Infrastructure and Energy Alternatives (IEA) 10-Q 12 Nov 19 2019 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2019	Nov. 12, 2019
Document and Entity Information [Abstract]
Entity Registrant Name	Infrastructure & Energy Alternatives, Inc.
Entity Central Index Key	0001652362
Document Type	10-Q
Document Period End Date	Sep. 30, 2019
Document Fiscal Year Focus	2019
Amendment Flag	false
Document Fiscal Period Focus	Q3
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Small Business	true
Entity Current Reporting Status	Yes
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		22,252,489

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Current assets:
Cash and cash equivalents	$ 43,174	$ 71,311
Accounts receivable, net	244,465	225,366
Costs and estimated earnings in excess of billings on uncompleted contracts	109,540	47,121
Prepaid expenses and other current assets	18,533	12,864
Total current assets	415,712	356,662
Property, plant and equipment, net	151,784	176,178
Goodwill	37,373	40,257
Intangible Assets, Net (Excluding Goodwill)	40,626	50,874
Company-owned life insurance	3,935	3,854
Other assets	550	188
Deferred income taxes	15,847	11,215
Total assets	665,827	639,228
Current liabilities:
Accounts payable	126,484	158,075
Accrued Liabilities, Current	131,170	94,059
Billings in excess of costs and estimated earnings on uncompleted contracts	71,814	62,234
Current portion of capital lease obligations	24,640	17,615
Current portion of long-term debt	31,119	32,580
Total current liabilities	385,227	364,563
Capital lease obligations, net of current maturities	49,268	45,912
Long-term Debt	226,606	295,727
Debt - Series B Preferred Stock	76,766	0
Series B Preferred Stock - warrant obligations	4,223	0
Deferred compensation	8,077	6,157
Contingent consideration	0	23,082
Total liabilities	750,167	735,441
Commitments and contingencies:
Series A Preferred Stock, par value, $0.0001 per share; 1,000,000 shares authorized; 34,965 shares and 34,965 shares issued and outstanding at September 30, 2019 and December 31, 2018, respectively	34,965	34,965
Stockholders' equity (deficit):
Common stock, par value, $0.0001 per share; 100,000,000 shares authorized; 20,460,533 and 22,155,271 shares issued and 20,446,811 and 22,155,271 outstanding at September 30, 2019 and December 31, 2018, respectively	2	2
Treasury Stock, 13,722 shares at cost	(76)	0
Additional paid in capital	18,018	4,751
Retained earnings (deficit)	(137,249)	(135,931)
Total stockholders' equity (deficit)	(119,305)	(131,178)
Total liabilities and stockholders' equity (deficit)	$ 665,827	$ 639,228

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2019	Dec. 31, 2018
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)	34,965	34,965
Preferred stock, shares outstanding	34,965	34,965
Common stock, par value (in dollars per share)	$ 0.0001	$ 0.0001
Common stock, shares authorized	100,000,000	100,000,000
Common stock, shares, issued	20,460,533	22,155,271
Common stock, shares, outstanding	20,446,811	22,155,271
Treasury Stock, Shares	13,722

Condensed Consolidated Statemen

Condensed Consolidated Statement of Operations - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Revenue	$ 422,022	$ 279,279	$ 940,793	$ 503,487
Cost of revenue	369,152	252,271	849,728	462,765
Gross profit	52,870	27,008	91,065	40,722
Selling, general and administrative expenses	31,313	16,964	84,945	43,122
Income (loss) from operations	21,557	10,044	6,120	(2,400)
Other income (expense), net:
Interest expense, net	(13,959)	(1,579)	(35,822)	(3,960)
Other income (expense)	4,455	(1,859)	22,557	(1,848)
Income (loss) before benefit for income taxes	12,053	6,606	(7,145)	(8,208)
Benefit (provision) for income taxes	556	(870)	3,073	1,467
Net income (loss)	$ 12,609	$ 5,736	$ (4,072)	$ (6,741)
Earnings Per Share, Basic	$ 0.37	$ 0.24	$ (1.44)	$ (0.36)
Earnings Per Share, Diluted	$ 0.24	$ 0.23	$ (1.44)	$ (0.36)
Weighted Average Number of Shares Outstanding, Basic	20,446,811	21,577,650	20,425,801	21,577,650
Weighted Average Number of Shares Outstanding, Diluted	35,419,432	25,100,088	20,425,801	21,577,650

Condensed Statements of Stockho

Condensed Statements of Stockholders Equity (Deficit) Statement - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Common Stock [Member]Common Stock [Member]	Additional Paid-in Capital [Member]	Additional Paid-in Capital [Member]Common Stock [Member]	Treasury Stock [Member]	Treasury Stock [Member]Treasury Stock [Member]	Retained Earnings [Member]	Retained Earnings [Member]Preferred Stock [Member]
Shares, Issued		21,578
Stockholders' Equity Attributable to Parent	$ (10,019)	$ 2		$ 0		$ 0		$ (10,021)
Net loss	(17,392)							(17,392)
Stock Issued During Period, Value, New Issues	(34,965)								$ (34,965)
Adjustments to Additional Paid in Capital, Contingent Consideration	(69,373)							(69,373)
Adjustments to Additional Paid in Capital, Business Combination	(22,973)							(22,973)
Net loss	(6,741)
Shares, Issued		21,578
Stockholders' Equity Attributable to Parent	(154,722)	$ 2		0		0		(154,724)
Net loss	4,915							4,915
Adjustments to Additional Paid in Capital, Business Combination	(2,843)							(2,843)
Dividends, Preferred Stock, Stock	(548)							(548)
Shares, Issued		21,578
Stockholders' Equity Attributable to Parent	(153,198)	$ 2		0		$ 0		(153,200)
Net loss	5,736							5,736
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	500			500
Dividends, Preferred Stock, Stock	(524)							(524)
Shares, Issued		21,578				0
Stockholders' Equity Attributable to Parent	(147,486)	$ 2		500		$ 0		(147,988)
Shares, Issued		22,155
Stockholders' Equity Attributable to Parent	(131,178)	$ 2		4,751		$ 0		(135,931)
Net loss	(22,889)							(22,889)
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	1,040			1,040
Stock Issued During Period, Shares, New Issues			111
Stock Issued During Period, Value, New Issues	159	$ 0			$ 235
Adjustments to Additional Paid in Capital, Business Combination	(2,754)							(2,754)
Treasury Stock, Shares							(14)
Dividends, Preferred Stock, Stock	(525)			(525)
Net loss	(4,072)
Shares, Issued		22,266				(14)
Stockholders' Equity Attributable to Parent	(150,639)	$ 2		5,501		$ (76)		(156,066)
Treasury Stock, Value							$ (76)
Net loss	6,208							6,208
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	720			720
Adjustments to Additional Paid in Capital, Warrant Issued	9,422			9,422
Dividends, Preferred Stock, Stock	(918)			(918)
Shares, Issued		22,266				(14)
Stockholders' Equity Attributable to Parent	(135,207)	$ 2		14,725		$ (76)		(149,858)
Net loss	12,609							12,609
Earnout Shares removed from outstanding shares			(1,805)
Earnout shares monetary value removed	0	$ 0
Adjustments to Additional Paid in Capital, Share-based Compensation, Requisite Service Period Recognition	1,052			1,052
Adjustments to Additional Paid in Capital, Warrant Issued	3,000			3,000
Dividends, Preferred Stock, Stock	(759)			(759)
Shares, Issued		20,461				(14)
Stockholders' Equity Attributable to Parent	$ (119,305)	$ 2		$ 18,018		$ (76)		$ (137,249)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018
Cash flows from operating activities:
Net loss	$ (4,072)	$ (6,741)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
Depreciation and amortization	36,373	6,591
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Asset	(23,082)	0
Amortization of Other Deferred Charges	3,765	357
Share-based compensation expense	2,812	500
(Gain) loss on sale of equipment	743	28
Deferred compensation	1,494	313
Accrued dividends on Series B Preferred Stock	4,135	0
Deferred income taxes	(3,073)	(577)
Change in operating assets and liabilities:
Accounts receivable	(19,108)	(72,895)
Costs and estimated earnings in excess of billings on uncompleted contracts	(62,419)	(46,030)
Prepaid expenses and other assets	(5,938)	(1,489)
Accounts payable and accrued liabilities	3,317	131,682
Billings in excess of costs and estimated earnings on uncompleted contracts	9,580	19,896
Net cash provided by (used in) operating activities	(55,473)	31,635
Cash flow from investing activities:
Company-owned life insurance	(81)	(156)
Purchases of property, plant and equipment	(5,599)	(2,445)
Proceeds from sale of property, plant and equipment	7,266	40
Business Combination, Consideration Transferred	0	(106,579)
Net cash provided by (used in) investing activities	1,586	(109,140)
Cash flows from financing activities:
Proceeds from long-term debt	50,400	381,272
Repayments of Long-term Lines of Credit	(121,215)	(139,501)
Repayments of Lines of Credit	0	38,447
Early Repayment of Senior Debt	0	(51,762)
Debt financing fees	(14,738)	(12,675)
Payments on capital lease obligations	(15,953)	(4,284)
Sale Leaseback Transaction, Net Proceeds, Financing Activities	24,343	0
Payments of Dividends	0	548
Proceeds from Convertible Debt	100,000	0
Proceeds from Issuance of Shares under Incentive and Share-based Compensation Plans, Including Stock Options	159	0
Merger recapitalization transaction	2,754	(25,816)
Net cash provided by (used in) financing activities	25,750	108,239
Net change in cash and cash equivalents	(28,137)	30,734
Cash and cash equivalents, beginning of the period	71,311	4,877
Cash and cash equivalents, end of the period	43,174	35,611
Supplemental disclosure of cash and non-cash transactions:
Interest Paid, Excluding Capitalized Interest, Operating Activities	28,240	3,622
Cash paid for income taxes	250	649
Fair Value Of Assets Liabilities Acquired Through Capital Lease Obligations	1,992	12,133
Merger-related contingent consideration	0	69,373
Issuance of common shares	0	90,282
Issuance of preferred shares	0	34,965
Dividends, Preferred Stock	$ 2,202	$ 524

Business, Basis of Presentation

Business, Basis of Presentation and Significant Accounting Policies (Notes)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Organization, Consolidation and Presentation of Financial Statements Disclosure and Significant Accounting Policies [Text Block]	Business, Basis of Presentation and Significant Accounting Policies 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”). The Company specializes in providing complete engineering, procurement and construction (“EPC”) services throughout the United States (“U.S.”) for the renewable energy, traditional power and civil infrastructure industries. These services include the design, site development, construction, installation and restoration of infrastructure. Although the Company has historically focused on the wind industry, its recent acquisitions have expanded its construction capabilities and geographic footprint in the areas of renewables, environmental remediation, industrial maintenance, specialty paving and heavy civil and rail infrastructure construction, creating a diverse national platform of specialty construction capabilities. Principles of Consolidation The accompanying condensed unaudited 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. The condensed unaudited consolidated financial statements include the accounts of IEA and its wholly-owned direct and indirect domestic and foreign subsidiaries and 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 nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . These financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2018 and notes thereto included in the Company’s 2018 Annual Report on Form 10-K. Reportable Segments We segregate our business into two reportable segments: the Renewables (“Renewables”) segment and the Heavy Civil and Industrial (“Specialty Civil”) segment. See Note 13. Segments for a description of the reportable segments and their operations. Basis of Accounting and Use of Estimates The accompanying 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 project revenue and profit or loss (which the Company defines as project revenue less project costs of revenue), in particular, on construction contracts accounted for under the percentage-of completion method, for which the recorded amounts require estimates of costs to complete projects, ultimate project profit and the amount of probable contract price adjustments as inputs; allowances for doubtful accounts; accrued self-insurance reserves; other reserves and accruals; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that such 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. “Emerging Growth Company” Reporting Requirements: The Company qualifies as an “emerging growth company,” as defined in the Jumpstart Our Business Startups Act (the “JOBS Act”). For as long as a company is deemed to be an “emerging growth company,” it may take advantage of specified reduced reporting and other regulatory requirements that are generally unavailable to other public companies. Among other things, we are not required to provide an auditor attestation report on the assessment of the internal control over financial reporting under Section 404(b) of the Sarbanes-Oxley Act of 2002. Section 107 of the JOBS Act also provides that an “emerging growth company” can delay the adoption of certain accounting standards until those standards would otherwise apply to private companies. We have elected to take advantage of this extended transition period. Our financial statements may therefore not be comparable to those of companies that comply with such new or revised accounting standards. We would cease to be an “emerging growth company” upon the earliest of: • the last day of the fiscal year following July 6, 2021, the five-year anniversary of the completion of our IPO; • the last day of the fiscal year in which our total annual gross revenues exceed $1.07 billion; • the date on which we have, during the previous three-year period, issued more than $1 billion in non-convertible debt securities; or • the date on which we become a “large accelerated filer,” as defined in Rule 12b-2 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), which would occur if the market value of our common stock held by nonaffiliates exceeds $700 million as of the last day of our most recently completed second fiscal quarter. We continue to monitor our status as an “emerging growth company” and are currently preparing for, and expect to be ready to comply with, the additional reporting and regulatory requirements that will be applicable to us when we cease to qualify as an “emerging growth company.” Revenue Recognition Revenue under construction contracts is accounted for under the percentage-of-completion method of accounting. Under the percentage-of-completion method, the Company estimates profit as the difference between total estimated revenue and total estimated cost of a contract and recognizes that profit over the contract term based on costs incurred. Contract costs include all direct materials, labor and subcontracted costs and those indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs, depreciation and the operational costs of capital equipment. The Company also has unit-price contracts that were not significant as of September 30, 2019 . The estimation process for revenue recognized under the percentage-of-completion method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of contract revenue and costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected contract settlements are factors that influence estimates of total contract value and total costs to complete those contracts and, therefore, the Company’s profit recognition. Changes in these factors may result in revisions to revenue, costs and income, and their effects are recognized in the period in which the revisions are determined, which could materially affect the Company’s results of operations in the period in which such changes are recognized. Revenue derived from projects billed on a fixed-price basis totaled 98.5% and 99.8% of consolidated revenue from operations for the three months ended September 30, 2019 and 2018 , respectively, and totaled 94.1% and 97.4% for the nine months ended September 30, 2019 and 2018, respectively. Revenue and related costs for construction 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 also accounted for under the percentage of completion method totaled 1.5% and 0.2% of consolidated revenue from operations for the three months ended September 30, 2019 and 2018 , respectively, and totaled 5.9% and 2.6% for the nine months ended September 30, 2019 and 2018 , respectively. For an approved change order which can be reliably estimated as to price, the anticipated revenues and costs associated with the change order are added to the total contract value and total estimated costs of the project, respectively. When costs are incurred for a) an unapproved change order which is probable to be approved or b) an approved change order which cannot be reliably estimated as to price, the total anticipated costs of the change order are added to both the total contract value and total estimated costs for the project. Once a change order becomes approved and reliably estimable, any margin related to the change order is added to the total contract value of the project. The Company actively engages in substantive meetings with its customers to complete the final approval process and generally expects these processes to be completed within a year. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts. Provisions for losses on uncompleted contracts are made in the period in which such losses become evident. The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon engineering studies and legal opinions, past practices with the customer and specific discussions, correspondence and/or preliminary negotiations with the customer. Classification of Construction Contract-Related Assets and Liabilities Contract costs include all direct subcontract, material, and labor costs, and those indirect costs related to contract performance, such as indirect labor, supplies, tools, insurance, repairs, maintenance, communications, and use of Company-owned equipment. Contract revenues are earned and matched with related costs as incurred. Costs and estimated earnings in excess of billings on uncompleted contracts are presented as a current asset in the accompanying condensed consolidated balance sheets, and billings in excess of costs and estimated earnings on uncompleted contracts are presented as a current liability in the accompanying condensed consolidated balance sheets. The Company’s contracts vary in duration, with the duration of some larger contracts exceeding one year. Consistent with industry practices, the Company includes the amounts realizable and payable under contracts, which may extend beyond one year, in current assets and current liabilities. These contract balances are generally settled within one year. New Accounting Pronouncements The effective dates shown in the following pronouncements are based on the Company's current status as an “emerging growth company.” In May 2014, the Financial Accounting Standards Board ("FASB") issued guidance on the recognition of revenue from contracts with customers. The core principle of the guidance is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration which the company expects to receive in exchange for those goods or services. To achieve this core principle, the guidance provides a five-step analysis of transactions to determine when and how revenue is recognized. The guidance addresses several areas including transfer of control, contracts with multiple performance obligations, and costs to obtain and fulfill contracts. The guidance also requires additional disclosure about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. The standard will be effective for our fiscal year 2019 annual financial statements and for interim periods beginning in fiscal year 2020. The Company has substantially completed its assessment of the potential effects of these ASUs on its consolidated financial statements, business processes, systems and controls. The Company’s assessment included a detailed review of representative contracts at each of the Company’s segments and a comparison of its historical accounting policies and practices to the new standard. Based on the Company’s review of various types of revenue arrangements, the Company expects to recognize revenue and earnings over time utilizing the cost-to-cost measure of progress for its fixed price contracts and other service agreements, consistent with current practice. For these contracts, the cost-to-cost measure of progress best depicts the transfer of control of goods or services to the customer under the new standard. The Company has substantially completed its analysis of the information necessary to enable the preparation of the financial statements and related disclosures under the new standard. As part of this analysis, the Company evaluated its information technology capabilities and systems, and does not expect to incur significant information technology costs to modify systems currently in place. The Company will implement targeted changes to its internal reporting processes to facilitate gathering the data needed for reporting and disclosure under the new standard. The Company will also implement updates to its control processes and procedures, as necessary, based on changes resulting from the new standard. The Company does not expect any such updates to materially affect the Company’s internal controls over financial reporting. The Company anticipates adopting the standard using the modified retrospective transition approach. Under this approach, the new standard would apply to all new contracts initiated on or after January 1, 2019. For existing contracts that have remaining obligations as of January 1, 2019, any difference between the recognition criteria in these ASUs and the Company’s current revenue recognition practices would be recognized using a cumulative effect adjustment to the opening balance of retained earnings. Any potential effect of adoption of these ASUs has not yet been quantified; however, the Company anticipates the adoption will have an impact on both the amount and timing of revenue recognition related to unapproved change orders. The Company is training its impacted employees in business segments for the implementation of the new standard, and continues developing the disclosures required by the new standard. The Company is also reviewing certain contracts entered into by its business segments subsequent to its initial assessment that are expected to have performance obligations remaining as of January 1, 2019 for any cumulative effect adjustments that may be required upon adoption. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . Under ASU 2016-02, lessees will be required to recognize the following for all leases (with the exception of short-term leases) at the commencement date: 1) a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis, and 2) a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 required entities to adopt the new leases standard using a modified retrospective method and initially apply the related guidance at the beginning of the earliest period presented in the financial statements. During July 2018, the FASB issued ASU 2018-11, which allows for an additional and optional transition method under which an entity would record a cumulative-effect adjustment at the beginning of the period of adoption. See Note 10. Commitments and Contingencies for additional information about our leases. The Company will early adopt the standard and it will be effective for our fiscal year 2019 annual financial statements and for interim periods beginning in fiscal year 2020. The Company is in the process of implementing leasing software to assist in the integration of the future standard. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) , Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for recurring and non-recurring fair value measurements, such as the amount of and reason for transfers between Level 1 and Level 2 of the fair value hierarchy, and adds new disclosure requirements for Level 3 measurements. ASU 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for any eliminated or modified disclosures. Certain disclosures per ASU 2018-13 are required to be applied on a retrospective basis and others on a prospective basis. The Company is currently assessing the impact these changes will have on its disclosure requirements for fair value measurement. 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.

Acquisitions

Acquisitions	9 Months Ended
	Sep. 30, 2019
Business Combinations [Abstract]
Acquisitions	Acquisitions Acquisitions CCS On September 25, 2018, the Company completed its acquisition of Consolidated Construction Solutions I LLC (“CCS”) for $106.6 million in cash. The Company financed this acquisition through borrowing on its credit facility as discussed in Note 9. Debt. This acquisition is being accounted for as a business combination under the acquisition method of accounting. The wholly-owned subsidiaries of CCS, Saiia LLC (“Saiia”) and American Civil Constructors LLC (the “ACC Companies”), generally enter into long-term contracts with both government and non-government customers to provide EPC services for environmental, heavy civil and mining projects. William Charles On November 2, 2018, the Company acquired William Charles Construction Group, including its wholly-owned subsidiary Ragnar Benson (“William Charles”), for $77.7 million , consisting of $73.2 million in cash and $4.5 million of the Company's common stock ( 477,621 shares of common stock at $9.45 share price). The Company financed a portion of this acquisition through borrowing on its credit facility as discussed in Note 9. Debt. This acquisition is being accounted for as a business combination under the acquisition method of accounting. William Charles generally enters into contracts with a mix of government and non-government customers to provide EPC services for rail civil infrastructure, environmental and heavy civil projects. A portion of the non-governmental rail civil infrastructure contracts are longer than a year. The following table summarizes the amounts recognized for assets acquired and liabilities assumed as of the acquisition dates at fair value. The values for CCS were finalized as of June 30, 2019 and finalized for William Charles as of September 30, 2019. Identifiable assets acquired and liabilities assumed (in thousands) CCS William Charles Cash $ 6,413 $ 6,641 Accounts Receivable 58,041 69,740 Costs and estimated earnings in excess of billings on uncompleted contracts 9,512 16,095 Other current assets 1,813 7,999 Property, plant and equipment 59,952 47,899 Intangible assets: Customer relationships 19,500 7,000 Backlog 8,400 5,500 Tradename 8,900 4,500 Deferred income taxes (2,361 ) — Other non-current assets 134 75 Accounts payable and accrued liabilities (25,219 ) (60,962 ) Billings in excess of costs and estimated earnings on uncompleted contracts (14,194 ) (14,810 ) Debt, less current portion (52,257 ) (15,672 ) Capital lease obligations (1,124 ) — Other liabilities (704 ) (907 ) Total identifiable assets 76,806 73,098 Goodwill 29,773 4,581 Total purchase consideration $ 106,579 $ 77,679 * - There were no measurement period adjustments for the quarter ended September 30, 2019. Goodwill is calculated as the excess of the consideration transferred over the net assets recognized and represents the future economic benefits arising from other assets acquired that could not be individually identified and separately recognized. Specifically, the goodwill recorded as part of the acquisitions of CCS and William Charles is related to the expected, specific synergies and other benefits that the Company believes will result from combining the operations of CCS and William Charles with the operations of IEA. This goodwill is deductible for income tax purposes, with the exception of $2.9 million for CCS that is not deductible. Impact of Acquisitions The following table summarizes the results of operations included in the Company's condensed consolidated statement of operations for CCS and William Charles from their respective dates of acquisition. (in thousands) Three months ended September 30, 2019 Nine months ended September 30, 2019 CCS William Charles CCS William Charles Revenue 81,248 84,033 211,117 198,879 Net income (loss) 2,707 7,308 616 7,359 Three months ended September 30, 2018 Nine months ended September 30, 2018 CCS William Charles CCS William Charles Revenue 5,600 — 5,600 — Net income (loss) — — — — The following table provides the supplemental unaudited actual and pro forma total revenue and net income of the combined entity had the acquisition date of CCS and William Charles been the first day of our fiscal year 2018: Three months ended September 30, Nine months ended September 30, (in thousands) Actual 2019 Pro forma 2018 Actual 2019 Pro forma 2018 Revenue 422,022 446,557 940,793 948,543 Net income (loss) 12,609 6,016 (4,072 ) (15,448 ) Net income (loss) per common share: Basic earnings per share 0.37 0.25 (1.44 ) (0.77 ) Diluted earnings per share 0.24 0.24 (1.44 ) (0.77 ) The amounts in the supplemental unaudited pro forma 2018 results apply the Company's accounting policies and reflect certain adjustments to, among other things, (i) exclude the impact of transaction costs incurred in connection with the acquisitions, (ii) include additional depreciation and amortization that would have been charged assuming the same fair value adjustments to property, plant and equipment and acquired intangibles had been applied on January 1, 2018, and (iii) include additional interest expense that would have been incurred assuming the incremental borrowings the Company incurred to finance the acquisitions had been outstanding on January 1, 2018. Accordingly, these supplemental unaudited pro forma results have been prepared for comparative purposes only and are not intended to be indicative of the results of operations that would have occurred had the acquisitions actually occurred in the prior year period or indicative of the results of operations for any future period. These results do not include any potential operating efficiencies and cost savings.

Earnings per share

Earnings per share	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Earnings per share	Earnings Per Share The Company calculates earnings (loss) per share (“EPS”) in accordance with ASC 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. Subsequent to the issuance of the Company's condensed consolidated financial statements for the three and six months ended June 30, 2019, the Company identified a computational error related to the number of outstanding common shares included in its earnings (loss) per share calculations during 2018 and 2019. Management has concluded that the impact of this error on all historical periods is immaterial and therefore has not adjusted the earnings (loss) per share amounts for any periods prior to September 30, 2019. Rather, the adjustment to remove 1.8 million unvested shares has been made beginning with the three- and nine-months ended September 30, 2019. The number of outstanding shares of Common Stock for voting purposes remains at 22.3 million shares, as the aforementioned 1.8 million shares are entitled to vote those shares during the vesting period. Income (loss) available to common stockholders is computed by deducting the dividends accumulated for the period on cumulative preferred stock from net income. If there is a net loss, the amount of the loss is increased by those preferred dividends. The contingent consideration fair value adjustment is a mark-to-market adjustment based on the decline of approximately 80% in the Company's stock price from December 31, 2018 to June 30, 2019, coupled with the Company not anticipating reaching Adjusted EBITDA requirements outlined in the original agreement at September 30, 2019, see Note. 8 Fair Value of Financial Instruments . The Company is required to reverse the mark-to-market adjustment from the numerator as shown below. Diluted EPS assumes the dilutive effect of (i) contingently issuable earn-out shares, (ii) Series A cumulative convertible preferred stock, using the if-converted method, and (iii) the assumed exercise of in-the-money stock options and warrants 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 ($ in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Numerator: Net income (loss) 12,609 5,736 (4,072 ) (6,741 ) Less: Convertible Preferred Stock dividends (759 ) (524 ) (2,202 ) (1,072 ) Less: Contingent consideration fair value adjustment (see Note 8) (4,247 ) — (23,082 ) — Net income (loss) available to common stockholders 7,603 5,212 (29,356 ) (7,813 ) Denominator: Weighted average common shares outstanding - basic (1) 20,446,811 21,577,650 20,425,801 21,577,650 Series B Preferred - Warrants 2,845,840 — — — Convertible Series A Preferred Stock 11,486,534 3,522,438 — — Restricted stock units 640,247 — — — Weighted average shares for diluted computation 35,419,432 25,100,088 20,425,801 21,577,650 Anti-dilutive: (2)(3) Convertible Series A Preferred — — 8,968,856 2,832,765 Series B Preferred - Warrants at closing — — 1,325,779 — RSUs — — 542,421 — Basic EPS 0.37 0.24 (1.44 ) (0.36 ) Diluted EPS 0.24 0.23 (1.44 ) (0.36 ) (1) The contingent earn-out shares were not included at September 30, 2019 and were removed from September 30, 2018, respectively. See Note 8. Fair Value of Financial Instruments for discussion regarding the Company's contingently issuable earn-out shares. (2) Warrants to purchase 8,480,000 shares of common stock at $11.50 per share were outstanding at September 30, 2019 and 2018 but were not potentially dilutive as the warrants’ exercise price was greater than the average market price of the common stock during the period. 646,405 of vested and unvested Options and 817,817 of unvested RSUs were also not potentially dilutive as of September 30, 2019 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. (3) The 1.8 million unvested earnout shares were not included at September 30, 2019 due to the exercise price being greater than the average market price of the common stock during the period. Series A Preferred Stock As of September 30, 2019, we had 34,965 shares of Series A Preferred Stock with an initial stated value of $1,000 per share plus accumulated but unpaid dividends, for total consideration of $37.7 million . Dividends are paid on the Series A Preferred Stock 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 the following rates: • 6% per annum from the original issuance of the Series A Preferred Stock on March 26, 2018 (the “Closing Date”) until the date (the “ 18 Month Anniversary Date”) that is 18 months from the Closing Date; and • 10% per annum during the period from and after the 18 Month Anniversary Date; So long as any shares of Series B Preferred Stock of the Company, (the “Series B Preferred Stock”), which are currently either designated as Series B-1 Preferred Stock (“Series B-1 Preferred Stock”) or Series B-2 Preferred Stock (“Series B-2 Preferred Stock”), and (referred to collectively as “Series B Preferred Stock”), are 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. 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 the following rates: • 8% per annum during the period from May 20, 2019 through the 18 Month Anniversary Date; and • 12% per annum during the period from and after the 18 Month Anniversary Date. As of September 30, 2019 , the Company has accrued a cumulative of $2.7 million in dividends to holders of Series A Preferred Stock as a reduction to additional paid-in capital. Series B Preferred Stock As of September 30, 2019, we had 100,000 shares of Series B Preferred Stock outstanding, with each share having an initial stated value of $1,000 plus accumulated but unpaid dividends. Our common stock and Series A Preferred Stock are junior to the Series B Preferred Stock. Dividends are paid on the Series B Preferred Stock when declared by our Board. To the extent not prohibited by applicable law, dividends are required to be declared and paid in cash quarterly in arrears on each March 31, June 30, September 30 and December 31 at the following rates: • On Series B-1 Preferred Stock with respect to any dividend period for which the Total Net Leverage Ratio (as defined in the Third A&R Credit Agreement (as defined in see Note. 9 Debt ) is greater than 1.50 :1.00, 15% per annum (or 13.5% per annum if a deleveraging event (as defined below) has occurred prior to the date dividends are paid with respect to such dividend period) and (ii) with respect to any dividend period for which the Total Net Leverage Ratio is less than or equal to 1.50 :1.00, 13.5% per annum. • On Series B-2 Preferred Stock with respect to any dividend period for which the Total Net Leverage Ratio is greater than 1.50 :1.00, 15% per annum (or 13.5% per annum if a deleveraging event has occurred prior to the date dividends are paid with respect to such dividend period) and (ii) with respect to any dividend period for which the Total Net Leverage Ratio is less than or equal to 1.50 :1.00, 12% per annum. If not paid in cash, dividends will accrue on the stated value and will increase the stated value on Series B Preferred Stock and is effective as of the applicable dividend date without any further action by the Board at a rate of 18% per annum; provided that, during the period from the occurrence of a deleveraging event until the date that is two years from such deleveraging event, such dividend rate shall instead be 15% per annum. A deleveraging event means certain equity financings or issuances of stock where the proceeds of such equity financings are used exclusively to permanently reduce senior secured indebtedness by at least $50.0 million , or the Total Net Leverage Ratio as of the last day of any fiscal quarter is less than or equal to 1.50 :1.00. The Company has accrued a cumulative of $4.1 million in accrued dividends to holders of Series B Preferred Stock, which is recorded as interest expense in the Company's condensed consolidated statements of operations for the quarter ended September 30, 2019. See Note 8. Fair Value of Financial Instruments for discussion regarding the Company's valuation of Series B Preferred Stock. 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 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 September 30, 2019 and 2018, we recognized $1.1 million and $0.5 million in compensation expense, respectively, and $2.8 million and $0.5 million for the nine months ended September 30, 2019 and 2018, respectively.

Accounts receivable, net of all

Accounts receivable, net of allowance	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Accounts receivable, net of allowance	Accounts Receivable, Net The following table provides details of accounts receivable, net of allowance as of the dates indicated (in thousands): September 30, 2019 December 31, 2018 Contract receivables $ 168,413 $ 161,408 Contract retainage 76,103 64,000 Accounts receivable, gross 244,516 225,408 Less: allowance for doubtful accounts (51 ) (42 ) Accounts receivable, net $ 244,465 $ 225,366 Included in costs in excess of billings as of September 30, 2019 are unapproved change orders of approximately $21.0 million for which the Company is pursuing settlement through dispute resolution. Activity in the allowance for doubtful accounts for the periods indicated is as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Allowance for doubtful accounts at beginning of period $ 102 $ 216 $ 42 $ 216 Plus: provision for allowances 30 — 90 — Less: write-offs, net of recoveries (81 ) — (81 ) — Allowance for doubtful accounts at period end $ 51 $ 216 $ 51 $ 216

Contracts in progress

Contracts in progress	9 Months Ended
	Sep. 30, 2019
Contractors [Abstract]
Contracts in progress	Contracts in Progress Contracts in progress were as follows as of the dates indicated (in thousands): September 30, 2019 December 31, 2018 Costs on contracts in progress $ 1,189,496 $ 935,820 Estimated earnings on contracts in progress 111,451 76,883 Revenue on contracts in progress 1,300,947 1,012,703 Less: billings on contracts in progress (1,263,221 ) (1,027,816 ) Net underbillings (overbillings) $ 37,726 $ (15,113 ) The above amounts have been included in the accompanying condensed consolidated balance sheets under the following captions (in thousands): September 30, 2019 December 31, 2018 Costs and estimated earnings in excess of billings on uncompleted contracts $ 109,540 $ 47,121 Billings in excess of costs and earnings on uncompleted contracts (71,814 ) (62,234 ) Net underbillings (overbillings) $ 37,726 $ (15,113 ) Provision for loss of $0.1 million and $1.4 million as of September 30, 2019 and December 31, 2018, respectively, is included in billings in excess of costs and earnings on uncompleted contracts. The Company recognizes a contract asset within costs and estimated earnings in excess of billings on uncompleted contracts in the condensed consolidated balance sheet for revenue earned related to unapproved change orders that are probable of recovery. For the quarter ended September 30, 2019 and the year ended December 31, 2018, the Company had unapproved change orders of $69.9 million and $45.0 million , respectively.

Property, plant and equipment,

Property, plant and equipment, net	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Property, plant and equipment, net	Property, Plant and Equipment, Net Property, plant and equipment, net consisted of the following (in thousands): September 30, 2019 December 31, 2018 Buildings and leasehold improvements $ 2,812 $ 4,614 Land 17,600 19,394 Construction equipment 178,239 175,298 Office equipment, furniture and fixtures 3,449 2,994 Vehicles 5,985 4,991 208,085 207,291 Accumulated depreciation (56,301 ) (31,113 ) Property, plant and equipment, net $ 151,784 $ 176,178 Depreciation expense of property, plant and equipment was $9,219 and $2,471 for the period ended September 30, 2019 and 2018 , respectively, and was $26,125 and $6,388 for the nine months ended September 30, 2019 and 2018 , respectively.

Goodwill and Intangible Assets,

Goodwill and Intangible Assets, net (Notes)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets, Net [Abstract]
Goodwill and Intangible Assets Disclosure [Text Block]	Goodwill and Intangible Assets, Net The following table provides the changes in the carrying amount of goodwill for 2019 and 2018: (in thousands) Goodwill January 1, 2018 (Renewables Segment) $ 3,020 Acquisitions (Specialty Civil Segment) 37,237 December 31, 2018 $ 40,257 Acquisition adjustments (Specialty Civil Segment) (2,884 ) September 30, 2019 $ 37,373 Intangible assets, net consisted of the following as of the dates indicated: September 30, 2019 December 31, 2018 ($ 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 $ (3,749 ) $ 22,751 6 years $ 27,000 $ (814 ) $ 26,186 7 years Trade name 13,400 (2,635 ) 10,765 4 years 13,400 (575 ) 12,825 5 years Backlog 13,900 (6,791 ) 7,109 1 year 13,400 (1,537 ) 11,863 2 years $ 53,800 $ (13,175 ) $ 40,625 $ 53,800 $ (2,926 ) $ 50,874 Amortization expense associated with intangible assets for the three months ended September 30, 2019 and 2018 , totaled $3.4 million and $0.1 million , respectively, and $10.3 million and $0.2 million for the nine months ended September 30, 2019 and 2018 , respectively. The following table provides the annual intangible amortization expense currently expected to be recognized for the years 2019 through 2023: (in thousands) Remainder of 2019 2020 2021 2022 2023 Amortization expense $ 3,354 $ 11,837 $ 6,466 $ 6,466 $ 5,841

Fair value of financial instrum

Fair value of financial instruments	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Fair value of financial instruments	Fair Value of Financial Instruments The Company applies ASC 820, Fair Value Measurement, which establishes a framework for measuring fair value and clarifies the definition of fair value within that framework. 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 to be 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 — Assets and liabilities with unadjusted, quoted prices listed on active market exchanges. Inputs to the fair value measurement are observable inputs, such as quoted prices in active markets for identical assets or liabilities. 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 assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements at Reporting Date Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities as of December 31, 2018 Contingent consideration 23,082 — — 23,082 Fair Value Measurements at Reporting Date Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities as of September 30, 2019 Contingent consideration — — — — Series B-1 Preferred Stock - Series A Conversion Warrants 4,200 — — 4,200 Series B-1 Preferred Stock - Additional 6% Warrants 400 — — 400 The following is a reconciliation of the beginning and ending balances for the periods indicated of recurring fair value measurements using Level 3 inputs (in thousands): Contingent Consideration Series B Preferred - Series A Conversion Warrants Series B Preferred - Additional 6% Warrants Beginning Balance, December 31, 2018 23,082 $ — $ — Preferred Series B-1 Stock - Additional Warrants — 4,200 400 Fair value adjustment (23,082 ) — — Ending Balance, September 30, 2019 — 4,200 400 Contingent Consideration Pursuant to the original merger agreement with M III Acquisition Corp., the Company shall issue up to an additional 9,000,000 shares of common stock, which shall be fully earned if the final 2019 adjusted EBITDA targets are achieved. As of September 30, 2019, the Company recorded an adjustment of $23.1 million to the liability primarily based on a significant decrease in the Company's stock price for the first six months of 2019 of approximately 80.0% (from $8.61 at December 31, 2018 to $2.04 at June 30, 2019), coupled with the Company not anticipating reaching EBITDA requirements outlined in the original agreement as of September 30, 2019. The following table sets forth information regarding the Company's assets measured at fair value on a non-recurring basis (in thousands): Fair Value Measurements Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Series B-1 and Series B-2 Preferred Stock 81,300 — — 81,300 Equity: Series B-1 Preferred Stock - Warrants at closing 14,100 — — 14,100 On May 20, 2019, the Company entered into the Amended and Restated Equity Commitment Agreement (the “First Equity Commitment Agreement”), by and among the Company and the commitment parties thereto. Pursuant to the First Equity Commitment Agreement, the Company issued and sold on May 20, 2019, 50,000 shares of Series B-1 Preferred Stock, with each share having an initial stated value of $1,000 plus accumulated but unpaid dividends for gross cash proceeds of $50.0 million . The First Equity Commitment Agreement also required the Company to provide warrants for common stock at closing that equaled 10% of the fully diluted issued and outstanding common stock as of such date (the “Warrants at closing”), and in the future could be required to provide additional warrants in the event of conversion of the Series A Preferred Stock (“Series A Conversion Warrants”) and warrants for up to 6% of the fully diluted issued and outstanding common stock if the Company fails to meet certain Adjusted EBITDA thresholds on a trailing twelve-month basis on the last calendar day of May 2020 through April 2021 (the “Additional 6% Warrants”). On August 13, 2019, the Company entered into the Second Equity Commitment Agreement (the “Second Equity Commitment Agreement”). Pursuant to the Second Equity Commitment Agreement, the Company issued and sold on August 30, 2019, 50,000 shares of Series B-2 Preferred Stock and 900,000 warrants to purchase common stock (“Warrants”) for an aggregate purchase price of $50.0 million . The information below describes the balance sheet classification and the recurring/nonrecurring fair value measurement: Series B-1 and Series B-2 Preferred Stock (non-recurring) - The Series B-1 and Series B-2 Preferred Stock were recorded at relative fair value as debt which was estimated using a discounted cashflow model based on certain significant unobservable inputs, such as accumulated dividend rates, and projected Adjusted EBITDA for the life of the Series B Preferred Stock. The fair value of the liability for each of the transactions closed on May 20, 2019 and August 30, 2019, was a combined $81.3 million and recorded on the balance sheet as debt. Series B-1 and Series B-2 Preferred Stock - Warrants at closing (non-recurring) - The Warrants at closing, with an exercise price of $0.0001 , represented (on an if-converted to common stock basis) 10% of the issued and outstanding common stock of the Company based on the Company’s fully diluted share count on May 20, 2019 (including the number of shares of common stock that may be issued pursuant to all restricted stock awards, restricted stock units, stock options and any other securities or rights (directly or indirectly) convertible into, exchangeable for or to subscribe for common stock that are outstanding on May 20, 2019 (excluding any shares of common stock issuable (a) pursuant to the merger agreement for our business combination, (b) upon conversion of shares of Series A Preferred Stock, (c) upon the exercise of any warrant with an exercise price of $11.50 or higher or (d) upon 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). The 2,545,934 if-converted shares of common stock at closing were valued at the closing stock price of $4.21 on May 20, 2019 and recorded in additional paid in capital. On August 30, 2019, 900,000 if-converted shares of common stock were issued and were valued at the closing stock price of $3.75 and recorded in additional paid in capital. Series B-1 Preferred Stock - Series A Conversion Warrants (recurring) - The certificate of designation for the Series A Preferred Stock was amended in connection with the Company entering into the First Equity Commitment Agreement. The conversion rights were amended to allow the holders of Series A Preferred Stock to convert all or any portion of Series A Preferred Stock outstanding at any point in time. If converted, the holders of the Series B Preferred Stock would be entitled to additional warrants, with an exercise price of $0.0001 . These warrants were fair valued using the closing stock price of $4.21 on May 20, 2019, at an estimated if-converted share count and recorded as a liability. Series B-1 Preferred Stock - Additional 6% Warrants (recurring) - The Additional 6% Warrants are issuable if the Company fails to meet certain Adjusted EBITDA thresholds on a trailing twelve-month basis from May 31, 2020 through April 30, 2021. The Company recorded the Additional 6% Warrants at fair value, which was estimated 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 for 2019. The Additional 6% Warrants were recorded as a liability. 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, further discussed in Note 9. Debt , approximates fair value due to their floating interest rates.

Debt

Debt	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Debt	Debt Debt consists of the following obligations as of: September 30, 2019 December 31, 2018 Term loan 277,688 300,000 Line of credit — 46,500 Commercial equipment notes 3,820 5,341 Total principal due for long-term debt 281,508 351,841 Unamortized debt discount and issuance costs (23,783 ) (23,534 ) Less: Current portion of long-term debt (31,119 ) (32,580 ) Long-term debt, less current portion 226,606 295,727 Debt - Series B Preferred Stock (1) 104,135 — Unamortized debt discount and issuance costs (27,369 ) — Long-term Series B Preferred Stock 76,766 — (1) The Company has accrued a cumulative of $4.1 million in accrued dividends to holders of Series B Preferred Stock, which is recorded as interest expense in the Company's condensed consolidated statements of operations for the quarter ended September 30, 2019. Third Amended and Restated Credit Agreement On May 20, 2019, the Third Amended and Restated Credit and Guarantee Agreement (the “Third A&R Credit Agreement”) became effective. Term loan borrowings mature on September 25, 2024 and are subject to quarterly amortization of principal, commencing on March 31, 2019, in an amount equal to 2.50% of the aggregate principal amount of such loans. Beginning with 2020, an additional annual payment is required equal to 75% of Excess Cash Flow (as defined in the Third A&R Credit Agreement) for the preceding fiscal year if such Excess Cash Flow is greater than $2.5 million , with the percentage of Excess Cash Flow subject to reduction based upon the Company’s consolidated leverage ratio. Borrowings under the term loan are required to be repaid on the last business day of each March, June, September and December, continuing with the first fiscal quarter following the effective date of the Third A&R Credit Agreement, in an amount equal to 2.5% of the initial balance of the initial term loan and will not be able to be reborrowed. Borrowings under the revolving line of credit mature on September 25, 2023. Interest on the consenting lender term loan tranche accrues at a per annum rate of, at the Company's option, (x) LIBOR plus a margin of 8.25% or (y) an alternate base rate plus a margin of 7.25% ; provided, however, that upon achieving a First Lien Net Leverage Ratio (as defined below) of no greater than 2.67 :1.00, the margin shall permanently step down to (y) for LIBOR loans, 6.75% and (x) for alternative base rate loans, 5.75% . Interest on the non-consenting lender term loan tranche will stay at a per annum rate of, at the Company’s option, (x) LIBOR plus a margin of 6.25% or (y) an alternate base rate plus a margin of 5.25% . Interest on initial revolving facility borrowings and swing line loans accrues at a rate of, at the Company's option, (x) LIBOR plus a margin of 4.25% or (y) the applicable base rate plus a margin of 3.25% . The weighted average interest rate under the Third A&R Credit Agreement as of September 30, 2019 and December 31, 2018 , was 10.42% and 8.82% , respectively. The terms of the Third A&R Credit Agreement include customary affirmative and negative covenants and provide for customary events of default, which include, among others, nonpayment of principal or interest and failure to timely deliver financial statements. Under the Third A&R Credit Agreement, the financial covenant to which the Credit Parties as defined therein are subject provides that the First Lien Net Leverage Ratio (as defined therein) may not exceed (i) prior to the fiscal quarter ending December 31, 2019, 4.75 :1.0, (ii) from and prior to the fiscal quarter ending December 31, 2020, 3.50 :1.0, (iii) from and prior to the fiscal quarter ending December 31, 2021, 2.75 :1.0, and (iv) from and after March 31, 2022, 2.25 :1.0. Under the Third A&R Credit Agreement, the Company is not to obtain an equity infusion to cure for any covenant violations for fiscal quarter ending in 2019, excluding the Series B Preferred Stock. Thereafter, the Company will have access to a customary equity cure. 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. Letters of Credit and Surety Bonds In the ordinary course of business, the Company is required to post letters of credit and surety bonds to customers in support of performance under certain contracts. Such letters of credit are generally issued by a bank or similar financial institution. The letter of credit or surety bond commits the issuer to pay specified amounts to the holder of the letter of credit or surety bond under certain conditions. If the letter of credit or surety bond issuer were required to pay any amount to a holder, the Company would be required to reimburse the issuer, which, depending upon the circumstances, could result in a charge to earnings. As of September 30, 2019 , and December 31, 2018 , the Company was contingently liable under letters of credit issued under its Third A&R Credit Agreement or its old credit facility, respectively, in the amount of $21.0 million and $3.0 million , respectively, related to projects. In addition, as of September 30, 2019 and December 31, 2018 , the Company had outstanding surety bonds on projects of $2,017.6 million and $1,682.0 million , respectively. Contractual Maturities Contractual maturities of the Company's debt and capital lease (see Note 10. Commitments and Contingencies) obligations as of September 30, 2019 (in thousands): Remainder of 2019 $ 13,965 2020 55,988 2021 51,826 2022 47,276 2023 32,905 Thereafter 257,591 Total contractual obligations $ 459,551

Commitments and contingencies

Commitments and contingencies	9 Months Ended
	Sep. 30, 2019
Commitments and Contingencies Disclosure [Abstract]
Commitments and contingencies	Commitments and Contingencies Capital Leases The Company has obligations, exclusive of associated interest, under various capital leases for equipment totaling $73.9 million and $63.5 million at September 30, 2019 and December 31, 2018 , respectively. Gross property under this capitalized lease agreement at September 30, 2019 and December 31, 2018 , totaled $119.6 million and $76.9 million , less accumulated depreciation of $ 29.3 million and $10.1 million , respectively, for net balances of $ 90.3 million and $66.8 million , respectively. Depreciation of assets held under the capital leases is included in the cost of revenue in the condensed consolidated statements of operations. Operating Leases In the ordinary course of business, the Company enters into non-cancelable operating leases for certain of its facility, vehicle and equipment needs, including related party leases. See Note 14. Related Party Transactions . Rent and related expense for operating leases that have non-cancelable terms totaled approximately $4.3 million and $0.5 million for the three months ended September 30, 2019 and 2018 , respectively and $9.5 million and $1.5 million for the nine months ended September 30, 2019 and 2018, respectively. The Company has long-term power-by-the-hour equipment rental agreements,included in non-canceable operating lease expense above, 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 was $3.2 million for the nine months ended September 30, 2019. Sale-leaseback Transaction On March 13, 2019, the Company completed a sale-leaseback transaction related to certain assets that were acquired as part of our recent acquisitions of $25.0 million . The payments related to this transaction are over a four year term and have been included as part of the Contractual Maturities table, See Note 9. Debt .

Concentrations

Concentrations	9 Months Ended
	Sep. 30, 2019
Risks and Uncertainties [Abstract]
Concentrations	Concentrations The Company had the following approximate revenue and accounts receivable concentrations, net of allowances, for the periods ended: Revenue % Accounts Receivable % Three Months Ended Nine Months Ended September 30, September 30, September 30, 2019 December 31, 2018 2019 2018 2019 2018 Company A * 24.1 % * 22.6 % * 20.0 % Company B * 16.7 % * 12.1 % * * Company C * * 11.7 % * * 19.0 % Company D * 11.7 % * * * * * Amount was not above 10% threshold

Income taxes

Income taxes	9 Months Ended
	Sep. 30, 2019
Income Tax Disclosure [Abstract]
Income taxes	Income Taxes The Company’s statutory federal tax rate was 21.00% for the periods ended September 30, 2019 and 2018 , 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 September 30, 2019 and 2018 were (4.6)% and 13.2% , respectively. The effective tax rates for the nine months ended September 30, 2019 and 2018 were 43.0% and 15.8% , respectively. The difference between the Company’s effective tax rate and the federal statutory rate primarily results from permanent differences related to the revaluation of the contingent liability fair value adjustment and interest accrued for the Series B Preferred Stock, which is not deductible for federal and state income taxes. There were no changes in uncertain tax positions during the periods ended September 30, 2019 and 2018 .

Segments (Notes)

Segments (Notes)	9 Months Ended
	Sep. 30, 2019
Segments [Abstract]
Segment Reporting Disclosure [Text Block]	Segments The Company operated as one reportable segment for 2018 and evaluated the business as a renewable construction company. In late 2018, the Company completed two significant acquisitions that construct projects outside of the renewable market. As of September 30, 2019, we operate our business as two reportable segments: the Renewables segment and the Specialty Civil segment. The 2018 segment presentation has been recast to be consistent to the 2019 segmentation. Each of our reportable segments is comprised of similar business units that specialize in services unique to the respective markets that each segment serves. 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: The Renewables segment operates throughout the United States and specializes in a range of services that include full EPC project delivery, design, site development, construction, installation and restoration of infrastructure services for the wind and solar industries. The Specialty Civil segment operates throughout the United States and specializes in a range of services that include: • Heavy civil construction services such as high-altitude road and bridge construction, specialty paving, industrial maintenance and other local, state and government projects. • Environmental remediation services such as site development, environmental site closure and outsourced contract mining and coal ash management services. • Rail Infrastructure services such as planning, creation and maintenance of infrastructure projects for major railway and intermodal facilities construction. Segment Revenue Revenue by segment was as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2019 2018 2019 2018 Segment Revenue % of Total Revenue Revenue % of Total Revenue Revenue % of Total Revenue Revenue % of Total Revenue Renewables $ 242,654 57.5 % $ 262,477 94.0 % $ 496,863 52.8 % $ 480,362 95.4 % Specialty Civil 179,368 42.5 % 16,802 6.0 % 443,930 47.2 % 23,125 4.6 % Total revenue $ 422,022 100.0 % $ 279,279 100.0 % $ 940,793 100.0 % $ 503,487 100.0 % Segment Gross Profit Gross profit by segment was as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2019 2018 2019 2018 Segment Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Renewables $ 27,469 11.3 % $ 24,822 9.5 % $ 45,806 9.2 % $ 37,578 7.8 % Specialty Civil 25,401 14.2 % 2,186 13.0 % 45,259 10.2 % 3,144 13.6 % Total gross profit $ 52,870 12.5 % $ 27,008 9.7 % $ 91,065 9.7 % $ 40,722 8.1 %

Related party transactions

Related party transactions	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Related party transactions	Related Party Transactions Clinton Lease Agreement On October 20, 2017, the Company enacted a plan to restructure the ownership of a building and land which resulted in the transfer of ownership of such building and land from its consolidated subsidiary, White Construction, LLC, to Clinton RE Holdings, LLC (Cayman) (“Cayman Holdings”), a directly owned subsidiary of the Infrastructure and Energy Alternatives, LLC. The lease has been classified as an operating lease with monthly payments through 2038. The Company's rent expense related to the lease during the three months ended September 30, 2019 and 2018, was $178 and $153 , respectively, and for the nine months ended September 30, 2019 and 2018, was $534 and $459 , respectively. On October 30, 2019, Cayman Holdings sold the building to a third party that assumed the future payments and terms of the existing lease. The Company will continue to have rent expense related to the lease but it will no longer be with a related party. Related Party Shareholders Type of Equity Holder Ownership Percentage Series A Preferred Infrastructure and Energy Alternatives, LLC 100 % Series B-1 Preferred Stock, Series A Conversion Warrants, Additional 6% Warrants, Warrants at closing Ares 60 % Oaktree Power Opportunities Fund III Delaware, L.P. 40 % Contingent Consideration Infrastructure and Energy Alternatives, LLC 100 % Series B-2 Preferred Stock Ares 100 %

Subsequent Event (Notes)

Subsequent Event (Notes)	9 Months Ended
	Sep. 30, 2019
Subsequent Event [Abstract]
Subsequent Events [Text Block]	Subsequent Event Third Equity Commitment Agreement On October 29, 2019, the Company entered into the Third Equity Commitment Agreement (the “Third Equity Commitment Agreement”) among the Company, funds managed by Ares Management Corporation (“Ares”) and funds managed by Oaktree Capital Management (“Oaktree”). Pursuant to the Third Equity Commitment Agreement, the Company agreed to issue and sell 80,000 shares of newly designated Series B-3 Preferred Stock (the “Series B-3 Preferred Stock”) and 3,568,750 Warrants for an aggregate purchase price of $80.0 million (the “Initial Closing”). Consummation of the Initial Closing is subject to a number of conditions; however, funding is expected to occur within 12 business days from October 29th. After the Initial Closing, Ares and Oaktree, pursuant to the Third Equity Commitment Agreement are each required, subject to certain conditions, to purchase up to an additional 15,000 shares (collectively 30,000 shares) of Series B-3 Preferred Stock and 515,625 Warrants (collectively 1,031,250 Warrants), resulting in additional proceeds to the Company in an amount of up to $30.0 million , if, by certain agreed upon dates, the Company has not repaid at least an additional $30.0 million under its term loan using excess cash and proceeds from the Rights Offering. Rights Offering Agreement On October 29, 2019, the Company entered into the Rights Offering Agreement (the “Rights Agreement”). Pursuant to the Rights Agreement, assuming all applicable conditions are satisfied, the Company has agreed to conduct a rights offering and to distribute a transferrable right, but not the obligation, to purchase Series B-3 Preferred Stock and warrants to purchase common stock to the holders of the Company’s outstanding common stock other than parties to the Third Equity Commitment Agreement and each of their director designees, the officers of the Company, and any related party of the foregoing (the “Rights Offering”). The Rights Offering will be subject to a maximum participation of 15,000 shares of Series B-3 Preferred Stock being issued, plus warrants at the rate of 5.5 per $160 of Series B-3 Preferred Stock purchased, an individual investment minimum of $50,000 and an individual investment maximum of the greater of the holder's pro rata share of the common stock eligible to participate and $2.25 million . Preferred Stock Exchange Agreement On October 29, 2019, the Company entered into the Preferred Stock Exchange Agreement (the “Exchange Agreement”). Pursuant to the Exchange Agreement, the holder of our Series A Preferred Stock has agreed to exchange 50% of its total Series A Preferred Stock outstanding into shares of Series B-3 Preferred Stock and Warrants at the Initial Closing. The number of shares of Series B-3 Preferred Stock to be issued in the exchange will be calculated by dividing the stated value (including unpaid accumulated and compounded dividends) of each share of Series A Preferred Stock to be exchanged by a price per share of Series B-3 Preferred Stock of $1,000 . The number of warrants to be issued will be at a rate of 5.5 warrants per $160 of stated value of the Series A Preferred Stock exchanged.

Business, Basis of Presentati_2

Business, Basis of Presentation and Significant Accounting Policies (Policies)	9 Months Ended
	Sep. 30, 2019
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Basis of Accounting, Policy [Policy Text Block]	The accompanying consolidated financial statements have been prepared in accordance with GAAP.
Consolidation, Policy [Policy Text Block]	Principles of Consolidation The accompanying condensed unaudited 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. The condensed unaudited consolidated financial statements include the accounts of IEA and its wholly-owned direct and indirect domestic and foreign subsidiaries and 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 nine months ended September 30, 2019 are not necessarily indicative of the results that may be expected for the year ending December 31, 2019 . These financial statements should be read in conjunction with the Company’s audited consolidated financial statements for the year ended December 31, 2018 and notes thereto included in the Company’s 2018 Annual Report on Form 10-K.
Segment Reporting, Policy [Policy Text Block]	Reportable Segments We segregate our business into two reportable segments: the Renewables (“Renewables”) segment and the Heavy Civil and Industrial (“Specialty Civil”) segment. See Note 13. Segments for a description of the reportable segments and their operations.
Use of Estimates, Policy [Policy Text Block]	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 project revenue and profit or loss (which the Company defines as project revenue less project costs of revenue), in particular, on construction contracts accounted for under the percentage-of completion method, for which the recorded amounts require estimates of costs to complete projects, ultimate project profit and the amount of probable contract price adjustments as inputs; allowances for doubtful accounts; accrued self-insurance reserves; other reserves and accruals; accounting for income taxes; and the estimated impact of contingencies and ongoing litigation. While management believes that such 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, Policy [Policy Text Block]	Revenue Recognition Revenue under construction contracts is accounted for under the percentage-of-completion method of accounting. Under the percentage-of-completion method, the Company estimates profit as the difference between total estimated revenue and total estimated cost of a contract and recognizes that profit over the contract term based on costs incurred. Contract costs include all direct materials, labor and subcontracted costs and those indirect costs related to contract performance, such as indirect labor, supplies, tools, repairs, depreciation and the operational costs of capital equipment. The Company also has unit-price contracts that were not significant as of September 30, 2019 . The estimation process for revenue recognized under the percentage-of-completion method is based on the professional knowledge and experience of the Company’s project managers, engineers and financial professionals. Management reviews estimates of contract revenue and costs on an ongoing basis. Changes in job performance, job conditions and management’s assessment of expected contract settlements are factors that influence estimates of total contract value and total costs to complete those contracts and, therefore, the Company’s profit recognition. Changes in these factors may result in revisions to revenue, costs and income, and their effects are recognized in the period in which the revisions are determined, which could materially affect the Company’s results of operations in the period in which such changes are recognized. Revenue derived from projects billed on a fixed-price basis totaled 98.5% and 99.8% of consolidated revenue from operations for the three months ended September 30, 2019 and 2018 , respectively, and totaled 94.1% and 97.4% for the nine months ended September 30, 2019 and 2018, respectively. Revenue and related costs for construction 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 also accounted for under the percentage of completion method totaled 1.5% and 0.2% of consolidated revenue from operations for the three months ended September 30, 2019 and 2018 , respectively, and totaled 5.9% and 2.6% for the nine months ended September 30, 2019 and 2018 , respectively. For an approved change order which can be reliably estimated as to price, the anticipated revenues and costs associated with the change order are added to the total contract value and total estimated costs of the project, respectively. When costs are incurred for a) an unapproved change order which is probable to be approved or b) an approved change order which cannot be reliably estimated as to price, the total anticipated costs of the change order are added to both the total contract value and total estimated costs for the project. Once a change order becomes approved and reliably estimable, any margin related to the change order is added to the total contract value of the project. The Company actively engages in substantive meetings with its customers to complete the final approval process and generally expects these processes to be completed within a year. The amounts ultimately realized upon final acceptance by its customers could be higher or lower than such estimated amounts. Provisions for losses on uncompleted contracts are made in the period in which such losses become evident. The Company may incur costs subject to change orders, whether approved or unapproved by the customer, and/or claims related to certain contracts. Management determines the probability that such costs will be recovered based upon engineering studies and legal opinions, past practices with the customer and specific discussions, correspondence and/or preliminary negotiations with the customer. Classification of Construction Contract-Related Assets and Liabilities Contract costs include all direct subcontract, material, and labor costs, and those indirect costs related to contract performance, such as indirect labor, supplies, tools, insurance, repairs, maintenance, communications, and use of Company-owned equipment. Contract revenues are earned and matched with related costs as incurred. Costs and estimated earnings in excess of billings on uncompleted contracts are presented as a current asset in the accompanying condensed consolidated balance sheets, and billings in excess of costs and estimated earnings on uncompleted contracts are presented as a current liability in the accompanying condensed consolidated balance sheets. The Company’s contracts vary in duration, with the duration of some larger contracts exceeding one year. Consistent with industry practices, the Company includes the amounts realizable and payable under contracts, which may extend beyond one year, in current assets and current liabilities. These contract balances are generally settled within one year.
New Accounting Pronouncements, Policy [Policy Text Block]	New Accounting Pronouncements The effective dates shown in the following pronouncements are based on the Company's current status as an “emerging growth company.” In May 2014, the Financial Accounting Standards Board ("FASB") issued guidance on the recognition of revenue from contracts with customers. The core principle of the guidance is that a company should recognize revenue to depict the transfer of promised goods or services to customers in an amount that reflects the consideration which the company expects to receive in exchange for those goods or services. To achieve this core principle, the guidance provides a five-step analysis of transactions to determine when and how revenue is recognized. The guidance addresses several areas including transfer of control, contracts with multiple performance obligations, and costs to obtain and fulfill contracts. The guidance also requires additional disclosure about the nature, amount, timing, and uncertainty of revenue and cash flows arising from customer contracts, including significant judgments and changes in judgments and assets recognized from costs incurred to obtain or fulfill a contract. The standard will be effective for our fiscal year 2019 annual financial statements and for interim periods beginning in fiscal year 2020. The Company has substantially completed its assessment of the potential effects of these ASUs on its consolidated financial statements, business processes, systems and controls. The Company’s assessment included a detailed review of representative contracts at each of the Company’s segments and a comparison of its historical accounting policies and practices to the new standard. Based on the Company’s review of various types of revenue arrangements, the Company expects to recognize revenue and earnings over time utilizing the cost-to-cost measure of progress for its fixed price contracts and other service agreements, consistent with current practice. For these contracts, the cost-to-cost measure of progress best depicts the transfer of control of goods or services to the customer under the new standard. The Company has substantially completed its analysis of the information necessary to enable the preparation of the financial statements and related disclosures under the new standard. As part of this analysis, the Company evaluated its information technology capabilities and systems, and does not expect to incur significant information technology costs to modify systems currently in place. The Company will implement targeted changes to its internal reporting processes to facilitate gathering the data needed for reporting and disclosure under the new standard. The Company will also implement updates to its control processes and procedures, as necessary, based on changes resulting from the new standard. The Company does not expect any such updates to materially affect the Company’s internal controls over financial reporting. The Company anticipates adopting the standard using the modified retrospective transition approach. Under this approach, the new standard would apply to all new contracts initiated on or after January 1, 2019. For existing contracts that have remaining obligations as of January 1, 2019, any difference between the recognition criteria in these ASUs and the Company’s current revenue recognition practices would be recognized using a cumulative effect adjustment to the opening balance of retained earnings. Any potential effect of adoption of these ASUs has not yet been quantified; however, the Company anticipates the adoption will have an impact on both the amount and timing of revenue recognition related to unapproved change orders. The Company is training its impacted employees in business segments for the implementation of the new standard, and continues developing the disclosures required by the new standard. The Company is also reviewing certain contracts entered into by its business segments subsequent to its initial assessment that are expected to have performance obligations remaining as of January 1, 2019 for any cumulative effect adjustments that may be required upon adoption. In February 2016, the FASB issued ASU 2016-02, Leases (Topic 842) . Under ASU 2016-02, lessees will be required to recognize the following for all leases (with the exception of short-term leases) at the commencement date: 1) a lease liability, which is a lessee’s obligation to make lease payments arising from a lease, measured on a discounted basis, and 2) a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. ASU 2016-02 required entities to adopt the new leases standard using a modified retrospective method and initially apply the related guidance at the beginning of the earliest period presented in the financial statements. During July 2018, the FASB issued ASU 2018-11, which allows for an additional and optional transition method under which an entity would record a cumulative-effect adjustment at the beginning of the period of adoption. See Note 10. Commitments and Contingencies for additional information about our leases. The Company will early adopt the standard and it will be effective for our fiscal year 2019 annual financial statements and for interim periods beginning in fiscal year 2020. The Company is in the process of implementing leasing software to assist in the integration of the future standard. In August 2018, the FASB issued ASU 2018-13, Fair Value Measurement (Topic 820) , Disclosure Framework - Changes to the Disclosure Requirements for Fair Value Measurement, which eliminates certain disclosure requirements for recurring and non-recurring fair value measurements, such as the amount of and reason for transfers between Level 1 and Level 2 of the fair value hierarchy, and adds new disclosure requirements for Level 3 measurements. ASU 2018-13 is effective for all entities for fiscal years beginning after December 15, 2019, including interim periods within those fiscal years, with early adoption permitted for any eliminated or modified disclosures. Certain disclosures per ASU 2018-13 are required to be applied on a retrospective basis and others on a prospective basis. The Company is currently assessing the impact these changes will have on its disclosure requirements for fair value measurement. 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.

Acquisitions Business Combinati

Acquisitions Business Combination, Assets Acquired and Liabilities Assumed (Tables)	9 Months Ended
	Sep. 30, 2019
Business Acquisition [Line Items]
Schedule of Business Acquisitions, by Acquisition [Table Text Block]	The following table summarizes the amounts recognized for assets acquired and liabilities assumed as of the acquisition dates at fair value. The values for CCS were finalized as of June 30, 2019 and finalized for William Charles as of September 30, 2019. Identifiable assets acquired and liabilities assumed (in thousands) CCS William Charles Cash $ 6,413 $ 6,641 Accounts Receivable 58,041 69,740 Costs and estimated earnings in excess of billings on uncompleted contracts 9,512 16,095 Other current assets 1,813 7,999 Property, plant and equipment 59,952 47,899 Intangible assets: Customer relationships 19,500 7,000 Backlog 8,400 5,500 Tradename 8,900 4,500 Deferred income taxes (2,361 ) — Other non-current assets 134 75 Accounts payable and accrued liabilities (25,219 ) (60,962 ) Billings in excess of costs and estimated earnings on uncompleted contracts (14,194 ) (14,810 ) Debt, less current portion (52,257 ) (15,672 ) Capital lease obligations (1,124 ) — Other liabilities (704 ) (907 ) Total identifiable assets 76,806 73,098 Goodwill 29,773 4,581 Total purchase consideration $ 106,579 $ 77,679 * - There were no measurement period adjustments for the quarter ended September 30, 2019.
Business Acquisition, Pro Forma Information [Table Text Block]	The following table provides the supplemental unaudited actual and pro forma total revenue and net income of the combined entity had the acquisition date of CCS and William Charles been the first day of our fiscal year 2018: Three months ended September 30, Nine months ended September 30, (in thousands) Actual 2019 Pro forma 2018 Actual 2019 Pro forma 2018 Revenue 422,022 446,557 940,793 948,543 Net income (loss) 12,609 6,016 (4,072 ) (15,448 ) Net income (loss) per common share: Basic earnings per share 0.37 0.25 (1.44 ) (0.77 ) Diluted earnings per share 0.24 0.24 (1.44 ) (0.77 ) The amounts in the supplemental unaudited pro forma 2018 results apply the Company's accounting policies and reflect certain adjustments to, among other things, (i) exclude the impact of transaction costs incurred in connection with the acquisitions, (ii) include additional depreciation and amortization that would have been charged assuming the same fair value adjustments to property, plant and equipment and acquired intangibles had been applied on January 1, 2018, and (iii) include additional interest expense that would have been incurred assuming the incremental borrowings the Company incurred to finance the acquisitions had been outstanding on January 1, 2018. Accordingly, these supplemental unaudited pro forma results have been prepared for comparative purposes only and are not intended to be indicative of the results of operations that would have occurred had the acquisitions actually occurred in the prior year period or indicative of the results of operations for any future period. These results do not include any potential operating efficiencies and cost savings. The following table summarizes the results of operations included in the Company's condensed consolidated statement of operations for CCS and William Charles from their respective dates of acquisition. (in thousands) Three months ended September 30, 2019 Nine months ended September 30, 2019 CCS William Charles CCS William Charles Revenue 81,248 84,033 211,117 198,879 Net income (loss) 2,707 7,308 616 7,359 Three months ended September 30, 2018 Nine months ended September 30, 2018 CCS William Charles CCS William Charles Revenue 5,600 — 5,600 — Net income (loss) — — — —

Earnings per share (Tables)

Earnings per share (Tables)	9 Months Ended
	Sep. 30, 2019
Earnings Per Share [Abstract]
Schedule of basic and diluted EPS	The calculations of basic and diluted EPS, are as follows ($ in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Numerator: Net income (loss) 12,609 5,736 (4,072 ) (6,741 ) Less: Convertible Preferred Stock dividends (759 ) (524 ) (2,202 ) (1,072 ) Less: Contingent consideration fair value adjustment (see Note 8) (4,247 ) — (23,082 ) — Net income (loss) available to common stockholders 7,603 5,212 (29,356 ) (7,813 ) Denominator: Weighted average common shares outstanding - basic (1) 20,446,811 21,577,650 20,425,801 21,577,650 Series B Preferred - Warrants 2,845,840 — — — Convertible Series A Preferred Stock 11,486,534 3,522,438 — — Restricted stock units 640,247 — — — Weighted average shares for diluted computation 35,419,432 25,100,088 20,425,801 21,577,650 Anti-dilutive: (2)(3) Convertible Series A Preferred — — 8,968,856 2,832,765 Series B Preferred - Warrants at closing — — 1,325,779 — RSUs — — 542,421 — Basic EPS 0.37 0.24 (1.44 ) (0.36 ) Diluted EPS 0.24 0.23 (1.44 ) (0.36 ) (1) The contingent earn-out shares were not included at September 30, 2019 and were removed from September 30, 2018, respectively. See Note 8. Fair Value of Financial Instruments for discussion regarding the Company's contingently issuable earn-out shares. (2) Warrants to purchase 8,480,000 shares of common stock at $11.50 per share were outstanding at September 30, 2019 and 2018 but were not potentially dilutive as the warrants’ exercise price was greater than the average market price of the common stock during the period. 646,405 of vested and unvested Options and 817,817 of unvested RSUs were also not potentially dilutive as of September 30, 2019 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. (3) The 1.8 million unvested earnout shares were not included at September 30, 2019 due to the exercise price being greater than the average market price of the common stock during the period.

Accounts receivable, net of a_2

Accounts receivable, net of allowance (Tables)	9 Months Ended
	Sep. 30, 2019
Receivables [Abstract]
Schedule of accounts receivable and allowance for doubtful accounts	The following table provides details of accounts receivable, net of allowance as of the dates indicated (in thousands): September 30, 2019 December 31, 2018 Contract receivables $ 168,413 $ 161,408 Contract retainage 76,103 64,000 Accounts receivable, gross 244,516 225,408 Less: allowance for doubtful accounts (51 ) (42 ) Accounts receivable, net $ 244,465 $ 225,366 Included in costs in excess of billings as of September 30, 2019 are unapproved change orders of approximately $21.0 million for which the Company is pursuing settlement through dispute resolution. Activity in the allowance for doubtful accounts for the periods indicated is as follows (in thousands): Three Months Ended Nine Months Ended September 30, September 30, 2019 2018 2019 2018 Allowance for doubtful accounts at beginning of period $ 102 $ 216 $ 42 $ 216 Plus: provision for allowances 30 — 90 — Less: write-offs, net of recoveries (81 ) — (81 ) — Allowance for doubtful accounts at period end $ 51 $ 216 $ 51 $ 216

Contracts in progress (Tables)

Contracts in progress (Tables)	9 Months Ended
	Sep. 30, 2019
Contractors [Abstract]
Costs in excess of billings and billings in excess of costs	Contracts in progress were as follows as of the dates indicated (in thousands): September 30, 2019 December 31, 2018 Costs on contracts in progress $ 1,189,496 $ 935,820 Estimated earnings on contracts in progress 111,451 76,883 Revenue on contracts in progress 1,300,947 1,012,703 Less: billings on contracts in progress (1,263,221 ) (1,027,816 ) Net underbillings (overbillings) $ 37,726 $ (15,113 ) The above amounts have been included in the accompanying condensed consolidated balance sheets under the following captions (in thousands): September 30, 2019 December 31, 2018 Costs and estimated earnings in excess of billings on uncompleted contracts $ 109,540 $ 47,121 Billings in excess of costs and earnings on uncompleted contracts (71,814 ) (62,234 ) Net underbillings (overbillings) $ 37,726 $ (15,113 )

Property, plant and equipment_2

Property, plant and equipment, net (Tables)	9 Months Ended
	Sep. 30, 2019
Property, Plant and Equipment [Abstract]
Schedule of property plant and equipment	Property, plant and equipment, net consisted of the following (in thousands): September 30, 2019 December 31, 2018 Buildings and leasehold improvements $ 2,812 $ 4,614 Land 17,600 19,394 Construction equipment 178,239 175,298 Office equipment, furniture and fixtures 3,449 2,994 Vehicles 5,985 4,991 208,085 207,291 Accumulated depreciation (56,301 ) (31,113 ) Property, plant and equipment, net $ 151,784 $ 176,178

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets, net (Tables)	9 Months Ended
	Sep. 30, 2019
Goodwill and Intangible Assets, Net [Abstract]
Components of and changes in carrying amount of goodwill [Table Text Block]	The following table provides the changes in the carrying amount of goodwill for 2019 and 2018: (in thousands) Goodwill January 1, 2018 (Renewables Segment) $ 3,020 Acquisitions (Specialty Civil Segment) 37,237 December 31, 2018 $ 40,257 Acquisition adjustments (Specialty Civil Segment) (2,884 ) September 30, 2019 $ 37,373
Schedule of Finite-Lived Intangible Assets [Table Text Block]	Intangible assets, net consisted of the following as of the dates indicated: September 30, 2019 December 31, 2018 ($ 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 $ (3,749 ) $ 22,751 6 years $ 27,000 $ (814 ) $ 26,186 7 years Trade name 13,400 (2,635 ) 10,765 4 years 13,400 (575 ) 12,825 5 years Backlog 13,900 (6,791 ) 7,109 1 year 13,400 (1,537 ) 11,863 2 years $ 53,800 $ (13,175 ) $ 40,625 $ 53,800 $ (2,926 ) $ 50,874
Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]	The following table provides the annual intangible amortization expense currently expected to be recognized for the years 2019 through 2023: (in thousands) Remainder of 2019 2020 2021 2022 2023 Amortization expense $ 3,354 $ 11,837 $ 6,466 $ 6,466 $ 5,841

Fair value of financial instr_2

Fair value of financial instruments (Tables)	9 Months Ended
	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Schedule of fair value of liabilities measured on recurring basis	The following table sets forth information regarding the Company's assets measured at fair value on a recurring basis (in thousands): Fair Value Measurements at Reporting Date Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities as of December 31, 2018 Contingent consideration 23,082 — — 23,082 Fair Value Measurements at Reporting Date Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities as of September 30, 2019 Contingent consideration — — — — Series B-1 Preferred Stock - Series A Conversion Warrants 4,200 — — 4,200 Series B-1 Preferred Stock - Additional 6% Warrants 400 — — 400
Schedule of reconciliation of fair value unobservable liabilities measured on recurring basis	The following is a reconciliation of the beginning and ending balances for the periods indicated of recurring fair value measurements using Level 3 inputs (in thousands): Contingent Consideration Series B Preferred - Series A Conversion Warrants Series B Preferred - Additional 6% Warrants Beginning Balance, December 31, 2018 23,082 $ — $ — Preferred Series B-1 Stock - Additional Warrants — 4,200 400 Fair value adjustment (23,082 ) — — Ending Balance, September 30, 2019 — 4,200 400
Schedule of liabilities measured at fair value on a non-recurring basis	The following table sets forth information regarding the Company's assets measured at fair value on a non-recurring basis (in thousands): Fair Value Measurements Amount recorded on balance sheet Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Liabilities: Series B-1 and Series B-2 Preferred Stock 81,300 — — 81,300 Equity: Series B-1 Preferred Stock - Warrants at closing 14,100 — — 14,100

Debt (Tables)

Debt (Tables)	9 Months Ended
	Sep. 30, 2019
Debt Disclosure [Abstract]
Schedule of debt	Debt consists of the following obligations as of: September 30, 2019 December 31, 2018 Term loan 277,688 300,000 Line of credit — 46,500 Commercial equipment notes 3,820 5,341 Total principal due for long-term debt 281,508 351,841 Unamortized debt discount and issuance costs (23,783 ) (23,534 ) Less: Current portion of long-term debt (31,119 ) (32,580 ) Long-term debt, less current portion 226,606 295,727 Debt - Series B Preferred Stock (1) 104,135 — Unamortized debt discount and issuance costs (27,369 ) — Long-term Series B Preferred Stock 76,766 —
Contractual maturities of debt and capital lease obligations	Contractual Maturities Contractual maturities of the Company's debt and capital lease (see Note 10. Commitments and Contingencies) obligations as of September 30, 2019 (in thousands): Remainder of 2019 $ 13,965 2020 55,988 2021 51,826 2022 47,276 2023 32,905 Thereafter 257,591 Total contractual obligations $ 459,551

Concentrations (Tables)

Concentrations (Tables)	9 Months Ended
	Sep. 30, 2019
Risks and Uncertainties [Abstract]
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 % Accounts Receivable % Three Months Ended Nine Months Ended September 30, September 30, September 30, 2019 December 31, 2018 2019 2018 2019 2018 Company A * 24.1 % * 22.6 % * 20.0 % Company B * 16.7 % * 12.1 % * * Company C * * 11.7 % * * 19.0 % Company D * 11.7 % * * * * * Amount was not above 10% threshold

Segments (Tables)

Segments (Tables)	9 Months Ended
	Sep. 30, 2019
Segment Reporting Information [Line Items]
Reconciliation of Revenue from Segments to Consolidated [Table Text Block]	Segment Revenue Revenue by segment was as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2019 2018 2019 2018 Segment Revenue % of Total Revenue Revenue % of Total Revenue Revenue % of Total Revenue Revenue % of Total Revenue Renewables $ 242,654 57.5 % $ 262,477 94.0 % $ 496,863 52.8 % $ 480,362 95.4 % Specialty Civil 179,368 42.5 % 16,802 6.0 % 443,930 47.2 % 23,125 4.6 % Total revenue $ 422,022 100.0 % $ 279,279 100.0 % $ 940,793 100.0 % $ 503,487 100.0 %
Reconciliation of Other Significant Reconciling Items from Segments to Consolidated [Table Text Block]	Segment Gross Profit Gross profit by segment was as follows: Three months ended September 30, Nine months ended September 30, (in thousands) 2019 2018 2019 2018 Segment Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Gross Profit Gross Profit Margin Renewables $ 27,469 11.3 % $ 24,822 9.5 % $ 45,806 9.2 % $ 37,578 7.8 % Specialty Civil 25,401 14.2 % 2,186 13.0 % 45,259 10.2 % 3,144 13.6 % Total gross profit $ 52,870 12.5 % $ 27,008 9.7 % $ 91,065 9.7 % $ 40,722 8.1 %

Related party transactions (Tab

Related party transactions (Tables)	9 Months Ended
	Sep. 30, 2019
Related Party Transactions [Abstract]
Schedule of related party shareholders	Related Party Shareholders Type of Equity Holder Ownership Percentage Series A Preferred Infrastructure and Energy Alternatives, LLC 100 % Series B-1 Preferred Stock, Series A Conversion Warrants, Additional 6% Warrants, Warrants at closing Ares 60 % Oaktree Power Opportunities Fund III Delaware, L.P. 40 % Contingent Consideration Infrastructure and Energy Alternatives, LLC 100 % Series B-2 Preferred Stock Ares 100 %

Business, Basis of Presentati_3

Business, Basis of Presentation and Significant Accounting Policies (Details) - Product Concentration Risk [Member] - 2019	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Fixed-price Contract [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	98.50%	99.80%	94.10%	97.40%
Time-and-materials Contract [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	1.50%	0.20%	5.90%	2.60%

Acquisitions (Details)

Acquisitions (Details) - USD ($) $ / shares in Units, $ in Millions	Nov. 02, 2018	Sep. 25, 2018
CCS [Member]
Business Acquisition [Line Items]
Purchase consideration for CCS		$ 106.6
William Charles [Member]
Business Acquisition [Line Items]
Purchase Consideration for William Charles	$ 77.7
Merger consideration paid	73.2
Business Acquisition, Equity Interest Issued or Issuable, Value Assigned	$ 4.5
Number of shares issued as consideration (in shares)	477,621
Business Acquisition, Share Price	$ 9.45

Acquisitions Acquisition of CCS

Acquisitions Acquisition of CCS and WC (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018	Nov. 02, 2018	Sep. 25, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill	$ 37,373						$ 37,373		$ 40,257			$ 3,020
Revenue	422,022			$ 279,279			940,793	$ 503,487
Net loss	12,609	$ 6,208	$ (22,889)	5,736	$ 4,915	$ (17,392)	(4,072)	(6,741)
Business Acquisition, Pro Forma Revenue	422,022			446,557			940,793	948,543
Business Acquisition, Pro Forma Net Income (Loss)	$ 12,609			$ 6,016			$ (4,072)	$ (15,448)
Business Acquisition, Pro Forma Earnings Per Share, Basic	$ 0.37			$ 0.25			$ (1.44)	$ (0.77)
Business Acquisition, Pro Forma Earnings Per Share, Diluted	$ 0.24			$ 0.24			$ (1.44)	$ (0.77)
CCS [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents											$ 6,413
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables											58,041
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Costs and Estimated Earnings in Excess of Billings											9,512
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets											1,813
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment											59,952
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Customer Relationships											19,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangibles Backlog											8,400
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangibles Tradename											8,900
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets											(2,361)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets											134
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accounts Payable and Accrued											(25,219)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Billings in excess of costs and estimated earnings on contracts											(14,194)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other											(52,257)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation											(1,124)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities											(704)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net											76,806
Goodwill											29,773
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net											$ 106,579
Goodwill, Nondeductible Portion, Amount	$ 2,900						$ 2,900
Revenue	81,248			$ 5,600			211,117	$ 5,600
Net loss	2,707			0			616	0
William Charles [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Cash and Equivalents										$ 6,641
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables										69,740
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Costs and Estimated Earnings in Excess of Billings										16,095
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Prepaid Expense and Other Assets										7,999
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment										47,899
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangible Customer Relationships										7,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangibles Backlog										5,500
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangibles Tradename										4,500
Business Combination Recognized Identifiable Assets Acquired and Liabilities Assumed, Deferred Tax Assets										0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Other Noncurrent Assets										75
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Accounts Payable and Accrued										(60,962)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Billings in excess of costs and estimated earnings on contracts										(14,810)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Other										(15,672)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Capital Lease Obligation										0
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Noncurrent Liabilities										(907)
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Net										73,098
Goodwill										4,581
Business Combination, Recognized Identifiable Assets Acquired, Goodwill, and Liabilities Assumed, Net										$ 77,679
Revenue	84,033			0			198,879	0
Net loss	$ 7,308			$ 0			$ 7,359	$ 0

Earnings per share - Basic and

Earnings per share - Basic and Diluted EPS (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended						9 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Sep. 30, 2019	Sep. 30, 2018
Numerator:
Net income (loss)	$ 12,609	$ 6,208	$ (22,889)	$ 5,736	$ 4,915	$ (17,392)	$ (4,072)	$ (6,741)
Less: Convertible Preferred Stock dividends	(759)			(524)			(2,202)	(1,072)
Business Combination, Contingent Consideration Arrangements, Change in Amount of Contingent Consideration, Liability	(4,247)			0			(23,082)	0
Net income (loss) available to common stockholders	$ 7,603			$ 5,212			$ (29,356)	$ (7,813)
Denominator:
Weighted Average Number of Shares Outstanding, Basic	20,446,811			21,577,650			20,425,801	21,577,650
Weighted Average Number of Shares Outstanding, Diluted	35,419,432			25,100,088			20,425,801	21,577,650
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Preferred Stock	11,486,534			3,522,438			8,968,856	2,832,765
Incremental Common Shares Attributable to Dilutive Effect of Call Options and Warrants	2,845,840						1,325,779	0
Incremental Common Shares Attributable to Dilutive Effect of Share-based Payment Arrangements	640,247						542,421	0
Entity Common Stock, Shares Outstanding	22,300,000						22,300,000
Basic EPS (in dollars per share)	$ 0.37			$ 0.24			$ (1.44)	$ (0.36)
Diluted EPS (in dollars per share)	0.24			$ 0.23			$ (1.44)	$ (0.36)
Warrant [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
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
Employee Stock Option [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount							646,000
Restricted Stock Units (RSUs) [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Antidilutive securities excluded from computation of earnings per share, amount							818,000
Performance Shares [Member]
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Earnout Shares removed from outstanding shares							1,800,000

Earnings per share - Narrative

Earnings per share - Narrative (Details) $ / shares in Units, $ in Thousands	Aug. 30, 2019	May 20, 2019USD ($)$ / shares	Mar. 26, 2018$ / sharesshares	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)	Sep. 30, 2019USD ($)$ / sharesshares	Sep. 30, 2018USD ($)	Dec. 31, 2018USD ($)$ / sharesshares
Class of Stock [Line Items]
stock price reduction on contingent consideration				80.00%		80.00%
Preferred stock, shares issued (in shares) | shares				34,965		34,965		34,965
Preferred stock, par value (in dollars per share) | $ / shares				$ 0.0001		$ 0.0001		$ 0.0001
Total consideration for shares issued at the closing of the Merger				$ 34,965		$ 34,965		$ 34,965
SeriesB Preferred Shares to be Issued in Equity Agreement | shares				100,000		100,000
Preferred Stock Dividends, Income Statement Impact				$ 759	$ 524	$ 2,202	$ 1,072
Share-based compensation expense				1,100	$ 500	2,812	$ 500
Series A Preferred Stock
Class of Stock [Line Items]
Preferred stock, shares issued (in shares) | shares			34,965
Preferred stock, par value (in dollars per share) | $ / shares			$ 1,000
Total consideration for shares issued at the closing of the Merger				$ 37,700		37,700
Preferred stock, dividend rate before deleveraging			6.00%
18 month anniversary date			18 months
Preferred stock, dividend rate thereafter			10.00%
Default Rate for Uncured Dividends			2.00%
Preferred Stock Paid In Kind Dividend Rate		8.00%
Series A Preferred PIK Dividend Rate 18 mos		12.00%
Preferred Stock, Dividends, Declared						$ 2,727
Series B Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, par value (in dollars per share) | $ / shares		$ 1,000		$ 1,000		$ 1,000
Preferred stock, dividend rate before deleveraging		15.00%
Preferred Stock Paid In Kind Dividend Rate		18.00%
Series B Cash Dividend Rate after Deleveraging		13.50%
Series B PIK Dividend Rate after Deleveraging		15.00%
Deleveraging Dollar Amount Used to Pay Debt		$ 50,000
Ratio Net Leverage Ratio for Deleveraging Event		1.50		1.50		1.50
Dividends Payable				$ 4,100		$ 4,100
Series B-2 Preferred Stock [Member]
Class of Stock [Line Items]
Preferred stock, dividend rate before deleveraging	15.00%
Series B Cash Dividend Rate after Deleveraging	13.50%
Ratio Net Leverage Ratio for Deleveraging Event	1.50
Dividend Rate after 1.5:1.0 leverage	12.00%

Accounts receivable, net of a_3

Accounts receivable, net of allowance - Accounts receivable, net of allowance (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Dec. 31, 2017
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	$ 244,516		$ 225,408
Less: allowance for doubtful accounts	(51)	$ (102)	(42)	$ (216)	$ (216)	$ (216)
Accounts receivable, net	244,465		225,366
Contract receivables
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	168,413		161,408
Contract retainage
Accounts, Notes, Loans and Financing Receivable [Line Items]
Accounts receivable, gross	$ 76,103		$ 64,000

Accounts receivable, net of a_4

Accounts receivable, net of allowance - Activity in the allowance for doubtful accounts (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Allowance for Doubtful Accounts Receivable [Roll Forward]
Allowance for doubtful accounts at beginning of period	$ 102	$ 216	$ 42	$ 216
Plus: provision for allowances	(30)	0	(90)	0
Provision for Doubtful Accounts	81	0	81	0
Allowance for doubtful accounts at period end	51	$ 216	51	$ 216
One Customer
Accounts, Notes, Loans and Financing Receivable [Line Items]
Contracts Receivable, Claims and Uncertain Amounts	$ 21,000		$ 21,000

Contracts in progress - Costs i

Contracts in progress - Costs in excess of billings and billings in excess of costs (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Contractors [Abstract]
Costs on contracts in progress	$ 1,189,496	$ 935,820
Estimated earnings on contracts in progress	111,451	76,883
Costs on contracts and estimated earnings on contracts in progress	1,300,947	1,012,703
Less: billings on contracts in progress	(1,263,221)	(1,027,816)
Costs and estimated earnings in excess of billings on uncompleted contracts	109,540	47,121
Billings in excess of costs and earnings on uncompleted contracts	(71,814)	(62,234)
Net underbillings (overbillings)	37,726	(15,113)
Provision for Loss on Contracts	100	1,400
Gross amount of unresolved change orders and claims	$ 69,900	$ 45,000

Property, plant and equipment_3

Property, plant and equipment, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 208,085		$ 208,085		$ 207,291
Accumulated depreciation	(56,301)		(56,301)		(31,113)
Property, plant and equipment, net	151,784		151,784		176,178
Depreciation expense	9,219	$ 2,471	26,125	$ 6,388
Buildings and leasehold improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	2,812		2,812		4,614
Land [Member]
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	17,600		17,600		19,394
Construction equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	178,239		178,239		175,298
Office equipment, furniture and fixtures
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	3,449		3,449		2,994
Vehicles
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 5,985		$ 5,985		$ 4,991

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets, net (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended		12 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Goodwill [Roll Forward]
Goodwill, Beginning Balance			$ 40,257	$ 3,020	$ 3,020
Goodwill, Acquired During Period					37,237
Goodwill, Purchase Accounting Adjustments			(2,884)
Goodwill, Ending Balance	$ 37,373		37,373		40,257
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	53,800		53,800		53,800
Finite-Lived Intangible Assets, Accumulated Amortization	(13,175)		(13,175)		(2,926)
Finite-Lived Intangible Assets, Net	40,625		40,625		50,874
Amortization of Intangible Assets	3,400	$ 100	10,300	$ 200
Finite-Lived Intangible Assets, Amortization Expense, Remainder of Fiscal Year	3,354		3,354
Finite-Lived Intangible Assets, Amortization Expense, Year Two	11,837		11,837
Finite-Lived Intangible Assets, Amortization Expense, Year Three	6,466		6,466
Finite-Lived Intangible Assets, Amortization Expense, Year Four	6,466		6,466
Finite-Lived Intangible Assets, Amortization Expense, Year Five	5,841		5,841
Customer Relationships [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	26,500		26,500		27,000
Finite-Lived Intangible Assets, Accumulated Amortization	(3,749)		(3,749)		(814)
Finite-Lived Intangible Assets, Net	22,751		$ 22,751		$ 26,186
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			6 years		7 years
Trade Names [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	13,400		$ 13,400		$ 13,400
Finite-Lived Intangible Assets, Accumulated Amortization	(2,635)		(2,635)		(575)
Finite-Lived Intangible Assets, Net	10,765		$ 10,765		$ 12,825
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			4 years		5 years
Order or Production Backlog [Member]
Finite-Lived Intangible Assets [Line Items]
Finite-Lived Intangible Assets, Gross	13,900		$ 13,900		$ 13,400
Finite-Lived Intangible Assets, Accumulated Amortization	(6,791)		(6,791)		(1,537)
Finite-Lived Intangible Assets, Net	$ 7,109		$ 7,109		$ 11,863
Acquired Finite-lived Intangible Assets, Weighted Average Useful Life			1 year		2 years

Fair value of financial instr_3

Fair value of financial instruments - Fair Value Liabilities Measured on Recurring Basis (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 0	$ 23,082
Fair value on a recurring basis
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		23,082
Fair value on a recurring basis | Business Combination, Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock - Series A Conversion Warrants	4,200
Fair value on a recurring basis | Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock - Additional 6% Warrants	400
Fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		0
Fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Business Combination, Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Significant Other Observable Inputs (Level 2)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		0
Fair value on a recurring basis | Significant Other Observable Inputs (Level 2) | Business Combination, Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Significant Other Observable Inputs (Level 2) | Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Significant Other Observable Inputs (Level 2) | Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Significant Unobservable Inputs (Level 3)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration		$ 23,082
Fair value on a recurring basis | Significant Unobservable Inputs (Level 3) | Business Combination, Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	0
Fair value on a recurring basis | Significant Unobservable Inputs (Level 3) | Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	4,200
Fair value on a recurring basis | Significant Unobservable Inputs (Level 3) | Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration	$ 400

Fair value of financial instr_4

Fair value of financial instruments - Reconciliation of Level 3 Inputs (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2019USD ($)
Business Combination, Contingent Consideration [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance, December 31, 2018	$ 23,082
Preferred Series B-1 Stock - Additional Warrants	0
Fair value adjustment	(23,082)
Ending Balance, September 30, 2019	0
Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance, December 31, 2018	0
Preferred Series B-1 Stock - Additional Warrants	4,200
Fair value adjustment	0
Ending Balance, September 30, 2019	4,200
Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Beginning Balance, December 31, 2018	0
Preferred Series B-1 Stock - Additional Warrants	400
Fair value adjustment	0
Ending Balance, September 30, 2019	$ 400

Fair value of financial instr_5

Fair value of financial instruments - Narrative (Details) - USD ($)	May 20, 2019	Sep. 30, 2019	Aug. 30, 2019	Jun. 30, 2019	Dec. 31, 2018	Mar. 26, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Initial Contingent Shares						9,000,000
stock price reduction on contingent consideration		80.00%
Share price (in dollars per share)				$ 2.04	$ 8.61
Preferred stock, par value (in dollars per share)		$ 0.0001			$ 0.0001
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 50,000,000
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock FV		$ 81,300,000
Business Combination, Contingent Consideration [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment		(23,082,000)
Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Share price (in dollars per share)	$ 4.21		$ 3.75
10% Warrants at Fully Diluted Share Count	10.00%
Series B Preferred Stock Warrant Exercise Price	$ 0.0001
Exercise price of securities excluded at closing (in dollars per share)	$ 11.50
Warrants Issued at Closing of Equity Agreement	2,545,934		900,000
Series B Preferred - Series A Conversion Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment		0
Share price (in dollars per share)	$ 4.21
Series B Preferred Stock Warrant Exercise Price	$ 0.0001
Series B Preferred - Additional 6% Warrants [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value adjustment		$ 0
6% Warrants	6.00%
Series B Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SeriesB Preferred Shares to be Issued in Equity Agreement	50,000
Preferred stock, par value (in dollars per share)	$ 1,000	$ 1,000

Fair value of financial instr_6

Fair value of financial instruments - Fair Value Liabilities Measured on Nonrecurring Basis (Details) - USD ($) $ / shares in Units, $ in Thousands	Aug. 30, 2019	May 20, 2019	Sep. 30, 2019	Jun. 30, 2019	Dec. 31, 2018
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Proceeds from Issuance of Preferred Stock and Preference Stock		$ 50,000
Share price (in dollars per share)				$ 2.04	$ 8.61
Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Warrants Issued at Closing of Equity Agreement	900,000	2,545,934
Share price (in dollars per share)	$ 3.75	$ 4.21
Fair Value, Measurements, Nonrecurring [Member] | Series B Preferred Stock Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock FV			$ 81,300
Fair Value, Measurements, Nonrecurring [Member] | Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock Warrants FV at closing			14,100
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Series B Preferred Stock FV			81,300
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B Preferred Stock Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			0
Fair Value, Measurements, Nonrecurring [Member] | Quoted Prices in Active Markets for Identical Assets (Level 1) | Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) | Series B Preferred Stock Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			0
Fair Value, Measurements, Nonrecurring [Member] | Significant Other Observable Inputs (Level 2) | Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			0
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) | Series B Preferred Stock Liability [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			81,300
Fair Value, Measurements, Nonrecurring [Member] | Significant Unobservable Inputs (Level 3) | Series B Preferred Stock Warrants at closing[Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Contingent consideration			$ 14,100
Series B-2 Preferred Stock [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
SeriesB Preferred Shares to be Issued in Equity Agreement	50,000
Proceeds from Issuance of Preferred Stock and Preference Stock	$ 50,000

Debt - Long-Term Debt (Details)

Debt - Long-Term Debt (Details) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Total principal due for long-term debt	$ 281,508	$ 351,841
Debt Issuance Costs, Net	(23,783)	(23,534)
Long-term Debt, Current Maturities	(31,119)	(32,580)
Long-term debt, less current portion	226,606	295,727
Debt - Series B Preferred Stock	76,766	0
Term Loan [Member]
Debt Instrument [Line Items]
Total principal due for long-term debt	277,688	300,000
Line of credit
Debt Instrument [Line Items]
Total principal due for long-term debt	0	46,500
Series B Preferred Stock Liability [Member]
Debt Instrument [Line Items]
Total principal due for long-term debt	104,135	0
Debt Issuance Costs, Net	(27,369)	0
Commercial equipment notes | Term Loan - Long Term [Member]
Debt Instrument [Line Items]
Total principal due for long-term debt	3,820	$ 5,341
Series B Preferred Stock [Member]
Debt Instrument [Line Items]
Dividends Payable	$ 4,100

Debt - Narrative (Details)

Debt - Narrative (Details) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Letters of credit contingently liable for	$ 20,981	$ 3,006
Surety bonds	$ 2,017,584	$ 1,681,983
Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Quarterly Amortization, Percentage Of Aggregate Principal Amount	2.50%
Debt Instrument, Additional Annual Payment Amount, Percentage Of Excess Cash Flows	75.00%
Debt Instrument, Covenant Terms, Additional Annual Payment Amount, Excess Cash Flow Threshold	$ 2,500
Percent of Initial Debt paid quarterly	2.50%
Line of credit
Debt Instrument [Line Items]
Debt, Weighted Average Interest Rate	10.42%	8.82%
Revolving Credit Facility [Member] | Third A&R Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate of debt	4.25%
Revolving Credit Facility [Member] | Third A&R Credit Agreement [Member] | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate of debt	3.25%
Consenting Lender [Member] | Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
First Net Lien Ratio for Lower Int Rate	2.67
Consenting Lender [Member] | Third A&R Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate of debt	8.25%
Consenting Lender [Member] | Third A&R Credit Agreement [Member] | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate of debt	7.25%
Consenting Lender Rate After 2.67 Lien Net Leverage [Member] | Third A&R Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate of debt	6.75%
Consenting Lender Rate After 2.67 Lien Net Leverage [Member] | Third A&R Credit Agreement [Member] | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate of debt	5.75%
Non-consenting Lender [Member] | Third A&R Credit Agreement [Member] | LIBOR
Debt Instrument [Line Items]
Basis spread on variable rate of debt	6.25%
Non-consenting Lender [Member] | Third A&R Credit Agreement [Member] | Base Rate
Debt Instrument [Line Items]
Basis spread on variable rate of debt	5.25%
Debt Covenant Period, Period Four [Member] [Member] | Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	2.25
Debt Covenant Period, Period Three [Member] [Member] | Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	2.75
Debt Covenant Period, Period Two [Member] | Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	3.50
Debt Covenant Period, Period One [Member] | Third A&R Credit Agreement [Member]
Debt Instrument [Line Items]
Debt Instrument, Covenant Terms, Maximum First Lien Net Leverage Ratio	4.75

Debt - Long Term Debt and Capit

Debt - Long Term Debt and Capital Lease Obligations (Details) $ in Thousands	Sep. 30, 2019USD ($)
Debt Disclosure [Abstract]
Remainder of 2019	$ 13,965
2020	55,988
2021	51,826
2022	47,276
2023	32,905
Thereafter	257,591
Contractual Obligation	$ 459,551

Commitments and contingencies -

Commitments and contingencies - Lease Narrative (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Capital lease obligations	$ 73,900		$ 73,900		$ 63,500
Capital leased assets, gross	119,600		119,600		76,900
Capital leased assets, accumulated depreciation	(29,300)		(29,300)		(10,100)
Capital leased assets, net	90,300		90,300		$ 66,800
Operating leases, rent expense	4,278	$ 496	9,519	$ 1,500
Other Commitments, Future Minimum Payments, Remainder of Fiscal Year	$ 3,200		3,200
Cost, Maintenance			3,200
Sale Leaseback Transaction, Gross Proceeds, Financing Activities			$ 25,000

Concentrations (Details)

Concentrations (Details) - Customer Concentration Risk [Member]	3 Months Ended	9 Months Ended		12 Months Ended
	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018	Dec. 31, 2018
2019 | Concentration Company A [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	24.10%		22.60%
2019 | Concentration Company B [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	16.70%		12.10%
2019 | Concentration Company C [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage		11.70%
2019 | Concentration Company D [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage	11.70%
Accounts Receivable % | Concentration Company A [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage				20.00%
Accounts Receivable % | Concentration Company C [Member]
Concentration Risk [Line Items]
Concentration Risk, Percentage				19.00%

Income taxes (Details)

Income taxes (Details) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Tax Contingency [Line Items]
Statutory federal tax rate			21.00%
Effective tax rates	(4.60%)	13.20%	43.00%	15.80%
Increase (decrease) in uncertain tax positions			$ 0	$ 0
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 ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Segment Reporting Information [Line Items]
Gross Profit	$ 52,870,000	$ 27,008,000	$ 91,065,000	$ 40,722,000
Gross profit margin	12.50%	9.70%	9.70%	8.10%
Revenue	$ 422,022,000	$ 279,279,000	$ 940,793,000	$ 503,487,000
Segment revenue as a percentage of total revenue	100.00%	100.00%	100.00%	100.00%
Renewables Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	$ 27,469,000	$ 24,822,000	$ 45,806,000	$ 37,578,000
Gross profit margin	11.30%	9.50%	9.20%	7.80%
Revenue	$ 242,654,000	$ 262,477,000	$ 496,863,000	$ 480,362,000
Segment revenue as a percentage of total revenue	57.50%	94.00%	52.80%	95.40%
Specialty Civil Segment [Member]
Segment Reporting Information [Line Items]
Gross Profit	$ 25,401,000	$ 2,186,000	$ 45,259,000	$ 3,144,000
Gross profit margin	14.20%	13.00%	10.20%	13.60%
Revenue	$ 179,368,000	$ 16,802,000	$ 443,930,000	$ 23,125,000
Segment revenue as a percentage of total revenue	42.50%	6.00%	47.20%	4.60%

Related party transactions (Det

Related party transactions (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Infrastructure And Energy Alternatives, LLC [Member]
Related Party Transaction [Line Items]
Series A Preferred Ownership Percentage	100.00%		100.00%
Contingent Consideration Ownership Percentage	100.00%		100.00%
ARES [Member]
Related Party Transaction [Line Items]
Series B Preferred Equity Agreement - All Equity Ares	60.00%		60.00%
Series B-2 Preferred Equity Agreement - Ares	100.00%		100.00%
Oaktree
Related Party Transaction [Line Items]
Series B Preferred Equity Agreement - All Equity Oaktree	40.00%		40.00%
Oaktree | Clinton Lease Agreement
Related Party Transaction [Line Items]
Expenses from transactions with related parties	$ 178	$ 153	$ 534	$ 459

Subsequent Event (Details)

Subsequent Event (Details) - USD ($)	Oct. 29, 2019	Sep. 30, 2019	Dec. 31, 2018
Subsequent Event [Line Items]
Preferred stock, par value (in dollars per share)		$ 0.0001	$ 0.0001
Subsequent Event
Subsequent Event [Line Items]
SeriesB Preferred Shares to be Issued in Equity Agreement	80,000
Warrants Issued at Closing of Equity Agreement	3,568,750
Equity Agreement Dollar Amount to be Funded	$ 80,000,000
12 day funding requirement	12 days
ECA half conditional shares	15,000
ECA Total Conditional Shares	30,000
HalfSeriesB-3WarrantsECA	515,625
Total Series B-3 Warrants After Initial Closing ECA	1,031,250
Maximum amount of consideration after initial closing ECA	$ 30,000,000
Shares available for purchase as part of rights offering	15,000
Warrant rate for conversion on rights offering	5.5
Dollar exchange rate series B-3 rights offering warrants	$ 160
Minimum investment for common to participate in tranche 2	50,000
Maximum percentage of common shareholders tranche 2	$ 2,250,000
Series A Exchange Percentage for Series B-3	50.00%
Preferred stock, par value (in dollars per share)	$ 1,000