied. The Company’s contracts often require significant integrated services and, even when delivering multiple distinct services, are generally accounted for as a single performance obligation. Contract amendments and change orders are generally not distinct from the existing contract due to the significant integrated service provided in the context of the contract and are accounted for as a modification of the existing contract and performance obligation. With the exception of certain Specialty Civil service contracts, the majority of the Company’s performance obligations are generally completed within one year. When more than one contract is entered into with a customer on or close to the same date, the Company evaluates whether those contracts should be combined and accounted for as a single contract as well as whether those contracts should be accounted for as more than one performance obligation. This evaluation requires significant judgment and is based on the facts and circumstances of the various contracts, which could change the amount of revenue and profit recognition in a given period depending upon the outcome of the evaluation. Remaining performance obligations represent the amount of unearned transaction prices for contracts, including approved and unapproved change orders. As of March 31, 2021, the amount of the Company’s remaining performance obligations was $1,627.5 million. The Company expects to recognize approximately 67.7% of its remaining performance obligations as revenue during the next twelve months. Revenue recognized from performance obligations satisfied in previous periods was $0.4 million and $(2.0) million for the three months ended March 31, 2021 and 2020, respectively. Variable Consideration Transaction pricing for the Company’s contracts may include variable consideration, such as unapproved change orders, claims, incentives and liquidated damages. Management estimates variable consideration for a performance obligation utilizing estimation methods that best predict the amount of consideration to which the Company will be entitled. Variable consideration is included in the estimated transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Management’s estimates of variable consideration and determination of whether to include estimated amounts in transaction price are based on legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer and all other relevant information that is reasonably available. The effect of a change in variable consideration on the transaction price of a performance obligation is typically recognized as an adjustment to revenue on a cumulative catch-up basis. To the extent unapproved change orders, claims and liquidated damages reflected in transaction price are not resolved in the Company’s favor, or to the extent incentives reflected in transaction price are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of March 31, 2021 and December 31, 2020, the Company included approximately $42.8 million and $52.6 million, respectively, of unapproved change orders and/or claims in the transaction price for certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments are included within Contract Assets or Contract Liabilities as appropriate. The Company actively engages with its customers to complete the final change order approval process, and generally expects these processes to be completed within one year. Amounts ultimately realized upon final acceptance by customers could be higher or lower than such estimated amounts. Disaggregation of Revenue The following tables disaggregate revenue by customers and services performed, which the Company believes best depicts the nature, amount, timing and uncertainty of its revenue: (in thousands) Three Months Ended March 31, 2021 March 31, 2020 Renewables Segment Wind $ 146,858 $ 248,537 Solar 33,516 209 $ 180,374 $ 248,746 Specialty Civil Segment Heavy civil $ 48,871 $ 41,222 Rail 26,868 47,057 Environmental 20,299 21,138 $ 96,038 $ 109,417 Concentrations The Company had the following approximate revenue and accounts receivable concentrations, net of allowances, for the periods ended: Revenue % Three Months Ended Accounts Receivable % March 31, 2021 March 31, 2020 March 31, 2021 December 31, 2020 Company A (Renewables Segment) * 11.5 % * * Company B (Renewables Segment) * 11.1 % * * * Amount was not above 10% threshold Construction Joint Ventures Certain contracts are executed through joint ventures. The arrangements are often formed for the execution of single contracts or projects and allow the Company to share risks and secure specialty skills required for project execution. In accordance with ASC Topic 810, Consolidation the Company assesses its joint ventures at inception to determine if any meet the qualifications of a VIE. The Company considers a joint venture a VIE if either (a) the total equity investment is not sufficient to permit the entity to finance its activities without additional subordinated financial support, (b) characteristics of a controlling financial interest are missing (either the ability to make decisions through voting or other rights, the obligation to absorb the expected losses of the entity or the right to receive the expected residual returns of the entity), or (c) the voting rights of the equity holders are not proportional to their obligations to absorb the expected losses of the entity and/or their rights to receive the expected residual returns of the entity and substantially all of the entity’s activities either involve or are conducted on behalf of an investor that has disproportionately few voting rights. Upon the occurrence of certain events outlined in ASC 810, the Company reassesses its initial determination of whether the joint venture is a VIE. The Company also evaluates whether it is the primary beneficiary of each VIE and consolidates the VIE if the Company has both (a) the power to direct the economically significant activities of the entity and (b) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to the VIE. The Company considers the contractual agreements that define the ownership structure, distribution of profits and losses, risks, responsibilities, indebtedness, voting rights and board representation of the respective parties in determining whether it qualifies as the primary beneficiary. The Company also considers all parties that have direct or implicit variable interests when determining whether it is the primary beneficiary. When the Company is determined to be the primary beneficiary, the VIE is consolidated. In accordance with ASC 810, management’s assessment of whether the Company is the primary beneficiary of a VIE is performed continuously. Construction joint ventures that do not involve a VIE, or for which the Company is not the primary beneficiary, are evaluated for consolidation under the voting interest model that considers whether the Company owns or controls more than 50% of the voting interest in the joint venture. For construction joint ventures that are not consolidated but for which the Company has significant influence, the Company accounts for its interest in the joint ventures using the proportionate consolidation method, whereby the Company’s proportionate share of the joint ventures’ assets, liabilities, revenue and cost of operations are included in the appropriate classifications in the Company’s consolidated financial statements. See Note 11. Joint Ventures for additional discussion regarding joint ventures. Recently Adopted Accounting Standards - Guidance Adopted in 2020 In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes,” which removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. Depending on the amendment, adoption may be applied on the retrospective, modified retrospective, or prospective basis. The Company adopted the standard on January 1, 2021 on a prospective basis, which did not have an impact on our disclosures for income taxes. Recently Issued Accounting Standards Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including trade accounts receivables. The expected credit loss methodology under ASU 2016-13 is based on historical experience, current conditions and reasonable and supportable forecasts, and replaces the probable/incurred loss model for measuring and recognizing expected losses under current GAAP. The ASU also requires disclosure of information regarding how a company developed its allowance, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. The ASU and its related clarifying updates are effective for smaller reporting companies for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years, with early adoption permitted. The Company is still evaluating the new standard but do not expect it to have a material impact on our estimate of the allowance for uncollectable accounts. Management has evaluated other recently issued accounting pronouncements and does not believe that they will have a significant impact on the financial statements and related disclosures. COVID-19 Pandemic During March 2020, the World Health Organization declared a global pandemic related to the rapidly growing outbreak of a novel strain of c oronavirus ( “ COVID-19 ” ). The COVID-19 pandemic has significantly affected economic conditions in the United States and internationally as national, state and local governments reacted to the public health crisis by requiring mitigation measures that have disrupted business activities for an uncertain period of time. The Company believes that the COVID-19 pandemic has not had a material adverse impact on the Company’s financial results for the period ended March 31, 2021. Currently, most of the Company’s construction services are deemed essential under governmental mitigation orders and all of our business segments continue to operate. The Company has issued several notices of force majeure for the purpose of recognizing delays in construction schedules due to COVID-19 outbreaks on certain of its work sites and has also received notices of force majeure from the owners of certain projects and certain subcontractors. Management does not believe that any delays on projects related to these events of force majeure will have a material impact on its results of operations. Management’s top priority has been to take appropriate actions to protect the health and safety of the Company's employees, customers and business partners, including adjusting the Company's standard operating procedures to respond to

Contract Assets and Liabilities

Contract Assets and Liabilities	3 Months Ended
	Mar. 31, 2021
Contractors [Abstract]
Contract Assets and Liabilities	Contract Assets and Liabilities The timing of when we bill our customers is generally dependent upon agreed-upon contractual terms, milestone billings based on the completion of certain phases of the work, or when services are provided. Sometimes, billing occurs subsequent to revenue recognition, resulting in unbilled revenue, which is accounted for as a contract asset. Sometimes we receive advance payments or deposits from our customers before revenue is recognized, resulting in deferred revenue, which is accounted for as a contract liability. Contract assets in the Condensed Consolidated Balance Sheets represent the following: • costs and estimated earnings in excess of billings, which arise when revenue has been recorded but the amount has not been billed; and • retainage amounts for the portion of the contract price billed by us for work performed but held for payment by the customer as a form of security until we reach certain construction milestones or complete the project. Contract assets consisted of the following: (in thousands) March 31, 2021 December 31, 2020 Costs and estimated earnings in excess of billings on uncompleted contracts $ 60,132 $ 51,367 Retainage receivable 86,564 93,816 $ 146,696 $ 145,183 Contract liabilities consist of the following: (in thousands) March 31, 2021 December 31, 2020 Billings in excess of costs and estimated earnings on uncompleted contracts $ 141,231 $ 117,641 Loss on contracts in progress 189 594 $ 141,420 $ 118,235 Revenue recognized for the three months ended March 31, 2021 that was included in the contract liability balance at December 31, 2020 was approximately $87.8 million. Activity in the allowance for doubtful accounts for the periods indicated was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Allowance for doubtful accounts at beginning of period $ — $ 75 Plus: provision for (reduction in) allowance — 14 Less: write-offs, net of recoveries — — Allowance for doubtful accounts at period end $ — $ 89

Property, plant and equipment,

Property, plant and equipment, net	3 Months Ended
	Mar. 31, 2020
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	Property, Plant and Equipment, Net Property, plant and equipment consisted of the following: (in thousands) March 31, 2021 December 31, 2020 Buildings and leasehold improvements $ 4,890 $ 4,402 Land 17,600 17,600 Construction equipment 197,057 192,402 Office equipment, furniture and fixtures 3,637 3,620 Vehicles 7,426 7,326 230,610 225,350 Accumulated depreciation (103,346) (94,604) Property, plant and equipment, net $ 127,264 $ 130,746

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net (Notes)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets Disclosure	Goodwill and Intangible Assets, Net The following table provides the changes in the carrying amount of goodwill, by segment: (in thousands) Renewables Specialty Civil Total January 1, 2020 $ 3,020 $ 34,353 $ 37,373 Adjustments — — — December 31, 2020 $ 3,020 $ 34,353 $ 37,373 Adjustments — — — March 31, 2021 $ 3,020 $ 34,353 $ 37,373 Intangible assets consisted of the following as of the dates indicated: March 31, 2021 December 31, 2020 ($ in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Life Customer relationships $ 26,500 $ (9,427) $ 17,073 4.75 years $ 26,500 $ (8,481) $ 18,019 5 years Trade name 13,400 (6,655) 6,745 2.75 years 13,400 (5,985) 7,415 3 years $ 53,800 $ (29,982) $ 23,818 $ 53,800 $ (28,366) $ 25,434 Amortization expense associated with intangible assets for the three months ended March 31, 2021 and 2020, totaled $1.6 million and $3.4 million, respectively. The following table provides the annual intangible amortization expense currently expected to be recognized for the years 2021 through 2025: (in thousands) Remainder of 2021 2022 2023 2024 2025 Amortization expense $ 4,849 $ 6,466 $ 5,841 $ 3,785 $ 2,876

Fair value of financial instrum

Fair value of financial instruments	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Fair value of financial instruments	Fair Value of Financial Instruments The Company applies ASC Topic 820, Fair Value Measurement, which establishes a framework for measuring fair value. ASC 820 defines fair value as an exit price, which is the price that would be received for an asset or paid to transfer a liability in the Company’s principal or most advantageous market in an orderly transaction between market participants on the measurement date. The fair value hierarchy established in ASC 820 generally requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. Observable inputs reflect the assumptions that market participants would use in pricing the asset or liability and are developed based on market data obtained from sources independent of the reporting entity. Unobservable inputs reflect the entity’s own assumptions based on market data and the entity’s judgments about the assumptions that market participants would use in pricing the asset or liability and are developed based on the best information available in the circumstances. The valuation hierarchy is composed of three levels. The classification within the valuation hierarchy is based on the lowest level of input that is significant to the fair value measurement. The levels within the valuation hierarchy are described below: Level 1 — Inputs to the fair value measurement are observable inputs, such as quoted prices in active markets for identical assets or liabilities listed on active market exchanges. Level 2 — Inputs to the fair value measurement are determined using prices for recently traded assets and liabilities with similar underlying terms, as well as direct or indirect observable inputs, such as interest rates and yield curves that are observable at commonly quoted intervals. Level 3 — Inputs to the fair value measurement are unobservable inputs, such as estimates, assumptions, and valuation techniques when little or no market data exists for the assets or liabilities. The following table sets forth information regarding the Company's liabilities measured at fair value on a recurring basis: March 31, 2021 December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Liabilities Private warrants $ — $ 1,000 $ — $ 1,000 $ — $ — $ — $ — Series B Preferred Stock - Anti-dilution warrants — — 8,100 8,100 — — 8,800 8,800 Series B-1 Preferred Stock - Performance warrants — — 400 400 — — 400 400 Total liabilities $ — $ 1,000 $ 8,500 $ 9,500 $ — $ — $ 9,200 $ 9,200 The following is a reconciliation of the beginning and ending balances of recurring fair value measurements using Level 3 inputs: (in thousands) Series B Preferred Stock - Anti-dilution warrants Series B-1 Preferred Stock - Performance warrants Beginning Balance, December 31, 2020 $ 8,800 $ 400 Fair value adjustment - loss (gain) recognized in other income (700) — Ending Balance, March 31, 2021 $ 8,100 $ 400 In 2019, the Company entered into three equity purchase agreements and issued Series B Preferred Stock as discussed in Note 6. Debt and Series B Preferred Stock . The agreements require that on the conversion of any of the Convertible Series A Preferred Stock to common shares, the Series B Preferred Stock will receive additional warrants (Anti-dilution Warrants) to purchase common shares at a price of $0.0001 per share. The agreements also require that if the Company fails to meet a certain Adjusted EBITDA (as that term is defined in the agreements) threshold on a trailing twelve-month basis from May 31, 2020 through April 30, 2021, the Series B Preferred Stock will receive additional warrants (Performance Warrants) to purchase common shares at $0.0001 per share. On May 20, 2019, the conversion rights for the Series A Preferred Stock were amended to allow the holders of Series A Preferred Stock to convert all or any portion of Series A Preferred Stock outstanding into common stock at any point in time. The information below describes the balance sheet classification and the recurring fair value measurement for these requirements: Private Warrants (recurring) - The Company has 295,000 private warrants that are not actively traded on the public markets and the Company adjusts the fair value at the end of each fiscal period using the price on that date multiplied by the remaining private warrants. The Private warrants were recorded as Warrant obligations at the end of the quarter and the fair value adjustment was recorded as other expense for the three months ended March 31, 2021. For further discussion see Note 8. Earnings Per Share . Series B Preferred Stock - Anti-dilution Warrants (recurring) - The number of common shares attributable to the warrants issued to Series B Preferred Stockholders upon conversion by Series A Preferred Stockholders is determined on a 30-day volume weighted average. The Anti-dilution warrant liability was valued using the stock price at the end of the quarter and were recorded as a liability. Series B-1 Preferred Stock - Performance Warrants (recurring) - The warrant liability was recorded at fair value as a liability, using a Monte Carlo Simulation based on certain significant unobservable inputs, such as a risk rate premium, Adjusted EBITDA volatility, stock price volatility and projected Adjusted EBITDA for the Company. Other financial instruments of the Company not listed in the table consist of cash and cash equivalents, accounts receivable, accounts payable and other current liabilities that approximate their fair values. Additionally, management believes that the outstanding recorded balance on the line of credit and long-term debt, approximates fair value due to their floating interest rates.

Debt and Series B Preferred Sto

Debt and Series B Preferred Stock	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Debt and Series B Preferred Stock	Debt and Series B Preferred Stock Debt consisted of the following obligations as of: (in thousands) March 31, 2021 December 31, 2020 Term loan $ 173,345 $ 173,345 Commercial equipment notes 4,897 5,582 Total principal due for long-term debt 178,242 178,927 Unamortized debt discount and issuance costs (15,634) (17,196) Less: Current portion of long-term debt (2,379) (2,506) Long-term debt, less current portion $ 160,229 $ 159,225 Debt - Series B Preferred Stock $ 185,998 $ 185,396 Unamortized debt discount and issuance costs (10,834) (11,528) Long-term Series B Preferred Stock $ 175,164 $ 173,868 The weighted average interest rate for the term loan as of March 31, 2021 and December 31, 2020, was 6.95% and 7.00%, respectively. Debt Covenants The term loan is governed by the terms of the Third A&R Credit Agreement, dated May 2019, which include customary affirmative and negative covenants and provide for customary events of default, including, nonpayment of principal or interest and failure to timely deliver financial statements. Under the Third A&R Credit Agreement, the financial covenant provides that the First Lien Net Leverage Ratio (as defined therein) may not exceed 2.75:1.0, for the four fiscal quarters ending December 31, 2021, and for all subsequent quarters, 2.25:1.0. The Third A&R Credit Agreement also includes certain limitations on the payment of cash dividends on the Company's common shares and provides for other restrictions on (subject to certain exceptions) liens, indebtedness (including guarantees and other contingent obligations), investments (including loans, advances and acquisitions), mergers and other fundamental changes and sales and other dispositions of property or assets, among others. Debt - Series B Preferred Stock The Series B Preferred Stock is a mandatorily redeemable financial instrument under ASC Topic 480 and has been recorded as a liability using the effective interest rate method for each tranche. The mandatory redemption date for all tranches of the Series B Preferred Stock is February 15, 2025. The Series B Preferred Stock requires quarterly dividend payments calculated at a 12% annual rate on all outstanding Series B Preferred Stock when the Company’s First Lien Net Leverage Ratio (as defined in the Third A&R Credit Agreement) is less than or equal to 1.50:1.0 and a 13.5% rate if the ratio if greater. The Series B Preferred Stock agreements allow the Company to accrue, but not pay, the dividends at a 15.0% annual rate. Accrued dividends increase the amount of Series B Preferred Stock. Accrued dividends were $18.3 million at March 31, 2021 and December 31, 2020, respectively. Dividend payments are not deductible in calculating the Company’s federal and state income taxes. Contractual Maturities Contractual maturities of the Company's outstanding principal on debt obligations as of March 31, 2021: (in thousands) Maturities Remainder of 2021 $ 1,821 2022 16,938 2023 29,986 2024 129,368 2025 129 Thereafter — Total contractual maturities $ 178,242

Commitments and contingencies

Commitments and contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and Contingencies In the ordinary course of business, the Company enters into agreements that provide financing for its machinery and equipment, facility and vehicle needs. The Company reviews these agreements for potential lease classification, and at inception, determines whether a lease is an operating or finance lease. Lease assets and liabilities, which generally represent the present value of future minimum lease payments over the term of the lease, are recognized as of the commencement date. Under Topic 842, leases with an initial lease term of twelve months or less are classified as short-term leases and are not recognized in the condensed consolidated balance sheets unless the lease contains a purchase option that is reasonably certain to be exercised. Lease term, discount rate, variable lease costs and future minimum lease payment determinations require the use of judgment as these are based on the facts and circumstances related to each specific lease. Lease terms are generally based on their initial non-cancelable terms, unless there is a renewal option that is reasonably certain to be exercised. Various factors, including economic incentives, intent, past history and business need are considered to determine if a renewal option is reasonably certain to be exercised. The implicit rate in a lease agreement is used when it can be determined. Otherwise, the Company's incremental borrowing rate, which is based on information available as of the lease commencement date, including applicable lease terms and the current economic environment, is used to determine the value of the lease obligation. Finance Leases The Company has obligations, exclusive of associated interest, under various finance leases for equipment totaling $51.8 million and $57.6 million at March 31, 2021 and December 31, 2020, respectively. Gross property under this capitalized lease agreement at March 31, 2021 and December 31, 2020, totaled $129.7 million and $128.0 million, less accumulated depreciation of $60.7 million and $55.1 million, respectively, for net balances of $69.0 million and $72.9 million, respectively. Depreciation expense for assets held under the finance leases is included in cost of revenue in the condensed consolidated statements of operations. The future minimum payments of finance lease obligations are as follows: (in thousands) Remainder of 2021 $ 19,994 2022 21,996 2023 7,267 2024 3,264 2025 1,799 Thereafter 78 Future minimum lease payments 54,398 Less: Amount representing interest (2,617) Present value of minimum lease payments 51,781 Less: Current portion of finance lease obligations 24,728 Finance lease obligations, less current portion $ 27,053 Operating Leases In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facilities, vehicles and equipment. The Company has obligations, exclusive of associated interest, totaling $36.5 million and $38.0 million at March 31, 2021 and December 31, 2020, respectively. Property under these operating lease agreements at March 31, 2021 and December 31, 2020, totaled $35.0 million and $36.5 million, respectively. The Company has long-term power-by-the-hour equipment rental agreements with a construction equipment manufacturer that have a guaranteed minimum monthly hour requirement. The minimum guaranteed amount based on the Company's current operations is $3.2 million per year. Total expense under these agreements are listed in the following table as variable lease costs. The future minimum payments under non-cancelable operating leases are as follows: (in thousands) Remainder of 2021 $ 8,435 2022 9,753 2023 7,347 2024 3,532 2025 1,751 Thereafter 18,899 Future minimum lease payments 49,717 Less: Amount representing interest (13,202) Present value of minimum lease payments 36,515 Less: Current portion of operating lease obligations 8,779 Operating lease obligations, less current portion $ 27,736 Lease Information Three Months Ended March 31, 2021 March 31, 2020 Finance Lease cost: Amortization of right-of-use assets $ 5,835 $ 5,697 Interest on lease liabilities 817 1,186 Operating lease cost 3,394 3,478 Short-term lease cost 23,604 21,635 Variable lease cost 1,247 960 Sublease Income (33) (33) Total lease cost $ 34,864 $ 32,923 Other information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 817 $ 1,186 Operating cash flows from operating leases $ 3,245 $ 3,342 Weighted-average remaining lease term - finance leases 2.41 years 2.73 years Weighted-average remaining lease term - operating leases 8.17 years 8.02 years Weighted-average discount rate - finance leases 6.18 % 6.49 % Weighted-average discount rate - operating leases 7.00 % 7.14 % Letters of Credit and Surety Bonds

Earnings per share

Earnings per share	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Earnings per share	Earnings Per Share The Company calculates earnings (loss) per share (“EPS”) in accordance with ASC Topic 260, Earnings per Share . Basic EPS is computed by dividing income (loss) available to common stockholders by the weighted average number of common shares of common stock outstanding during the period. Income (loss) available to common stockholders is computed by deducting the dividends accrued for the period on cumulative preferred stock from net income and net income allocated to participating securities. If there is a net loss, the amount of the loss is increased by those preferred dividends. Diluted EPS assumes the dilutive effect of (i) Series A cumulative convertible preferred stock, using the if-converted method, (ii) publicly traded warrants, (iii) Series B Preferred Stock - Warrants and (iv) the assumed exercise of in-the-money stock options and the assumed vesting of outstanding restricted stock units (“RSUs”), using the treasury stock method. Whether the Company has net income, or a net loss determines whether potential issuances of common stock are included in the diluted EPS computation or whether they would be anti-dilutive. As a result, if there is a net loss, diluted EPS is computed in the same manner as basic EPS is computed. Similarly, if the Company has net income but its preferred dividend adjustment made in computing income available to common stockholders results in a net loss available to common stockholders, diluted EPS would be computed the same as basic EPS. The calculations of basic and diluted EPS, are as follows: Three Months Ended March 31, ($ in thousands, except per share data) 2021 2020 Numerator: Net loss $ (20,434) $ (12,743) Less: Convertible Preferred Stock dividends (656) (766) Net loss available to common stockholders (21,090) (13,509) Denominator: Weighted average common shares outstanding - basic and diluted 23,057,731 20,522,216 Anti-dilutive: Convertible Series A Preferred 1,628,269 6,553,041 Merger Warrants (1) 3,074,481 — Series B Preferred - Warrants (2) 7,684,057 7,675,325 Options (3) 426,824 — RSUs (3) 1,958,045 1,456,359 Basic EPS (0.91) (0.66) Diluted EPS (0.91) (0.66) (1) As of March 31, 2020, Merger Warrants to purchase 8,480,000 shares of common stock at $11.50 per share were not considered as dilutive as the warrants’ exercise price was not greater than the average market price of the common stock during the period. As of March 31, 2021, these warrants were calculated using the treasury stock method and were anti-dilutive. (2) Series B Preferred - Warrants are considered as participating securities because the holders are entitled to participate in any distributions similar to that of common shareholders. (3) As of March 31, 2020, there were 591,860 of vested and unvested options and 141,248 unvested RSUs, respectively. These were also not considered as dilutive as the respective exercise price or average stock price required for vesting of such awards was greater than the average market price of the common stock during the period. Merger Warrants On August 4, 2015, M III formed a Special Purpose Acquisition Corporation and issued public and private warrants before the Merger with the Company. As of March 31, 2021, the Company had 16,925,160 Merger Warrants outstanding, of which 295,000 are considered private warrants. Two Merger Warrants, such warrants will be exercisable for one share of our Common Stock at $11.50 per share until the expiration on March 26, 2023. For further discussion about the valuation of the private warrants see Note 5. Fair Value of Financial Instruments. Series B Preferred Stock Anti-dilution Warrants The Company also had the following potential outstanding warrants related to the Series B Preferred Stock issuance. • At March 31, 2021, a total of 495,762 warrants calculated on an if-converted method for the conversion of shares related to the outstanding Series A Preferred Stock. As discussed in Note 5. Fair Value of Financial Instruments , these warrants are recorded as a liability. These warrants are not included in the weighted average share calculation as the contingent event (conversion of Series A Preferred Stock) had not occurred at the end of the quarter. • The second set of additional warrants would be issued if the exercise of any warrant with an exercise price of $11.50 or higher. • The final set of additional warrants would be issued if the exercise of any equity issued pursuant to the Company’s long term incentive plan or other equity plan with a strike price of $11.50 or higher. Series A Preferred Stock As of March 31, 2021, we had 17,483 shares of Series A Preferred Stock with a stated value of $1,000 per share plus accumulated dividends. Dividends are paid on the Series A Preferred Stock as, if and when declared by our Board. To extent permitted, dividends are required to be paid in cash quarterly in arrears on each March 31, June 30, September 30 and December 31 on the stated value at a rate of 10% per annum. If not paid in cash, dividends will accrue on the stated value and will increase the stated value on and effective as of the applicable dividend date without any further action by the Board at 12% per annum. So long as any shares of Series B Preferred Stock of the Company are currently outstanding or from and after the occurrence of any non-payment event or default event and until cured or waived, the foregoing rates will increase by 2% per annum. As of March 31, 2021, the Company has accrued a cumulative of $5.0 million in dividends to the holder of Series A Preferred Stock as a reduction to additional paid-in capital. Stock Compensation Under guidance of ASC Topic 718 “Compensation — Stock Compensation,” stock-based compensation expense is measured at the date of grant, based on the calculated fair value of the stock-based award, and is recognized as an expense over the employee’s requisite service period (generally the vesting period of the award). The fair value of the RSUs was based on the closing market price of our common stock on the date of the grant. Stock compensation expense for the RSUs is being amortized using the straight-line method over the service period. For the three months ended March 31, 2021 and 2020, we recognized $0.7 million and $1.1 million in compensation expense, respectively.

Income taxes

Income taxes	3 Months Ended
	Mar. 31, 2021
Income Tax Disclosure [Abstract]
Income taxes	Income Taxes The Company’s statutory federal tax rate was 21.00% for the periods ended March 31, 2021 and 2020, respectively. State tax rates for the same period vary among states and range from approximately 0.8% to 12.0%. A small number of states do not impose an income tax. The effective tax rates for the three months ended March 31, 2021 and 2020 were 10.5% and 6.4%, respectively. The difference between the Company’s effective tax rate and the federal statutory rate primarily results from permanent differences related to the interest accrued for the Series B Preferred Stock and executive compensation, which are not deductible for federal and state income taxes. There were no changes in uncertain tax positions during the periods ended March 31, 2021 and 2020. On March 27, 2020, the Coronavirus Aid, Relief, and Economic Security Act (the “CARES Act”) was enacted by the US Government in response to the COVID-19 pandemic to provide employment retention incentives. We do not believe that these relief measures materially affect the condensed consolidated financial statements for the last three quarters of 2020. The Company has also made use of the payroll deferral provision to defer social security tax of approximately $13.6 million through December 31, 2020. Half of this amount is required to be paid on December 31, 2021 and the other half by December 31, 2022.

Segments (Notes)

Segments (Notes)	3 Months Ended
	Mar. 31, 2021
Segments [Abstract]
Segment Reporting Disclosure	Segments We operate our business as two reportable segments: the Renewables segment and the Specialty Civil segment. Each of our reportable segments is comprised of similar business units that specialize in services unique to their respective markets. The classification of revenue and gross profit for segment reporting purposes can at times require judgment on the part of management. Our segments may perform services across industries or perform joint services for customers in multiple industries. To determine reportable segment gross profit, certain allocations, including allocations of shared and indirect costs, such as facility costs, equipment costs and indirect operating expenses, were made based on segment revenue. Separate measures of the Company’s assets, including capital expenditures and cash flows by reportable segment are not produced or utilized by management to evaluate segment performance. A substantial portion of the Company’s fixed assets are owned by and accounted for in our equipment department, including operating machinery, equipment and vehicles, as well as office equipment, buildings and leasehold improvements, and are used on an interchangeable basis across our reportable segments. As such, for reporting purposes, total under/over absorption of equipment expenses consisting primarily of depreciation is allocated to the Company's two reportable segments based on segment revenue. The following is a brief description of the Company's reportable segments: Renewables Segment The Renewables segment operates throughout the United States and specializes in a range of services for the power delivery, solar, wind and battery storage markets that includes design, procurement, construction, restoration, and maintenance. Specialty Civil Segment The Specialty Civil segment operates throughout the United States and specializes in a range of services that include: • Heavy civil construction services such as road and bridge construction, specialty paving, sports field development, industrial maintenance, outsourced contract mining and heavy hauling. • Environmental remediation services such as site development, environmental site closure, and coal ash management. • Rail infrastructure services such as planning, design, procurement, construction and maintenance of major railway and intermodal facilities. Segment Revenue Revenue by segment was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Segment Revenue % of Total Revenue Revenue % of Total Revenue Renewables $ 180,374 65.3 % $ 248,746 69.5 % Specialty Civil 96,038 34.7 % 109,417 30.5 % Total revenue $ 276,412 100.0 % $ 358,163 100.0 % Segment Gross Profit Gross profit by segment was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Segment Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Renewables $ 12,180 6.8 % $ 25,829 10.4 % Specialty Civil 4,361 4.5 % 7,212 6.6 % Total gross profit $ 16,541 6.0 % $ 33,041 9.2 %

Investments, Equity Method and

Investments, Equity Method and Joint Ventures	3 Months Ended
	Mar. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Equity Method Investments and Joint Ventures Disclosure	Joint Ventures As of March 31, 2021, the Company did not have any VIEs but did have one joint venture that used the proportionate consolidation method at 25% ownership. The following balances were included in the condensed consolidated financial statements: (in thousands) March 31, 2021 Assets Cash $ 5,455 Accounts receivable 3,963 Contract assets 1,446 Liabilities Accounts payable $ 3,461 Contract liabilities 7,403 Three Months Ended March 31, 2021 Revenue $ 4,501 Cost of revenue 4,501

Related party transactions

Related party transactions	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Related party transactions	Related Party TransactionsOn February 9, 2021, Ares Management, LLC, on behalf of its affiliated funds, investment vehicles and/or managed accounts (“Ares”) purchased the outstanding Series B Preferred Stock and Series A Preferred Stock from funds managed by Oaktree Capital Management (“Oaktree”). As of March 31, 2021, Ares currently holds all of the outstanding Series B Preferred Stock, except for 350 shares, and all of the outstanding Series A Preferred Stock. Related Party Shareholders Type of Equity Holder Ownership Percentage Series A Preferred Stock and Series A Conversion Warrants Ares 100 % Series B-1 Preferred Stock, Performance Warrants, Warrants at Closing (initial amount issued) Ares 100 % Series B-1 Warrants at Closing (initial amount issued), Exchange Warrants Oaktree Power Opportunities Fund III Delaware, L.P. 100 % Series B-2 and B-3 Preferred Stock, Warrants at Closing Ares 100 %

Business, Basis of Presentati_2

Business, Basis of Presentation and Significant Accounting Policies (Policies)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Segment Reporting, Policy	We segregate our business into two reportable segments: the Renewables segment and the Specialty Civil segment. See Note 10. Segments
Consolidation, Policy	Principles of Consolidation The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with accounting principles generally accepted in the United States (“GAAP”) for interim financial information and with the instructions for Quarterly Reports on Form 10-Q and Rule 10-01 of Regulation S-X. Pursuant to these rules and regulations, certain information and footnote disclosures normally included in the annual audited consolidated financial statements prepared in accordance with GAAP have been condensed or omitted. Adjustments necessary to arrive at net income (loss) available for common stockholders, previously disclosed in Note 8. Earnings Per Share , have been added to the prior period presentation of the consolidated statements of operations to be comparable with the current period presentation. The unaudited condensed consolidated financial statements include the accounts of IEA and its wholly-owned domestic and foreign subsidiaries. The Company occasionally forms joint ventures with unrelated third parties for the execution of single contracts or projects. The Company assesses its joint ventures to determine if they meet the qualifications of a variable interest entity (“VIE”) in accordance with Accounting Standard Codification (“ASC”) Topic 810, Consolidation. For construction joint ventures that are not VIEs or fully consolidated but for which the Company has significant influence, the Company accounts for its interest in the joint ventures using the proportionate consolidation method, see Note 11. Joint Ventures. In the opinion of management, these financial statements reflect all adjustments (consisting of normal recurring adjustments) that are necessary to present fairly the results of operations for the interim periods presented. The results of operations for the three months ended March 31, 2021 are not necessarily indicative of the results that may be expected for the year ending December 31, 2021. These financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2020 and notes thereto included in the Company’s 2020 Annual Report on Form 10-K.
Basis of Accounting, Policy	The accompanying unaudited condensed consolidated financial statements have been prepared in accordance with GAAP.
Use of Estimates, Policy	The preparation of the condensed consolidated financial statements in conformity with GAAP requires the use of estimates and assumptions that affect the amounts reported in the condensed consolidated financial statements and the accompanying notes. Key estimates include: the recognition of revenue and project profit or loss; fair value estimates; valuations of goodwill and intangible assets; asset lives used in computing depreciation and amortization; accrued self-insured claims; other reserves and accruals; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that its estimates are reasonable when considered in conjunction with the Company’s consolidated financial position and results of operations, actual results could differ materially from those estimates.
Revenue	Revenue Recognition The Company derives revenue primarily from construction projects performed under contracts for specific projects requiring the construction and installation of an entire infrastructure system or specified units within an infrastructure system. Contracts contain multiple pricing options, such as fixed price, time and materials, or unit price. Generally, renewable energy projects are performed for private customers while Specialty Civil projects are performed for various governmental entities. Revenue derived from projects billed on a fixed-price basis totaled 96.2% and 96.0% of consolidated revenue from operations for the three months ended March 31, 2021 and 2020, respectively. Revenue and related costs for contracts billed on a time and materials basis are recognized as the services are rendered. Revenue derived from projects billed on a time and materials basis totaled 3.8% and 4.0% of consolidated revenue from operations for the three months ended March 31, 2021 and 2020, respectively. Construction contract r evenue is recognized over time using the cost-to-cost measure of progress for fixed price contracts. The cost-to-cost measure of progress best depicts the continuous transfer of control of goods or services to the customer. The contractual terms provide that the customer compensates the Company for services rendered. Contract costs include all direct materials, labor and subcontracted costs, as well as indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs and the costs of capital equipment. The cost estimation and review process for recognizing revenue over time under the cost-to-cost method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of total contract transaction price and total project costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected variable consideration are factors that influence estimates of the total contract transaction price, total costs to complete those contracts and profit recognition. Changes in these factors could result in revisions to revenue and costs of revenue in the period in which the revisions are determined on a prospective basis, which could materially affect the Company’s results of operations for that period. Provisions for losses on uncompleted contracts are recorded in the period in which such losses are determined. Performance Obligations A performance obligation is a contractual promise to transfer a distinct good or service to the customer and is the unit of account under ASC Topic 606. The transaction price of a contract is allocated to distinct performance obligations and recognized as revenue when or as the performance obligations are satisfied. The Company’s contracts often require significant integrated services and, even when delivering multiple distinct services, are generally accounted for as a single performance obligation. Contract amendments and change orders are generally not distinct from the existing contract due to the significant integrated service provided in the context of the contract and are accounted for as a modification of the existing contract and performance obligation. With the exception of certain Specialty Civil service contracts, the majority of the Company’s performance obligations are generally completed within one year. When more than one contract is entered into with a customer on or close to the same date, the Company evaluates whether those contracts should be combined and accounted for as a single contract as well as whether those contracts should be accounted for as more than one performance obligation. This evaluation requires significant judgment and is based on the facts and circumstances of the various contracts, which could change the amount of revenue and profit recognition in a given period depending upon the outcome of the evaluation. Remaining performance obligations represent the amount of unearned transaction prices for contracts, including approved and unapproved change orders. As of March 31, 2021, the amount of the Company’s remaining performance obligations was $1,627.5 million. The Company expects to recognize approximately 67.7% of its remaining performance obligations as revenue during the next twelve months. Revenue recognized from performance obligations satisfied in previous periods was $0.4 million and $(2.0) million for the three months ended March 31, 2021 and 2020, respectively. Variable Consideration Transaction pricing for the Company’s contracts may include variable consideration, such as unapproved change orders, claims, incentives and liquidated damages. Management estimates variable consideration for a performance obligation utilizing estimation methods that best predict the amount of consideration to which the Company will be entitled. Variable consideration is included in the estimated transaction price to the extent it is probable that a significant reversal of cumulative revenue recognized will not occur when the uncertainty associated with the variable consideration is resolved. Management’s estimates of variable consideration and determination of whether to include estimated amounts in transaction price are based on legal opinions, past practices with the customer, specific discussions, correspondence or preliminary negotiations with the customer and all other relevant information that is reasonably available. The effect of a change in variable consideration on the transaction price of a performance obligation is typically recognized as an adjustment to revenue on a cumulative catch-up basis. To the extent unapproved change orders, claims and liquidated damages reflected in transaction price are not resolved in the Company’s favor, or to the extent incentives reflected in transaction price are not earned, there could be reductions in, or reversals of, previously recognized revenue. As of March 31, 2021 and December 31, 2020, the Company included approximately $42.8 million and $52.6 million, respectively, of unapproved change orders and/or claims in the transaction price for certain contracts that were in the process of being resolved in the normal course of business, including through negotiation, arbitration and other proceedings. These transaction price adjustments are included within Contract Assets or Contract Liabilities as appropriate. The Company actively engages with its customers to complete the final change order approval process, and generally expects these processes to be completed within one year. Amounts ultimately realized upon final acceptance by customers could be higher or lower than such estimated amounts. Disaggregation of Revenue The following tables disaggregate revenue by customers and services performed, which the Company believes best depicts the nature, amount, timing and uncertainty of its revenue: (in thousands) Three Months Ended March 31, 2021 March 31, 2020 Renewables Segment Wind $ 146,858 $ 248,537 Solar 33,516 209 $ 180,374 $ 248,746 Specialty Civil Segment Heavy civil $ 48,871 $ 41,222 Rail 26,868 47,057 Environmental 20,299 21,138 $ 96,038 $ 109,417
Interest in Unincorporated Joint Ventures or Partnerships, Policy	Construction Joint Ventures Certain contracts are executed through joint ventures. The arrangements are often formed for the execution of single contracts or projects and allow the Company to share risks and secure specialty skills required for project execution. In accordance with ASC Topic 810, Consolidation the Company assesses its joint ventures at inception to determine if any meet the qualifications of a VIE. The Company considers a joint venture a VIE if either (a) the total equity investment is not sufficient to permit the entity to finance its activities without additional subordinated financial support, (b) characteristics of a controlling financial interest are missing (either the ability to make decisions through voting or other rights, the obligation to absorb the expected losses of the entity or the right to receive the expected residual returns of the entity), or (c) the voting rights of the equity holders are not proportional to their obligations to absorb the expected losses of the entity and/or their rights to receive the expected residual returns of the entity and substantially all of the entity’s activities either involve or are conducted on behalf of an investor that has disproportionately few voting rights. Upon the occurrence of certain events outlined in ASC 810, the Company reassesses its initial determination of whether the joint venture is a VIE. The Company also evaluates whether it is the primary beneficiary of each VIE and consolidates the VIE if the Company has both (a) the power to direct the economically significant activities of the entity and (b) the obligation to absorb losses of, or the right to receive benefits from, the entity that could potentially be significant to the VIE. The Company considers the contractual agreements that define the ownership structure, distribution of profits and losses, risks, responsibilities, indebtedness, voting rights and board representation of the respective parties in determining whether it qualifies as the primary beneficiary. The Company also considers all parties that have direct or implicit variable interests when determining whether it is the primary beneficiary. When the Company is determined to be the primary beneficiary, the VIE is consolidated. In accordance with ASC 810, management’s assessment of whether the Company is the primary beneficiary of a VIE is performed continuously. Construction joint ventures that do not involve a VIE, or for which the Company is not the primary beneficiary, are evaluated for consolidation under the voting interest model that considers whether the Company owns or controls more than 50% of the voting interest in the joint venture. For construction joint ventures that are not consolidated but for which the Company has significant influence, the Company accounts for its interest in the joint ventures using the proportionate consolidation method, whereby the Company’s proportionate share of the joint ventures’ assets, liabilities, revenue and cost of operations are included in the appropriate classifications in the Company’s consolidated financial statements. See Note 11. Joint Ventures for additional discussion regarding joint ventures.
New Accounting Pronouncements, Policy	Recently Adopted Accounting Standards - Guidance Adopted in 2020 In December 2019, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update (“ASU”) No. 2019-12, “Income Taxes (Topic 740): Simplifying the Accounting for Income Taxes,” which removes certain exceptions to the general principles in Topic 740 and also clarifies and amends existing guidance to improve consistent application. This ASU is effective for fiscal years beginning after December 15, 2020, and interim periods within those fiscal years. Depending on the amendment, adoption may be applied on the retrospective, modified retrospective, or prospective basis. The Company adopted the standard on January 1, 2021 on a prospective basis, which did not have an impact on our disclosures for income taxes. Recently Issued Accounting Standards Not Yet Adopted In June 2016, the FASB issued ASU 2016-13, “Financial Instruments—Credit Losses (Topic 326): Measurement of Credit Losses on Financial Instruments,” which introduced an expected credit loss methodology for the measurement and recognition of credit losses on most financial assets, including trade accounts receivables. The expected credit loss methodology under ASU 2016-13 is based on historical experience, current conditions and reasonable and supportable forecasts, and replaces the probable/incurred loss model for measuring and recognizing expected losses under current GAAP. The ASU also requires disclosure of information regarding how a company developed its allowance, including changes in the factors that influenced management’s estimate of expected credit losses and the reasons for those changes. The ASU and its related clarifying updates are effective for smaller reporting companies for fiscal years beginning after December 15, 2022, and interim periods within those fiscal years, with early adoption permitted. The Company is still evaluating the new standard but do not expect it to have a material impact on our estimate of the allowance for uncollectable accounts. Management has evaluated other recently issued accounting pronouncements and does not believe that they will have a significant impact on the financial statements and related disclosures.

Business, Basis of Presentati_3

Business, Basis of Presentation and Significant Accounting Policies (Tables)	3 Months Ended
	Mar. 31, 2021
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Disaggregation of Revenue	The following tables disaggregate revenue by customers and services performed, which the Company believes best depicts the nature, amount, timing and uncertainty of its revenue: (in thousands) Three Months Ended March 31, 2021 March 31, 2020 Renewables Segment Wind $ 146,858 $ 248,537 Solar 33,516 209 $ 180,374 $ 248,746 Specialty Civil Segment Heavy civil $ 48,871 $ 41,222 Rail 26,868 47,057 Environmental 20,299 21,138 $ 96,038 $ 109,417
Schedule of revenue and accounts receivable concentrations, net of allowances	The Company had the following approximate revenue and accounts receivable concentrations, net of allowances, for the periods ended: Revenue % Three Months Ended Accounts Receivable % March 31, 2021 March 31, 2020 March 31, 2021 December 31, 2020 Company A (Renewables Segment) * 11.5 % * * Company B (Renewables Segment) * 11.1 % * * * Amount was not above 10% threshold

Contract Assets and Liabiliti_2

Contract Assets and Liabilities (Tables)	3 Months Ended
	Mar. 31, 2021
Contractors [Abstract]
Contract Assets and Contract Liabilities	(in thousands) March 31, 2021 December 31, 2020 Costs and estimated earnings in excess of billings on uncompleted contracts $ 60,132 $ 51,367 Retainage receivable 86,564 93,816 $ 146,696 $ 145,183 Contract liabilities consist of the following: (in thousands) March 31, 2021 December 31, 2020 Billings in excess of costs and estimated earnings on uncompleted contracts $ 141,231 $ 117,641 Loss on contracts in progress 189 594 $ 141,420 $ 118,235
Accounts Receivable, Allowance for Credit Loss	Activity in the allowance for doubtful accounts for the periods indicated was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Allowance for doubtful accounts at beginning of period $ — $ 75 Plus: provision for (reduction in) allowance — 14 Less: write-offs, net of recoveries — — Allowance for doubtful accounts at period end $ — $ 89

Property, plant and equipment_2

Property, plant and equipment, net (Tables)	3 Months Ended
	Mar. 31, 2021
Property, Plant and Equipment [Abstract]
Schedule of property plant and equipment	Property, plant and equipment consisted of the following: (in thousands) March 31, 2021 December 31, 2020 Buildings and leasehold improvements $ 4,890 $ 4,402 Land 17,600 17,600 Construction equipment 197,057 192,402 Office equipment, furniture and fixtures 3,637 3,620 Vehicles 7,426 7,326 230,610 225,350 Accumulated depreciation (103,346) (94,604) Property, plant and equipment, net $ 127,264 $ 130,746

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	3 Months Ended
	Mar. 31, 2021
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	The following table provides the changes in the carrying amount of goodwill, by segment: (in thousands) Renewables Specialty Civil Total January 1, 2020 $ 3,020 $ 34,353 $ 37,373 Adjustments — — — December 31, 2020 $ 3,020 $ 34,353 $ 37,373 Adjustments — — — March 31, 2021 $ 3,020 $ 34,353 $ 37,373
Schedule of Finite-Lived Intangible Assets	Intangible assets consisted of the following as of the dates indicated: March 31, 2021 December 31, 2020 ($ in thousands) Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Life Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Remaining Life Customer relationships $ 26,500 $ (9,427) $ 17,073 4.75 years $ 26,500 $ (8,481) $ 18,019 5 years Trade name 13,400 (6,655) 6,745 2.75 years 13,400 (5,985) 7,415 3 years $ 53,800 $ (29,982) $ 23,818 $ 53,800 $ (28,366) $ 25,434
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense	The following table provides the annual intangible amortization expense currently expected to be recognized for the years 2021 through 2025: (in thousands) Remainder of 2021 2022 2023 2024 2025 Amortization expense $ 4,849 $ 6,466 $ 5,841 $ 3,785 $ 2,876

Fair value of financial instr_2

Fair value of financial instruments (Tables)	3 Months Ended
	Mar. 31, 2021
Fair Value Disclosures [Abstract]
Schedule of fair value of liabilities measured on recurring basis	The following table sets forth information regarding the Company's liabilities measured at fair value on a recurring basis: March 31, 2021 December 31, 2020 (in thousands) Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Liabilities Private warrants $ — $ 1,000 $ — $ 1,000 $ — $ — $ — $ — Series B Preferred Stock - Anti-dilution warrants — — 8,100 8,100 — — 8,800 8,800 Series B-1 Preferred Stock - Performance warrants — — 400 400 — — 400 400 Total liabilities $ — $ 1,000 $ 8,500 $ 9,500 $ — $ — $ 9,200 $ 9,200
Schedule of reconciliation of fair value unobservable liabilities measured on recurring basis	The following is a reconciliation of the beginning and ending balances of recurring fair value measurements using Level 3 inputs: (in thousands) Series B Preferred Stock - Anti-dilution warrants Series B-1 Preferred Stock - Performance warrants Beginning Balance, December 31, 2020 $ 8,800 $ 400 Fair value adjustment - loss (gain) recognized in other income (700) — Ending Balance, March 31, 2021 $ 8,100 $ 400

Debt and Series B Preferred S_2

Debt and Series B Preferred Stock (Tables)	3 Months Ended
	Mar. 31, 2021
Debt Disclosure [Abstract]
Schedule of debt	Debt consisted of the following obligations as of: (in thousands) March 31, 2021 December 31, 2020 Term loan $ 173,345 $ 173,345 Commercial equipment notes 4,897 5,582 Total principal due for long-term debt 178,242 178,927 Unamortized debt discount and issuance costs (15,634) (17,196) Less: Current portion of long-term debt (2,379) (2,506) Long-term debt, less current portion $ 160,229 $ 159,225 Debt - Series B Preferred Stock $ 185,998 $ 185,396 Unamortized debt discount and issuance costs (10,834) (11,528) Long-term Series B Preferred Stock $ 175,164 $ 173,868
Contractual maturities of debt and capital lease obligations	Contractual Maturities Contractual maturities of the Company's outstanding principal on debt obligations as of March 31, 2021: (in thousands) Maturities Remainder of 2021 $ 1,821 2022 16,938 2023 29,986 2024 129,368 2025 129 Thereafter — Total contractual maturities $ 178,242

Commitments and contingencies (

Commitments and contingencies (Tables)	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Schedule of Future Minimum Lease Payments for Capital Leases	The future minimum payments of finance lease obligations are as follows: (in thousands) Remainder of 2021 $ 19,994 2022 21,996 2023 7,267 2024 3,264 2025 1,799 Thereafter 78 Future minimum lease payments 54,398 Less: Amount representing interest (2,617) Present value of minimum lease payments 51,781 Less: Current portion of finance lease obligations 24,728 Finance lease obligations, less current portion $ 27,053
Schedule of Future Minimum Rental Payments for Operating Leases	The future minimum payments under non-cancelable operating leases are as follows: (in thousands) Remainder of 2021 $ 8,435 2022 9,753 2023 7,347 2024 3,532 2025 1,751 Thereafter 18,899 Future minimum lease payments 49,717 Less: Amount representing interest (13,202) Present value of minimum lease payments 36,515 Less: Current portion of operating lease obligations 8,779 Operating lease obligations, less current portion $ 27,736
Schedule of Additional Lease Information	Lease Information Three Months Ended March 31, 2021 March 31, 2020 Finance Lease cost: Amortization of right-of-use assets $ 5,835 $ 5,697 Interest on lease liabilities 817 1,186 Operating lease cost 3,394 3,478 Short-term lease cost 23,604 21,635 Variable lease cost 1,247 960 Sublease Income (33) (33) Total lease cost $ 34,864 $ 32,923 Other information: Cash paid for amounts included in the measurement of lease liabilities: Operating cash flows from finance leases $ 817 $ 1,186 Operating cash flows from operating leases $ 3,245 $ 3,342 Weighted-average remaining lease term - finance leases 2.41 years 2.73 years Weighted-average remaining lease term - operating leases 8.17 years 8.02 years Weighted-average discount rate - finance leases 6.18 % 6.49 % Weighted-average discount rate - operating leases 7.00 % 7.14 %

Earnings per share (Tables)

Earnings per share (Tables)	3 Months Ended
	Mar. 31, 2021
Earnings Per Share [Abstract]
Schedule of basic and diluted EPS	The calculations of basic and diluted EPS, are as follows: Three Months Ended March 31, ($ in thousands, except per share data) 2021 2020 Numerator: Net loss $ (20,434) $ (12,743) Less: Convertible Preferred Stock dividends (656) (766) Net loss available to common stockholders (21,090) (13,509) Denominator: Weighted average common shares outstanding - basic and diluted 23,057,731 20,522,216 Anti-dilutive: Convertible Series A Preferred 1,628,269 6,553,041 Merger Warrants (1) 3,074,481 — Series B Preferred - Warrants (2) 7,684,057 7,675,325 Options (3) 426,824 — RSUs (3) 1,958,045 1,456,359 Basic EPS (0.91) (0.66) Diluted EPS (0.91) (0.66) (1) As of March 31, 2020, Merger Warrants to purchase 8,480,000 shares of common stock at $11.50 per share were not considered as dilutive as the warrants’ exercise price was not greater than the average market price of the common stock during the period. As of March 31, 2021, these warrants were calculated using the treasury stock method and were anti-dilutive. (2) Series B Preferred - Warrants are considered as participating securities because the holders are entitled to participate in any distributions similar to that of common shareholders.

Segments (Tables)

Segments (Tables)	3 Months Ended
	Mar. 31, 2021
Segments [Abstract]
Reconciliation of Revenue from Segments to Consolidated	Segment Revenue Revenue by segment was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Segment Revenue % of Total Revenue Revenue % of Total Revenue Renewables $ 180,374 65.3 % $ 248,746 69.5 % Specialty Civil 96,038 34.7 % 109,417 30.5 % Total revenue $ 276,412 100.0 % $ 358,163 100.0 %
Reconciliation of Other Significant Reconciling Items from Segments to Consolidated	Segment Gross Profit Gross profit by segment was as follows: Three Months Ended March 31, (in thousands) 2021 2020 Segment Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Renewables $ 12,180 6.8 % $ 25,829 10.4 % Specialty Civil 4,361 4.5 % 7,212 6.6 % Total gross profit $ 16,541 6.0 % $ 33,041 9.2 %

Investments, Equity Method an_2

Investments, Equity Method and Joint Ventures (Tables)	3 Months Ended
	Mar. 31, 2021
Equity Method Investments and Joint Ventures [Abstract]
Schedule of Operating Activities of Joint Ventures	As of March 31, 2021, the Company did not have any VIEs but did have one joint venture that used the proportionate consolidation method at 25% ownership. The following balances were included in the condensed consolidated financial statements: (in thousands) March 31, 2021 Assets Cash $ 5,455 Accounts receivable 3,963 Contract assets 1,446 Liabilities Accounts payable $ 3,461 Contract liabilities 7,403 Three Months Ended March 31, 2021 Revenue $ 4,501 Cost of revenue 4,501

Related party transactions (Tab

Related party transactions (Tables)	3 Months Ended
	Mar. 31, 2021
Related Party Transactions [Abstract]
Schedule of related party shareholders	Related Party Shareholders Type of Equity Holder Ownership Percentage Series A Preferred Stock and Series A Conversion Warrants Ares 100 % Series B-1 Preferred Stock, Performance Warrants, Warrants at Closing (initial amount issued) Ares 100 % Series B-1 Warrants at Closing (initial amount issued), Exchange Warrants Oaktree Power Opportunities Fund III Delaware, L.P. 100 % Series B-2 and B-3 Preferred Stock, Warrants at Closing Ares 100 %

Business, Basis of Presentati_4

Business, Basis of Presentation and Significant Accounting Policies Disaggregation of Revenue (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)	Mar. 31, 2020USD ($)
Disaggregation of Revenue [Line Items]
Number of Reportable Segments	2
Revenue	$ 276,412	$ 358,163
Wind Revenue
Disaggregation of Revenue [Line Items]
Revenue	146,858	248,537
Solar Revenue
Disaggregation of Revenue [Line Items]
Revenue	33,516	209
Heavy Civil Revenue
Disaggregation of Revenue [Line Items]
Revenue	48,871	41,222
Rail Construction Revenue
Disaggregation of Revenue [Line Items]
Revenue	26,868	47,057
Environmental Revenue
Disaggregation of Revenue [Line Items]
Revenue	20,299	21,138
Renewables Segment
Disaggregation of Revenue [Line Items]
Revenue	180,374	248,746
Specialty Civil Segment
Disaggregation of Revenue [Line Items]
Revenue	$ 96,038	$ 109,417

Business, Basis of Presentati_5

Business, Basis of Presentation and Significant Accounting Policies Schedule of concentrations for revenue and accounts receivable (Details) - Product Concentration Risk - Revenue Benchmark	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Fixed-price Contract
Concentration Risk [Line Items]
Concentration Risk, Percentage	96.20%	96.00%
Time-and-materials Contract
Concentration Risk [Line Items]
Concentration Risk, Percentage	3.80%	4.00%
Concentration Company A
Concentration Risk [Line Items]
Concentration Risk, Percentage		11.50%
Concentration Company B
Concentration Risk [Line Items]
Concentration Risk, Percentage		11.10%

Business, Basis of Presentati_6

Business, Basis of Presentation and Significant Accounting Policies Revenue 606 (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Amount	$ 1,627,500
Revenue, Remaining Performance Obligation, Percentage	67.70%
Contract with Customer, Performance Obligation Satisfied in Previous Period	$ 400	$ (2,000)
Contract with Customer, Revenue Recognized, Related to Unapproved Change Orders and Claims	$ 42,800		$ 52,600
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Start Date [Axis]: 2021-04-01
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction [Line Items]
Revenue, Remaining Performance Obligation, Expected Timing of Satisfaction, Period	12 months

Contract Assets and Liabiliti_3

Contract Assets and Liabilities Contract Assets and Contract Liabilities (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Contractors [Abstract]
Unbilled Contracts Receivable	$ 60,132	$ 51,367
Construction Contractor, Receivable, Retainage	86,564	93,816
Contract Assets	146,696	145,183
Deferred Revenue	141,231	117,641
Provision for Loss on Contracts	189	594
Contract Liabilities	141,420	$ 118,235
Contract with Customer, Liability, Revenue Recognized	$ 87,800

Contract Assets and Liabiliti_4

Contract Assets and Liabilities Activity in allowance for doubtful accounts (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Receivables [Abstract]
Accounts Receivable, Allowance for Credit Loss, Beginning of Period	$ 0	$ 75
Accounts Receivable, Allowance for Credit Loss, Writeoff	0	14
Accounts Receivable, Credit Loss Expense (Reversal)	0	0
Accounts Receivable, Allowance for Credit Loss, End of Period	$ 0	$ 89

Property, plant and equipment_3

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 230,610		$ 225,350
Accumulated depreciation	(103,346)		(94,604)
Property, plant and equipment, net	127,264		130,746
Depreciation expense	9,183	$ 8,516
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	4,890		4,402
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	17,600		17,600
Construction equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	197,057		192,402
Office equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,637		3,620
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 7,426		$ 7,326

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 37,373	$ 37,373
Goodwill, Period Increase (Decrease)	0	0
Goodwill, Ending Balance	37,373	37,373
Renewables Segment
Goodwill [Line Items]
Goodwill, Beginning Balance	3,020	3,020
Goodwill, Period Increase (Decrease)	0	0
Goodwill, Ending Balance	3,020	3,020
Specialty Civil Segment
Goodwill [Line Items]
Goodwill, Beginning Balance	34,353	34,353
Goodwill, Period Increase (Decrease)	0	0
Goodwill, Ending Balance	$ 34,353	$ 34,353

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets, net Schedule of intangible assets (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 53,800		$ 53,800
Accumulated Amortization	(29,982)		(28,366)
Net Book Value	23,818		25,434
Amortization of Intangible Assets	1,600	$ 3,400
Customer relationships
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	26,500		26,500
Accumulated Amortization	(9,427)		(8,481)
Net Book Value	$ 17,073		18,019
Weighted Average Useful Life	4 years 9 months	5 years
Trade name
Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 13,400		13,400
Accumulated Amortization	(6,655)		(5,985)
Net Book Value	$ 6,745		$ 7,415
Weighted Average Useful Life	2 years 9 months	3 years

Goodwill and Intangible Asset_5

Goodwill and Intangible Assets, net Schedule of annual expected amortization expense (Details) $ in Thousands	Mar. 31, 2021USD ($)
Finite-Lived Intangible Assets [Line Items]
Remainder of 2021	$ 4,849
2022	6,466
2023	5,841
2024	3,785
2025	$ 2,876

Fair value of financial instr_3

Fair value of financial instruments - Fair Value Liabilities Measured on Recurring Basis (Details) - Recurring - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	$ 9,500	$ 9,200
Merger Warrants - Private
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	1,000	0
Series B Preferred - Series A Conversion Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	8,100	8,800
Series B-1 Preferred Stock 6% Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	400	400
Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Merger Warrants - Private
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B Preferred - Series A Conversion Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B-1 Preferred Stock 6% Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	1,000	0
Significant Other Observable Inputs (Level 2) | Merger Warrants - Private
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	1,000	0
Significant Other Observable Inputs (Level 2) | Series B Preferred - Series A Conversion Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Significant Other Observable Inputs (Level 2) | Series B-1 Preferred Stock 6% Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	8,500	9,200
Significant Unobservable Inputs (Level 3) | Merger Warrants - Private
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	0	0
Significant Unobservable Inputs (Level 3) | Series B Preferred - Series A Conversion Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	8,100	8,800
Significant Unobservable Inputs (Level 3) | Series B-1 Preferred Stock 6% Warrants
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Obligations, Fair Value Disclosure	$ 400	$ 400

Fair value of financial instr_4

Fair value of financial instruments - Reconciliation of Level 3 Inputs (Details) $ in Thousands	3 Months Ended
	Mar. 31, 2021USD ($)
Series B Preferred - Series A Conversion Warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance, December 31, 2020	$ 8,800
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	(700)
Ending Balance, March 31, 2021	8,100
Series B-1 Preferred Stock 6% Warrants
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance, December 31, 2020	400
Fair Value, Measurement with Unobservable Inputs Reconciliation, Recurring Basis, Liability, Gain (Loss) Included in Earnings	0
Ending Balance, March 31, 2021	$ 400

Fair value of financial instr_5

Fair value of financial instruments - Fair Value (Details) shares in Thousands	Mar. 31, 2021shares	May 20, 2019numberOfDays$ / shares
Series B Preferred Stock Warrants at closing
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock Warrant Exercise Price | $ / shares		$ 0.0001
30-DAY VWAP | numberOfDays		30
Merger Warrants - Private
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Merger Warrants - Private | shares	295

Debt and Series B Preferred S_3

Debt and Series B Preferred Stock - Long-Term Debt (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Debt Instrument [Line Items]
Total principal due for long-term debt	$ 178,242	$ 178,927
Debt Issuance Costs, Net	(15,634)	(17,196)
Long-term Debt, Current Maturities	(2,379)	(2,506)
Long-term debt, less current portion	160,229	159,225
Debt - Series B Preferred Stock	175,164	173,868
Term Loan
Debt Instrument [Line Items]
Total principal due for long-term debt	173,345	173,345
Series B Preferred Stock Liability
Debt Instrument [Line Items]
Total principal due for long-term debt	185,998	185,396
Debt Issuance Costs, Net	(10,834)	(11,528)
Commercial equipment notes
Debt Instrument [Line Items]
Total principal due for long-term debt	$ 4,897	$ 5,582

Debt and Series B Preferred S_4

Debt and Series B Preferred Stock- Narrative (Details)	3 Months Ended
	Mar. 31, 2021	Dec. 31, 2020
Debt Covenant Period, Period Three | Third A&R Credit Agreement
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	2.75
Debt Covenant Period, Period Four | Third A&R Credit Agreement
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	2.25
Term Loan
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	6.95%	7.00%

Debt and Series B Preferred S_5

Debt and Series B Preferred Stock - Series B Preferred Stock (Details) - Series B Preferred Stock - USD ($) $ in Thousands	Mar. 31, 2021	Nov. 14, 2019
Preferred Debt Details [Line Items]
Dividend Rate after 1.5:1.0 leverage		12.00%
Ratio Net Leverage Ratio for Deleveraging Event		1.50
Preferred Stock Paid In Kind Dividend Rate		15.00%
Series B Cash Dividend Rate after Deleveraging		13.50%
Dividends Payable	$ 18,300

Debt and Series B Preferred S_6

Debt and Series B Preferred Stock- Long Term Debt Obligations (Details) $ in Thousands	Mar. 31, 2021USD ($)
Debt Disclosure [Abstract]
Remainder of 2021	$ 1,821
2022	16,938
2023	29,986
2024	129,368
2025	129
Thereafter	0
Contractual Obligation	$ 178,242

Commitments and contingencies -

Commitments and contingencies - Lease Narrative (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosure [Abstract]
Finance Lease, Liability	$ 51,781	$ 57,600
Finance leased assets, gross	129,700	128,000
Finance leased assets, accumulated depreciation	(60,700)	(55,100)
Finance leased assets, net	69,000	72,900
Operating Lease, Liability	36,515	38,000
Operating Lease, Right-of-Use Asset	34,994	$ 36,461
Other Commitments, Future Minimum Payments, Remainder of Fiscal Year	$ 3,200

Commitments and contingencies F

Commitments and contingencies Future minimum payments of finance leases (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosures [Abstract]
Remainder of 2021	$ 19,994
2022	21,996
2023	7,267
2024	3,264
2025	1,799
Thereafter	78
Finance minimum lease payments	54,398
Less: Amount representing interest	(2,617)
Present Value of Minimum Lease Payments	51,781	$ 57,600
Current portion of finance lease obligations	24,728	25,423
Finance lease obligations, less current portion	$ 27,053	$ 32,146

Commitments and contingencies_2

Commitments and contingencies Future mimum payments of operating leases (Details) - USD ($) $ in Thousands	Mar. 31, 2021	Dec. 31, 2020
Commitments and Contingencies Disclosures [Abstract]
Remainder of 2021	$ 8,435
2022	9,753
2023	7,347
2024	3,532
2025	1,751
Thereafter	18,899
Lessee, Operating Lease, Liability, Payments, Due	49,717
Operating Leases, Future Minimum Payments, Interest Included in Payments	(13,202)
Operating Lease, Liability	36,515	$ 38,000
Operating Lease, Liability, Current	8,779	8,835
Operating Lease, Liability, Noncurrent	$ 27,736	$ 29,154

Commitments and contingencies S

Commitments and contingencies Schedule of Additional Lease Information (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Additional Lease Information [Abstract]
Finance Lease, Right-of-Use Asset, Amortization	$ 5,835	$ 5,697
Finance Lease, Interest Expense	817	1,186
Operating Leases, Rent Expense, Net	3,394	3,478
Short-term Lease, Cost	23,604	21,635
Variable Lease, Cost	1,247	960
Sublease Income	(33)	(33)
Lease, Cost	34,864	32,923
Operating Cashflow Finance Leases	817	1,186
Operating cashflow from operating leases	$ 3,245	$ 3,342
Finance Lease, Weighted Average Remaining Lease Term	2 years 4 months 28 days	2 years 8 months 23 days
Operating Lease, Weighted Average Remaining Lease Term	8 years 2 months 1 day	8 years 7 days
Finance Lease, Weighted Average Discount Rate, Percent	6.18%	6.49%
Operating Lease, Weighted Average Discount Rate, Percent	7.00%	7.14%

Other Commitments and contingen

Other Commitments and contingencies (Details) - USD ($) $ in Millions	Mar. 31, 2021	Dec. 31, 2020
Other Commitments [Line Items]
Letters of Credit Outstanding, Amount	$ 22	$ 7.8
Special Assessment Bond	$ 3,000	$ 2,800

Earnings per share - Basic and

Earnings per share - Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net loss	$ (20,434)	$ (12,743)
Less: Convertible Preferred Stock dividends	(656)	(766)
Net loss available to common stockholders	$ (21,090)	$ (13,509)
Denominator:
Weighted Average Number of Shares Outstanding, Basic and Diluted	23,057,731	20,522,216
Basic EPS (in dollars per share)	$ (0.91)	$ (0.66)
Diluted EPS (in dollars per share)	$ (0.91)	$ (0.66)
Redeemable Preferred Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	1,628,269	6,553,041
Merger Warrants
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	3,074,481	0
Antidilutive securities excluded from computation of earnings per share, amount		8,480,000
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 11.50	$ 11.50
Warrants for Common Stock
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	7,684,057	7,675,325
Equity Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	426,824	0
Restricted Stock Units (RSUs)
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	1,958,045	1,456,359
Antidilutive securities excluded from computation of earnings per share, amount		141,248
Share-based Payment Arrangement, Option
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount		591,860

Earnings per share - Narrative

Earnings per share - Narrative (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020	May 20, 2019
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	17,483		17,483
Preferred stock, par value (in dollars per share)	$ 0.0001		$ 0.0001
Share-based compensation expense	$ 727,000	$ 1,113,000
Merger Warrants
Class of Stock [Line Items]
Merger Warrants	16,925,160
Class of Warrant or Right, Exercise Price of Warrants or Rights	$ 11.50	$ 11.50
Merger Warrants - Private	295,000
Series B Preferred Stock Warrants at closing
Class of Stock [Line Items]
Anti-dilution Warrants	495,762
Exercise price of securities excluded at closing				$ 11.50
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares)	17,483
Preferred stock, par value (in dollars per share)	$ 1,000
Preferred stock, dividend rate thereafter	10.00%
Series A Preferred PIK Dividend Rate 18 mos	12.00%
Default Rate for Uncured Dividends	2.00%
Dividends Payable	$ 5,000,000

Income taxes (Details)

Income taxes (Details) - USD ($)	3 Months Ended		12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Income Tax Contingency [Line Items]
Statutory federal tax rate	21.00%
Effective tax rates	10.50%	6.40%
Increase (decrease) in uncertain tax positions	$ 0
Tax Cuts and Jobs Act, Change in Tax Rate, Deferred Tax Liability, Income Tax Benefit			$ 13,600,000
Minimum
Income Tax Contingency [Line Items]
State tax rate	0.80%
Maximum
Income Tax Contingency [Line Items]
State tax rate	12.00%

Segments (Details)

Segments (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Revenue	$ 276,412	$ 358,163
Segment revenue as a percentage of total revenue	100.00%	100.00%
Gross Profit	$ 16,541	$ 33,041
Gross Profit Margin	6.00%	9.20%
Renewables Segment
Segment Reporting Information [Line Items]
Revenue	$ 180,374	$ 248,746
Segment revenue as a percentage of total revenue	65.30%	69.50%
Gross Profit	$ 12,180	$ 25,829
Gross Profit Margin	6.80%	10.40%
Specialty Civil Segment
Segment Reporting Information [Line Items]
Revenue	$ 96,038	$ 109,417
Segment revenue as a percentage of total revenue	34.70%	30.50%
Gross Profit	$ 4,361	$ 7,212
Gross Profit Margin	4.50%	6.60%

Investments, Equity Method an_3

Investments, Equity Method and Joint Ventures (Details) - USD ($)	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Dec. 31, 2020
Schedule of Operating Activities of Joint Ventures [Line Items]
Cash and cash equivalents	$ 95,173,000		$ 164,041,000
Accounts receivable, net	171,306,000		163,793,000
Contract Assets	146,696,000		145,183,000
Accounts Payable, Current	86,826,000		104,960,000
Contract Liabilities	141,420,000		$ 118,235,000
Revenue	276,412,000	$ 358,163,000
Cost of revenue	259,871,000	$ 325,122,000
Noncontrolling Interest in Joint Ventures	0.25
Rail Joint Venture Member
Schedule of Operating Activities of Joint Ventures [Line Items]
Cash and cash equivalents	5,455,000
Accounts receivable, net	3,963,000
Contract Assets	1,446,000
Accounts Payable, Current	3,461,000
Contract Liabilities	7,403,000
Revenue	4,501,000
Cost of revenue	$ 4,501,000

Related party transactions (Det

Related party transactions (Details)	Mar. 31, 2021shares
Related Party Transaction [Line Items]
Series B Preferred Stock	350
Series B Preferred Stock | Ares
Related Party Transaction [Line Items]
Series B Preferred Equity Agreement - All Equity Ares	100.00%
Series B Preferred Stock | Oaktree
Related Party Transaction [Line Items]
Series B Preferred Equity Agreement - All Equity Oaktree	100.00%
Series B-2 Preferred Stock | Ares
Related Party Transaction [Line Items]
Series B Preferred Equity Agreement - All Equity Ares	100.00%
Series A Preferred Stock | Ares
Related Party Transaction [Line Items]
Series A Preferred Stock and Series A Conversion Warrants	100.00%