Orion (ORN) 10-K 13 Mar 18 2017 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Mar. 09, 2018	Jun. 30, 2017
Document and Entity Information [Abstract]
Entity Registrant Name	ORION GROUP HOLDINGS INC.
Entity Central Index Key	1,402,829
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2017
Document Fiscal Year Focus	2,017
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		28,288,284
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 210.6

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Cash and cash equivalents	$ 9,086	$ 305
Accounts receivable:
Trade, net of allowance of $0 and $0, respectively	84,953	92,202
Retainage	39,189	40,201
Other current	3,706	4,634
Income taxes receivable	339	133
Inventory	4,386	5,392
Deferred tax asset	0	2,013
Costs and estimated earnings in excess of billings on uncompleted contracts	46,006	39,968
Assets held for sale	0	6,375
Prepaid expenses and other	4,124	3,885
Total current assets	191,789	195,108
Property and equipment, net	146,278	158,082
Accounts receivable, non-current	0	733
Inventory, non-current	4,915	3,998
Goodwill	69,483	66,351
Intangible assets, net of amortization	18,175	22,032
Other non-current	2,645	1,372
Total assets	433,285	447,676
Current liabilities:
Current debt, net of debt issuance costs	22,756	19,188
Accounts payable:
Trade	45,194	49,123
Retainage	1,990	893
Accrued liabilities	17,873	19,946
Taxes payable	256	689
Billings in excess of costs and estimated earnings on uncompleted contracts	33,923	27,681
Total current liabilities	121,992	117,520
Long-term debt, net of debt issuance costs	63,185	82,077
Other long-term liabilities	3,573	2,493
Deferred income taxes	13,243	19,000
Interest rate swap liability	26	382
Total liabilities	202,019	221,472
Stockholders’ equity:
Preferred stock -- $0.01 par value, 10,000,000 authorized, none issued	0	0
Other comprehensive loss	(26)	(382)
Common stock -- $0.01 par value, 50,000,000 authorized, 28,860,961 and 28,405,850 issued; 28,149,737 and 27,694,626 outstanding at December 31, 2017 and December 31, 2016, respectively	288	283
Treasury stock, 711,231 and 711,231 shares, at cost December 31, 2017 and December 31, 2016, respectively	(6,540)	(6,540)
Additional paid-in capital	174,697	171,079
Retained earnings	62,847	61,764
Total stockholders’ equity	231,266	226,204
Total liabilities and stockholders’ equity	$ 433,285	$ 447,676

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current assets:
Allowance for doubtful accounts	$ 0	$ 0
Stockholders' Equity:
Preferred stock, par value (in dollars per share)	$ 0.01	$ 0.01
Preferred stock, shares authorized	10,000,000	10,000,000
Preferred stock, shares issued	0	0
Common stock, par value (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized	50,000,000	50,000,000
Common stock, shares issued	28,860,961	28,405,850
Common stock, shares outstanding	28,149,737	27,694,626
Treasury stock, shares	(711,231)	(711,231)

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Statement [Abstract]
Contract revenues	$ 578,553	$ 578,236	$ 466,498
Costs of contract revenues	511,663	510,754	426,316
Gross profit	66,890	67,482	40,182
Selling, general and administrative expenses	66,026	64,987	47,715
Gain (Loss) on Disposition of Assets	(674)	(1,579)	466
Operating income (loss)	1,538	4,074	(7,999)
Other (expense) income:
(Gain) loss from sale of assets, net	674	1,579	(466)
Other income	41	59	536
Interest income	11	3	32
Interest expense	(5,731)	(6,175)	(3,148)
Other (expense) income, net	(5,679)	(6,113)	(2,580)
Loss before income taxes	(4,141)	(2,039)	(10,579)
Income tax (benefit) expense	(4,541)	1,581	(2,519)
Net income (loss)	$ 400	$ (3,620)	$ (8,060)
Basic income (loss) per share (USD per share)	$ 0.01	$ (0.13)	$ (0.29)
Diluted income (loss) per share (USD per share)	$ 0.01	$ (0.13)	$ (0.29)
Shares used to compute income (loss) per share
Basic (in shares)	28,029,936	27,536,967	27,366,528
Diluted (in shares)	28,354,280	27,536,967	27,366,528

Consolidated Statements of Comp

Consolidated Statements of Comprehensive (Loss) Income Statement - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Net income (loss)	$ 400	$ (3,620)	$ (8,060)
Change in fair value of cash flow hedge, net of tax expense of $53, net of tax expense of $25, and benefit of $90 for the years ended December 31, 2017, 2016 and 2015, respectively	356	(237)	(145)
Total comprehensive income (loss)	$ 756	$ (3,857)	$ (8,205)

Consolidated Statements of Com6

Consolidated Statements of Comprehensive (Loss) Income (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Statement of Comprehensive Income [Abstract]
Change in fair value of cash flow hedge, net of tax	$ 53	$ 25	$ (90)

Consolidated Statement of Stock

Consolidated Statement of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Other Comprehensive Income (Loss)	Additional Paid-In Capital	Retained Earnings
Beginning balance, shares at Dec. 31, 2014		27,969,783
Beginning balance at Dec. 31, 2014	$ 236,717	$ 279	$ (3,439)	$ 0	$ 166,433	$ 73,444
Beginning treasury stock, shares at Dec. 31, 2014			(361,231)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 2,275				2,275
Exercise of stock options, shares	3,970	3,970
Exercise of stock options	$ 28	$ 0			28
Issue restricted stock, shares		38,660
Cash flow hedge, net of tax	(145)			(145)
Forfeiture of restricted stock		19,824
Purchase of stock into treasury, shares			(350,000)
Purchase of shares into treasury	(3,101)		$ (3,101)
Net income (loss)	(8,060)					(8,060)
Ending balance, shares at Dec. 31, 2015		27,992,589
Ending balance at Dec. 31, 2015	227,714	$ 279	$ (6,540)	(145)	168,736	65,384
Ending treasury stock, shares at Dec. 31, 2015			(711,231)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 2,280				2,280
Exercise of stock options, shares	13,850	13,850
Exercise of stock options	$ 67	$ 0			67
Issue restricted stock, shares		407,002
Issuance of restricted stock	0	$ 4			(4)
Cash flow hedge, net of tax	(237)			(237)
Forfeiture of restricted stock		(7,591)
Net income (loss)	$ (3,620)					(3,620)
Ending balance, shares at Dec. 31, 2016	28,405,850	28,405,850
Ending balance at Dec. 31, 2016	$ 226,204	$ 283	$ (6,540)	(382)	171,079	61,764
Ending treasury stock, shares at Dec. 31, 2016	(711,231)		(711,231)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Stock-based compensation	$ 2,303				2,303
Exercise of stock options, shares	229,551	229,551
Exercise of stock options	$ 1,320	$ 2			1,318
Issue restricted stock, shares		345,913
Issuance of restricted stock	0	$ 3			(3)
Cash flow hedge, net of tax	356			356
Forfeiture of restricted stock		(120,353)
Net income (loss)	$ 400					400
Ending balance, shares at Dec. 31, 2017	28,860,961	28,860,961
Ending balance at Dec. 31, 2017	$ 231,266	$ 288	$ (6,540)	$ (26)	$ 174,697	62,847
Ending treasury stock, shares at Dec. 31, 2017	(711,231)		(711,231)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Deferred tax adjustments	$ 683					$ 683

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Cash flows from operating activities
Net income (loss)	$ 400	$ (3,620)	$ (8,060)
Adjustments to reconcile net loss to net cash provided by operating activities
Depreciation and amortization	29,491	34,162	28,083
Deferred financing cost amortization	1,269	1,225	462
Bad debt expense	0	0	22
Deferred income taxes	(4,166)	751	(2,885)
Stock-based compensation	2,303	2,280	2,275
(Gain) loss on sale of property and equipment	(674)	(1,579)	466
Change in operating assets and liabilities, net of effects of acquisitions:
Accounts receivable	15,022	(23,935)	(2,666)
Income tax receivable	(952)	(49)	249
Inventory	89	1,696	1,150
Accounts receivable, non-current	0	(511)	(222)
Prepaid expenses and other	(226)	856	(467)
Costs and estimated earnings in excess of billings on uncompleted contracts	(6,030)	19,640	(10,655)
Accounts payable	(5,666)	(5,717)	12,245
Accrued liabilities	(1,519)	(1,123)	1,658
Income tax payable	(433)	(125)	(1,097)
Billings in excess of costs and estimated earnings on uncompleted contracts	5,225	(802)	4,655
Deferred revenue	0	0	(34)
Net cash provided by operating activities	34,133	23,149	25,179
Cash flows from investing activities:
Proceeds from sale of property and equipment	6,826	2,152	2,708
Purchase of property and equipment	(10,729)	(18,715)	(20,802)
TBC acquisition adjustment	(557)	0	0
Insurance proceeds for PPE	925	0	0
Net cash used in investing activities	(10,080)	(17,686)	(128,795)
Cash flows from financing activities:
Borrowings from Credit Facility	72,000	57,000	149,021
Payments made on borrowings from Credit Facility	(87,813)	(63,084)	(42,955)
Extinguishment of debt	0	0	(32,427)
Loan costs from Credit Facility	(779)	(486)	(4,498)
Exercise of stock options	1,320	67	28
Purchase of shares into treasury	0	0	(3,101)
Net cash (used in) provided by financing activities	(15,272)	(6,503)	66,068
Net change in cash and cash equivalents	8,781	(1,040)	(37,548)
Cash and cash equivalents at beginning of year	305	1,345	38,893
Cash and cash equivalents at end of year	9,086	305	1,345
Supplemental disclosures of cash flow information, cash paid during the period for:
Interest	4,413	5,031	3,063
Taxes, net of refunds	1,008	999	584
Acquisition of TAS and purchase price adjustment
Cash flows from investing activities:
Payments for acquisition of businesses	0	(369)	(110,344)
Houston Industrial Tool Services, Inc.
Cash flows from investing activities:
Payments for acquisition of businesses	0	0	(357)
Acquisition of business in Pacific Northwest
Cash flows from investing activities:
Payments for acquisition of businesses	(6,000)	0	0
Acquisition of TW LaQuay Dredging [Member]
Cash flows from investing activities:
Payments for acquisition of businesses	$ (545)	$ (754)	$ 0

Description of Business and Bas

Description of Business and Basis of Presentation	12 Months Ended
	Dec. 31, 2017
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Description of Business and Basis of Presentation	Description of Business and Basis of Presentation Description of Business Orion Group Holdings, Inc., its subsidiaries and affiliates (hereafter collectively referred to as the "Company"), provide a broad range of specialty construction services in the infrastructure, industrial, and building sectors of the continental United States, Alaska, Canada and the Caribbean Basin. The Company’s marine segment services the infrastructure sector through marine transportation facility construction, marine pipeline construction, marine environmental structures, dredging of waterways, channels and ports, environmental dredging, design, and specialty services. Its concrete segment services the building sector by providing turnkey concrete services including pour and finish, dirt work, layout, forming, rebar, and mesh across the light commercial structural and other associated business areas. The Company is headquartered in Houston, Texas with offices throughout its operating areas. The tools used by the chief operating decision maker to allocate resources and assess performance are based on two reportable and operating segments: marine (formerly heavy civil marine construction), which operates under the Orion Marine Group brand and logo, and concrete (formerly commercial concrete construction), which operates under the TAS Commercial Concrete brand and logo. Although we describe the business in this report in terms of the services the Company provides, its base of customers and the areas in which it operates, the Company has determined that its operations currently comprise two reportable segments pursuant to FASB ASC Topic 280 - Segment Reporting . In making this determination, the Company considered the similar economic characteristics of its operations. For the marine construction segment, the methods used, and the internal processes employed, to deliver marine construction services are similar throughout the segment, including standardized estimating, project controls and project management. This segment has the same customers with similar funding drivers, and it complies with regulatory environments driven through Federal agencies such as the U.S. Army Corps of Engineers, U.S. Fish and Wildlife Service, EPA and OSHA, among others. Additionally, the segment is driven by macro-economic considerations including the level of import/export seaborne transportation, development of energy-related infrastructure, cruise line expansion and operations, marine bridge infrastructure development, waterway pipeline crossings and the maintenance of waterways. These considerations, and others, are key catalysts for future prospects and are similar across the segment. For our concrete segment, the Company also considered the similar economic characteristics of these operations. The methods used, and the internal processes employed to deliver our concrete construction services are similar throughout the segment, including standardized estimating, project controls and project management. This segment complies with regulatory environments such as OSHA. Additionally, this segment is driven by macro-economic considerations, including movements in population, commercial real estate development, institutional funding and expansion, and recreational developments, specifically in metropolitan areas of Texas. These considerations, and others, are key catalysts for future prospects and are similar across the segment. Basis of Presentation These consolidated financial statements include the accounts of the parent company, Orion Group Holdings, Inc. and its wholly-owned subsidiaries and have been prepared in accordance with U.S. GAAP. All intercompany balances and transactions have been eliminated in consolidation.

Summary of Significant Accounti

Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Summary of Significant Accounting Principles	Summary of Significant Accounting Principles The preparation of consolidated financial statements in conformity with U.S. GAAP requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the financial statements and the reported amounts of revenues and expenses during the reporting period. Management’s estimates, judgments and assumptions are continually evaluated based on available information and experience; however, actual amounts could differ from those estimates. On an ongoing basis, the Company evaluates the significant accounting policies used to prepare its consolidated financial statements, including, but not limited to, those related to: • Revenue recognition from construction contracts; • Accounts receivable and allowance for doubtful accounts; • Goodwill and other long-lived assets, testing for indicators of impairment; • Income taxes; • Self-insurance; and • Stock based compensation. Revenue Recognition For financial statement purposes, the Company records revenue on construction contracts using the percentage-of-completion method, measured by the percentage of actual contract costs incurred to date to total estimated costs for each contract. This method is used because management considers contract costs incurred to be the best available measure of progress on these contracts. Contract revenue is derived from the original contract price adjusted for agreed upon change orders. Contract costs include all direct costs, such as material and labor, and those indirect costs incurred that are related to contract performance such as payroll taxes and insurance. General and administrative costs are charged to expense as incurred. Incentive fees, if available, are billed to the customer based on terms and conditions of the contract. Pending claims are recognized as an increase in contract revenue only when the collection is deemed probable and if the amount can be reasonably estimated for purposes of calculating total profit or loss on long-term contracts. The Company records revenue and the unbilled receivable for project claims to the extent of costs incurred and to the extent management believes related collection is probable and includes no profit on claims recorded. As of December 31, 2017 , the Company recognized claims of approximately $12.3 million with customers. The Company believes collection of these claims is probable, although the full amount of the recorded claims may not be collected. Changes in job performance, job conditions and estimated profitability, including those arising from final contract settlements, may result in revisions to costs and revenues and are recognized in the period in which the revisions are determined. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are determined, without regard to the percentage of completion. Revenue is recorded net of any sales taxes collected and paid on behalf of the customer, if applicable. The current asset “costs and estimated earnings in excess of billings on uncompleted contracts” represents revenues recognized in excess of amounts billed, which management believes will be billed and collected within one year of the completion of the contract. The liability “billings in excess of costs and estimated earnings on uncompleted contracts” represents billings in excess of revenues recognized. The Company’s projects are typically short in duration, and usually span a period of less than one year. Historically, the Company has not had cause to combine or segment contracts. Classification of Current Assets and Liabilities The Company includes in current assets and liabilities amounts realizable and payable in the normal course of contract completion. Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. At times, cash held by financial institutions may exceed federally insured limits. The Company has not historically sustained losses on its cash balances in excess of federally insured limits. Cash equivalents at December 31, 2017 and 2016 consisted primarily of overnight bank deposits. Risk Concentrations Financial instruments that potentially subject the Company to concentrations of credit risk principally consist of accounts receivable. The Company depends on its ability to continue to obtain federal, state and local governmental contracts, and indirectly, on the amount of funding available to these agencies for new and current governmental projects. Therefore, a portion of the Company’s operations may be dependent upon the level and timing of government funding. Statutory mechanics liens provide the Company high priority in the event of lien foreclosures following financial difficulties of private owners, thus minimizing credit risk with private customers. Accounts Receivable Accounts receivable are stated at the historical carrying value, less allowances for doubtful accounts. The Company has significant investments in billed and unbilled receivables as of December 31, 2017 and 2016 . Billed receivables represent amounts billed upon the completion of small contracts and progress billings on large contracts in accordance with contract terms and milestone achievements. Unbilled receivables on contracts, which are included in costs in excess of billings, arise as revenues are recognized under the percentage-of-completion method. Unbilled amounts on contracts represent recoverable costs and accrued profits not yet billed. Revenue associated with these billings is recorded net of any sales tax, if applicable. Past due balances over 90 days and other higher risk amounts are reviewed individually for collectability. In establishing an allowance for doubtful accounts, the Company evaluates its contract receivables and costs in excess of billings and thoroughly reviews historical collection experience, the financial condition of its customers, billing disputes and other factors. The Company writes off uncollectible accounts receivable against the allowance for doubtful accounts if it is determined that the amounts will not be collected or if a settlement is reached for an amount that is less than the carrying value. As of December 31, 2017 and 2016 , the Company had not recorded an allowance for doubtful accounts. Balances billed to customers but not paid pursuant to retainage provisions in construction contracts generally become payable upon contract completion and acceptance by the owner. Retainage at December 31, 2017 totaled $39.2 million , of which $8.0 million is expected to be collected beyond 2018. Retainage at December 31, 2016 totaled $40.2 million . The Company negotiates change orders and claims with its customers. Unsuccessful negotiations of claims could result in a change to contract revenue that is less than amounts recorded, which could result in the recording of a loss. Successful claims negotiations could result in the recovery of previously recorded losses. Significant losses on receivables could adversely affect the Company’s financial position, results of operations and overall liquidity. Advertising Costs The Company primarily obtains contracts through the open bid process, and therefore advertising costs are not a significant component of expense. Advertising costs are expensed as incurred. Advertising expenses totaled $150,000 , $178,000 , and $114,000 in 2017 , 2016 and 2015 , respectively. Environmental Costs Costs related to environmental remediation are charged to expense. Other environmental costs are also charged to expense unless they increase the value of the property and/or provide future economic benefits, in which event the costs are capitalized. Environmental liabilities, if any, are recognized when the expenditure is considered probable and the amount can be reasonably estimated. The Company did not recognize any environmental liabilities as of December 31, 2017 or 2016 , respectively. Fair Value Measurements The Company evaluates and presents certain amounts included in the accompanying consolidated financial statements at “fair value” in accordance with U.S. GAAP, which requires the Company to base its estimates on assumptions that market participants, in an orderly transaction, would use to price an asset or liability, and to establish a hierarchy that prioritizes the information used to determine fair value. Refer to Note 8 for more information regarding fair value determination. The Company generally applies fair value valuation techniques on a non-recurring basis associated with (1) valuing assets and liabilities acquired in connection with business combinations and other transactions; (2) valuing potential impairment loss related to long-lived assets ; and (3) valuing potential impairment loss related to goodwill and indefinite-lived intangible assets. Inventory Current inventory consists of parts and small equipment held for use in the ordinary course of business and is valued at the lower of cost (using historical average cost) or net realizable value. Where shipping and handling costs are incurred by the Company, these charges are included in inventory and charged to cost of contract revenue upon use. Non-current inventory consists of spare parts (including engines, cutters and gears) that require special order or long-lead times for manufacture or fabrication, but must be kept on hand to reduce downtime. Refer to Note 7 for more information regarding inventory. Property and Equipment Property and equipment are recorded at cost. Ordinary maintenance and repairs that do not improve or extend the useful life of the asset are expensed as incurred. Major renewals and betterments of equipment are capitalized and depreciated generally over three to seven years until the next scheduled maintenance. When property and equipment are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in results of operations for the respective period. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets for financial statement purposes, as follows: Automobiles and trucks 3 to 5 years Buildings and improvements 5 to 30 years Construction equipment 3 to 15 years Vessels and other equipment 1 to 15 years Office equipment 1 to 5 years The Company generally uses accelerated depreciation methods for tax purposes where appropriate. Dry-docking costs are capitalized and amortized using the straight-line method over a period ranging from three to 15 years. Dry-docking costs include, but are not limited to, the inspection, refurbishment and replacement of steel, engine components, tailshafts, mooring equipment and other parts of the vessel. Amortization related to dry-docking activities is included as a component of depreciation. These costs and the related amortization periods are periodically reviewed to determine if the estimates are accurate. If warranted, a significant upgrade of equipment may result in a revision to the useful life of the asset, in which case the change is accounted for prospectively. Property and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or the fair value, less the costs to sell, and are no longer depreciated. There are no assets classified as held for sale as of December 31, 2017. Goodwill and Other Intangible Assets Goodwill The Company has acquired businesses and assets in purchase transactions that resulted in the recognition of goodwill. Goodwill represents the costs in excess of fair values assigned to the identifiable assets acquired and liabilities assumed in the acquisition. In accordance with U.S. GAAP, acquired goodwill is not amortized, but is subject to impairment testing at least annually at a reporting unit level (as of October 31 st of each year) or more frequently if events or circumstances indicate that the asset may be impaired. The Company determined that its operations comprise two reporting units for goodwill impairment testing, which match its two operating segments for financial reporting. Tests of impairment require a two-step process to be performed to analyze whether or not goodwill has been impaired. The first step of this test, used to identify potential impairment, compares the estimated fair value of a reporting unit with its carrying amount. The second step, if necessary, quantifies the impairment. The Company assesses the fair value of its reporting units based on a weighted average of valuations based on market multiples, discounted cash flows, and consideration of its market capitalization. The key assumptions used in the discounted cash flow valuations are discount rates, weighted average cost of capital and perpetual growth rates applied to cash flow projections. Also inherent in the discounted cash flow valuation models are past performance, projections and assumptions in current operating plans and revenue growth rates over the next five years. These assumptions contemplate business, market and overall economic conditions. Other considerations are assumptions that market participants may use in analysis of comparable companies. The underlying assumptions used for determining fair value, as discussed above, require significant judgment and are susceptible to change from period to period and could potentially cause a material impact to the income statement. In the future, the Company's estimated fair value could be negatively impacted by extended declines in our stock price, changes in macroeconomic indicators, sustained operating losses and other factors which may affect our assessment of fair value. See Note 9 for additional discussion of our goodwill and related goodwill impairment testing. Intangible assets Intangible assets that have finite lives are amortized. In addition, the Company evaluates the remaining useful life of intangible assets in each reporting period to determine whether events and circumstances warrant a revision of the remaining period of amortization. If the estimate of an intangible asset’s remaining life is changed, the remaining carrying value of such asset is amortized prospectively over that revised remaining useful life. Intangible assets that have indefinite lives are not amortized, but are subject to impairment testing at least annually or more frequently if events or circumstances indicate that the asset may be impaired. The Company has one indefinite-lived intangible asset, a trade name, which is tested for impairment annually on October 31 st , or whenever events or circumstances indicate that the carrying amount of the trade name may not be recoverable. Impairment is calculated as the excess of the trade name's carrying value over its fair value. The fair value of the trade name is determined using the relief from royalty method, a variation of the income approach. This method assumes that if a company owns intellectual property, it does not have to "rent" the asset and is, therefore, "relieved" from paying a royalty. Once a supportable royalty rate is determined, the rate is then applied to the projected revenues over the expected remaining life of the intangible assets to estimate the royalty savings. This approach is dependent on a number of factors, including estimates of future growth and trends, royalty rates, discount rates and other variables. See Note 9 for additional discussion of our intangible assets and trade name impairment testing. Stock-Based Compensation The Company recognizes compensation expense for equity awards over the vesting period based on the fair value of these awards at the date of grant. The computed fair value of these awards is recognized as a non-cash cost over the period the employee provides services, which is typically the vesting period of the award. The fair value of options granted is estimated on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model requires the use of subjective assumptions in the computation. Changes in these assumptions can cause significant fluctuations in the fair value of the option award. The fair value of restricted stock grants is equivalent to the fair value of the stock issued on the date of grant, and is measured as the mean price of the stock on the day of grant. Compensation expense is recognized only for share-based payments expected to vest. The Company estimates forfeitures at the date of grant based on historical experience and future expectations and this assessment is updated on a periodic basis. See Note 15 for further discussion of the Company’s stock-based compensation plan. Income Taxes The Company determines its consolidated income tax provision using the asset and liability method prescribed by U.S. GAAP, which requires the recognition of income tax expense for the amount of taxes payable or refundable for the current period and for deferred tax liabilities and assets for the future tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company must make significant assumptions, judgments and estimates to determine its current provision for income taxes, its deferred tax assets and liabilities, and any valuation allowance to be recorded against any deferred tax asset. The current provision for income tax is based upon the current tax laws and the Company’s interpretation of these laws, as well as the probable outcomes of any tax audits. The value of any net deferred tax asset depends upon estimates of the amount and category of future taxable income reduced by the amount of any tax benefits that the Company does not expect to realize. Actual operating results and the underlying amount and category of income in future years could render current assumptions, judgments and estimates of recoverable net deferred taxes inaccurate, thus impacting the Company’s financial position and results of operations. The Company computes deferred income taxes using the liability method. Under the liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Under the liability method, the effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. On December 22, 2017, the Act was enacted and signed into law. The Act makes broad and complex changes to the U.S. tax code that significantly affected the Company's income tax rate in 2017. The Act, among other things, reduces the U.S. federal corporate income tax rate from 35% to 21% ; limits the use of foreign tax credits to reduce U.S. income tax liability; eliminates the corporate alternative minimum tax ("AMT") and changes how existing AMT credits can be realized; allows immediate expensing for qualified assets; creates a new limitation on deductible interest expense; repeals the domestic production activities deduction; and limits the deductibility of certain executive compensation and other deductions. Given the widespread applicability of these changes to most U.S. companies, the SEC issued Staff Accounting Bulletin 118 (“SAB 118”) to assist registrants in addressing any uncertainty or diversity in views about the application of FASB ASC Topic 740, "Income Taxes" (ASC 740) in the period of enactment. SAB 118 provides registrants with the option of reporting a reasonable estimate for certain income tax effects of the Act in situations in which a company does not have the necessary information available, prepared or analyzed in reasonable detail to complete the accounting required under ASC 740. The reasonable estimate is reported as a provisional amount in the company’s financial statements during a “measurement period.” The measurement period begins in the reporting period that includes the Act’s enactment date (i.e. the Company’s fourth quarter of 2017) and ends when a company has obtained, prepared and analyzed the information needed in order to complete the accounting requirements under ASC 740. The measurement period should not extend beyond one year from the enactment date (i.e. December 22, 2018). During the measurement period, a company is expected to act in good faith to complete the accounting under ASC 740. Appropriate disclosures will be made to address the Company’s progress toward completing the accounting under the Act and ASC 740 during the measurement period as well as when the accounting is complete. See Note 13 for additional discussion regarding the Company’s application of SAB 118. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740-10 which prescribes a recognition threshold and measurement attribute for financial statement disclosure of tax positions taken, or expected to be taken, on its consolidated tax return. The Company evaluates and records any uncertain tax positions based on the amount that management deems is more likely than not to be sustained upon examination and ultimate settlement with the tax authorities in the tax jurisdictions in which it operates. Insurance Coverage The Company maintains insurance coverage for its business and operations. Insurance related to property, equipment, automobile, general liability, and a portion of workers' compensation is provided through traditional policies, subject to a deductible or deductibles. A portion of the Company's workers’ compensation exposure is covered through a mutual association, which is subject to supplemental calls. The marine segment maintains five levels of excess loss insurance coverage, totaling $200 million in excess of primary coverage. The marine segment's excess loss coverage responds to most of its policies when a primary limit of $1 million has been exhausted; provided that the primary limit for Contingent Maritime Employer’s Liability is $10 million and the Watercraft Pollution Policy primary limit is $5 million . The concrete segment maintains five levels of excess loss insurance coverage, totaling $200 million in excess of primary coverage. The concrete segment's excess loss coverage responds to most of its policies when a primary limit of $1 million has been exhausted. If a claim arises and a potential insurance recovery is probable, the impending gain is recognized separately from the related loss. The recovery will only be recognized up to the amount of the loss once the recovery of the claim is deemed probable and any excess gain will fall under contingency accounting and will only be recognized once it is realized. The Company does not net insurance recoveries against the related claim liability as the amount of the claim liability is determined without consideration of the anticipated insurance recoveries from third parties. Separately, the Company’s marine segment employee health care is provided through a trust administered by a third party. Funding of the trust is based on current claims. The administrator has purchased appropriate stop-loss coverage. Losses on these policies up to the deductible amounts are accrued based upon known claims incurred and an estimate of claims incurred but not reported. The accruals are derived from known facts, historical trends and industry averages to determine the best estimate of the ultimate expected loss. Actual claims may vary from estimates. Any adjustments to such reserves are included in the consolidated results of operations in the period in which they become known. The Company's concrete segment employee health care is provided through two policies. A fully funded policy is offered primarily to salaried employees and their dependents while a partially self-funded plan with an appropriate stop-loss is offered primarily to hourly employees and their dependents. The self-funded plan is funded to the maximum exposure and, as a result, expects to receive a partial refund after the policy expiration. The accrued liability for insurance includes incurred but not reported claims of $5.2 million at December 31, 2017 and 2016 , respectively. Warranty Costs Provision for estimated warranty costs, if any, is made in the period in which such costs become probable and is periodically adjusted to reflect actual experience. The Company historically has not been subject to significant warranty provisions and no such costs have been recorded in 2017, 2016 or 2015. Reclassifications Certain amounts in prior periods have been reclassified to conform with current period presentation. This includes an adjustment in prior periods to include debt issuance costs as a portion of debt on the balance sheet pursuant to the adoption of FASB Accounting Standard Update 2015-03, Simplifying the Presentation of Debt Issuance Costs . The Company also determined that a gain or loss on the sale of an asset should be included as part of operating income or loss instead of other expense or income on the income statement based on ASC 360-10-45-5. Finally, pursuant to guidance provided in the Act, the Company determined the amount of AMT credits should be included as part of non-current other assets instead of deferred tax assets on the balance sheet. Recent Accounting Pronouncements The FASB issues accounting standards and updates (each an "ASU") from time to time to its Accounting Standards Codification ("ASC"), which is the primary source of U.S. GAAP. The Company regularly monitors ASUs as they are issued and considers applicability to its business. All ASUs are adopted by their respective due dates and in the manner prescribed by the FASB. The following are those recently issued ASUs most likely to affect the presentation of the Company's consolidated financial statements: In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment. The FASB issued this update to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. The amendments in this update modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. The guidance should be applied on a prospective basis and is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted and the Company does not anticipate that the changes will materially impact the financial statements unless a goodwill impairment is recognized in the future. In February 2016, the FASB issued ASU 2016-02, Leases ( Topic 842 ). The Board issued this update to increase the transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The Company anticipates the most significant of the amendments to our organization to be the recognition of assets and liabilities by lessees for those leases classified as operating leases under previous U.S. GAAP. Under the new standard the Company will be required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods. In early 2017, the Company established a steering committee to analyze the potential impact of the new standard and identify potential differences that will result from adopting the standard. The Company is currently assessing the effects of adoption on its financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). This comprehensive new revenue recognition standard will supersede existing revenue guidance under U. S. GAAP. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Topic 606 will be effective for the Company beginning with its first quarter ending March 31, 2018. The guidance permits two methods of adoption: (1) retrospectively to each prior reporting period presented and the cumulative effect would be recognized at the earliest period shown (i.e. the full retrospective method); or (2) retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (i.e the modified retrospective method). The Company will adopt the standard using the modified retrospective method which will involve recognizing in beginning retained earnings an adjustment for the cumulative effect of the change and will be applied to contracts with customers that are not substantially complete as of January 1, 2018. The Company established a steering committee consisting of representatives from various business segments within the organization. The purpose of this committee was to analyze the impact of the new standard on the Company's business by reviewing the current revenue practices to identify potential differences that would result from applying the requirements of the new standard to revenue contracts. In addition, the Company analyzed the possibility of any necessary changes to current business processes, systems and controls to support recognition and disclosure under the new standard. Based on its assessment of the new standard as of December 31, 2017, the Company will continue to recognize revenue over time, measuring progress using the cost-to-cost method. It does not expect Topic 606 to have a material impact on its concrete segment’s revenue. The most significant impact of Topic 606 will be related to its marine segment, specifically in the following areas: • Multiple performance obligations - In accordance with Topic 606, construction contracts with customers, including those related to contract modifications will be reviewed to determine if there are multiple performance obligations. If separate performance obligations are identified, the timing of revenue recognition could be impacted. Based on our review of currently active construction contracts with customers, the Company identified certain contracts in the marine segment that have multiple performance obligations. However, based on its assessment, the Company does not believe the impact on retained earnings is material. • Upfront costs - In accordance with Topic 606, these costs are required to be capitalized as an asset and amortized over the duration of the related contract. For the Company, such costs are generally comprised of costs incurred to mobilize equipment and labor to a job site or other upfront costs such as bonds or insurance, which are expensed as incurred under current accounting practices. The Company identified certain currently active construction contracts in the marine segment with upfront costs. However, based on its assessment, the Company does not believe the impact on retained earnings is material. The Company also anticipates expanding our revenue re

Business Acquisition

Business Acquisition	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Business Acquisition	Business Acquisitions TBC Acquisition On April 9, 2017, T.A.S. Commercial Concrete Construction, LLC, a wholly owned subsidiary of Orion Group Holdings, Inc. ("the Company") entered into a Stock Purchase Agreement ("the Agreement") for the purchase of all the issued and outstanding shares (the "shares") of Tony Bagliore Concrete, Inc. ("TBC"), a Texas corporation. The Company and the two sole shareholders of TBC closed the purchase transactions on April 10, 2017 (the "Closing Date"). Upon the terms of and subject to the conditions set forth in the Agreement, the total aggregate consideration paid on the Closing Date by the Company to the Sellers for the shares was $6.0 million in cash. In addition however, if certain target considerations are met in future periods, an additional cash payment of up to $2.0 million will become payable to the Seller. The purpose of the acquisition was primarily to achieve growth by expanding the Company's current service offerings in addition to expansion into new markets. The tangible assets acquired include accounts receivable, retainage and fixed assets. The allocation of the estimated acquisition consideration is preliminary because initial accounting for this business combination is incomplete. The preliminary allocation is based on estimates, assumptions, valuations and other studies which have not progressed to a stage where there is sufficient information to make a definitive allocation. Accordingly, the acquisition consideration allocation purchase accounting adjustments will remain preliminary until the Company determines the final acquisition consideration allocation. The final amounts allocated to assets acquired and liabilities assumed could differ significantly from the amounts presented in the combined consolidated financial statements and are subject to change and may result in an increase or decrease in goodwill, particularly with any other working capital adjustments during the measurement period. This measurement period may extend up to one year from the acquisition date. Under the acquisition method of accounting, the total acquisition consideration is allocated to the acquired tangible and intangible assets and assumed liabilities of TBC based on their estimated fair values as of the closing of the acquisition. The table below outlines the total actual acquisition consideration allocated based on the preliminary fair values of TBC’s tangible and intangible assets and liabilities as of April 9, 2017: Accounts receivable $ 3,239 Retainage 1,860 Fixed assets, net 2,098 Other 9 Goodwill 2,562 Other intangible assets 878 Accounts payable (2,017 ) Accrued expenses and other current liabilities (1,080 ) Contingent consideration (456 ) Deferred tax liability (1,093 ) Total Acquisition Consideration at April 9, 2017 $ 6,000 Working capital adjustment (all attributable to Goodwill) 557 Total Acquisition Consideration $ 6,557 The excess of the acquisition consideration over the fair value of assets acquired and liabilities assumed was allocated to goodwill. The goodwill of $3.1 million arising from the acquisition consists primarily of synergies and business opportunities expected to be realized from the purchase of TBC. The goodwill is not deductible for income tax purposes. Finite-lived intangible assets acquired include customer relationships and contractual backlog. (See Note 9 ). The fixed assets acquired include construction equipment as well as automobiles and trucks and will be depreciated in accordance with Company policy, generally three to 15 years. As stated in the Agreement, the Company has agreed to pay the sellers up to $2.0 million in cash, if earned, as additional purchase consideration. The seller's right to receive the contingent consideration, if any, shall be based on the Company's achievement of certain future financial targets. The Company measured the fair value of the contingent consideration at the Acquisition Date, and determined that fair value to be approximately $0.5 million , as shown in the table above. This amount of contingent liability is classified on the Consolidated Balance Sheets as other long-term liabilities. Pro Forma Results (unaudited) The results and operations of TBC have been included in the Consolidated Statements of Operations since the acquisition date of April 9, 2017. The Company has calculated the pro forma impact of the acquisition of TBC in our operating results for the twelve months ended December 31, 2016. Pro Forma Results For the Year Ended December 31, 2016 Contract revenues $ 610,695 Operating income from continuing operations $ 5,593 Net loss $ (2,677 ) Basic loss per share $ (0.10 ) Diluted loss per share $ (0.10 ) The Company derived the pro forma results of the acquisition based upon historical financial information obtained from the seller and certain management assumptions. The pro forma adjustments related to incremental amortization expense associated with the acquired finite-lived intangible assets and interest expense associated with borrowings to effect the transaction, assuming a January 1, 2016 effective transaction date. In addition, the tax impact of these adjustments was calculated at a 35% statutory rate. These pro forma results are not indicative of the results that would have been obtained had the acquisition of TBC been completed on January 1 of the respective period, or that may be obtained in the future. TAS Acquisition On August 5, 2015, the Company completed its acquisition of all the issued and outstanding membership interests of T.A.S. Commercial Concrete Construction, LLC, T.A.S. Commercial Concrete Solutions, LLC, directly and indirectly all of the issued and outstanding membership interests of T.A.S. Proco, LLC, and 49% of the issued and outstanding membership interests of GLM Concrete Solutions, LLC, collectively known as "TAS" hereafter, which is headquartered in Houston, Texas, for approximately $112 million in cash. The purpose of the acquisition was primarily to achieve growth by expanding the Company's current service offerings in addition to expansion into new markets. The tangible assets acquired include accounts receivable, prepaid assets, work in progress and fixed assets. The excess acquisition consideration over the fair value of assets acquired and liabilities assumed was allocated to goodwill. The goodwill of $32.6 million , which included $0.4 million recorded in June 2016 for certain adjustments to post-closing items, arising from the acquisition consists primarily of synergies and business opportunities expected to be realized from the purchase of TAS. Goodwill for tax purposes is $32.6 million , which is amortizable over a 15 -year period. Pro Forma Results (unaudited) The Company has calculated the pro forma impact of the acquisition of TAS in our operating results for the twelve months ended December 31, 2015. The following pro forma results give effect to this acquisition, assuming the transaction occurred on January 1 of the respective period. Pro Forma Results For the Year Ended December 31, 2015 Contract Revenues $ 602,537 Operating income from continuing operations $ 1,541 Net Income $ 1,311 Basic earnings per share $ 0.05 Diluted earnings per share $ 0.05 The Company derived the pro forma results of the acquisition based upon historical financial information obtained from the sellers and certain management assumptions. The pro forma adjustments related to incremental amortization expense associated with the acquired finite-lived intangible assets and interest expense associated with borrowings to effect the transaction, assuming a January 1, 2015 effective transaction date. In addition, the tax impact of these adjustments was calculated at a 35% statutory rate. These pro forma results are not indicative of the results that would have been obtained had the acquisition of TAS been completed on January 1 of the respective period, or that may be obtained in the future.

Concentration of Risk and Enter

Concentration of Risk and Enterprise Wide Disclosures	12 Months Ended
	Dec. 31, 2017
Risks and Uncertainties [Abstract]
Concentration of Risk and Enterprise Wide Disclosures	Concentration of Risk and Enterprise Wide Disclosures Accounts receivable include amounts billed to governmental agencies and private customers and do not bear interest. Balances billed to customers but not paid pursuant to retainage provisions generally become payable upon contract completion and acceptance by the owner. The table below presents the concentrations of current receivables (trade and retainage) at December 31, 2017 and December 31, 2016 , respectively: December 31, 2017 December 31, 2016 Federal Government $ 3,509 3 % $ 5,542 4 % State Governments 4,503 3 % 9,302 7 % Local Governments 18,256 15 % 20,886 16 % Private Companies 97,874 79 % 96,673 73 % Total receivables $ 124,142 100 % $ 132,403 100 % At December 31, 2017 and 2016 , no single customer accounted for more than 10.0% of total current receivables. Additionally, the table below represents concentrations of contract revenue by type of customer for the year s ended December 31, 2017 , 2016 and 2015 . 2017 % 2016 % 2015 % Federal Government $ 63,823 11 % $ 40,361 7 % $ 45,439 10 % State Governments 42,613 7 % 37,700 7 % 42,026 9 % Local Governments 91,592 16 % 94,461 16 % 130,187 28 % Private Companies 380,525 66 % 405,714 70 % 248,846 53 % Total contract revenues $ 578,553 100 % $ 578,236 100 % $ 466,498 100 % In the year s ended December 31, 2017 , 2016 and 2015 , no single customer exceeded 10.0% of total contract revenues. The Company does not believe that the loss of any one of these customers would have a material adverse effect on the Company or its subsidiaries and affiliates since no single specific customer sustains such a large portion of receivables or contract revenue over time. In addition, the concrete segment primarily purchases concrete from select suppliers. The loss of one of these suppliers could adversely impact short-term operations. Contract revenues generated outside the United States totaled 1.6% , 1.3% and 4.1% of total revenues for the years ended December 31, 2017 , 2016 and 2015 , respectively, and were primarily located in the Caribbean Basin and Mexico.

Contracts in Progress

Contracts in Progress	12 Months Ended
	Dec. 31, 2017
Contractors [Abstract]
Contracts in Progress	Contracts in Progress Contracts in progress are as follows at December 31, 2017 and December 31, 2016 : December 31, December 31, Costs incurred on uncompleted contracts $ 668,848 $ 802,140 Estimated earnings 120,751 143,975 789,599 946,115 Less: Billings to date (777,516 ) (933,828 ) $ 12,083 $ 12,287 Included in the accompanying consolidated balance sheets under the following captions: Costs and estimated earnings in excess of billings on uncompleted contracts 46,006 $ 39,968 Billings in excess of costs and estimated earnings on uncompleted contracts (33,923 ) (27,681 ) $ 12,083 $ 12,287 Included in cost and estimated earnings in excess of billings on uncompleted projects is approximately $12.3 million related to claims and unapproved change orders. See Note 2 - Summary of Significant Accounting Principles to the Company's consolidated financial statements for discussion of these claims. Contract costs include all direct costs, such as materials and labor, and those indirect costs incurred that are related to contract performance such as payroll taxes and insurance. General and administrative costs are charged to expense as incurred. Incentive fees, if available, are billed to the customer based on the terms and conditions of the contract. Pending claims are recognized as an increase in contract revenue only when the collection is deemed probable and if the amount can be reasonably estimated for purposes of calculating total profit or loss on long-term contracts. Changes in job performance, job conditions and estimated profitability, including those arising from final contract settlements, may result in revisions to costs and revenues and are recognized in the period in which the revisions are determined. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are determined, without regard to the percentage of completion.

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following is a summary of property and equipment at December 31, 2017 and December 31, 2016 : December 31, December 31, Automobiles and trucks $ 1,940 $ 2,525 Building and improvements 38,062 37,269 Construction equipment 166,203 165,023 Vessels and other equipment 85,113 88,659 Office equipment 8,039 7,125 299,357 300,601 Less: accumulated depreciation (191,407 ) (181,293 ) Net book value of depreciable assets 107,950 119,308 Construction in progress 245 543 Land 38,083 38,231 $ 146,278 $ 158,082 For the years ended December 31, 2017 , 2016 and 2015 , depreciation expense was $24.8 million , $26.9 million and $23.7 million , respectively. Substantially all depreciation expense is included in the cost of contract revenue in the Company’s Consolidated Statements of Operations. Substantially all of the assets of the Company are pledged as collateral under the Company's Credit Agreement (as defined in Note 11 ). Substantially all of the Company’s long-lived assets are located in the United States. During 2015, the Company committed to a plan to review property and equipment within the marine segment and adopted a plan to dispose of underutilized assets. In connection with this disposal, the Company determined that the carrying value of certain of these assets exceeded its fair value, and consequently, the Company recorded an impairment loss of $1.7 million on those assets during 2015, which included any expected costs to sell. Additionally, various other assets were identified as underutilized and were sold for salvage value. The Company recorded an impairment loss of $0.9 million on those assets. These losses are recorded in the “Other expense” section of the Consolidated Statements of Operations during the year ended December 31, 2015. The Company reviews property and equipment for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or the fair value, less the costs to sell, and are no longer depreciated. Approximately $6.4 million were classified as held for sale on the Company's Consolidated Balance Sheet at December 31, 2016. During the year ended December 31, 2017, approximately $5.4 million of these assets were sold for cash of $4.5 million . The difference of $0.9 million is classified as a loss on the sale of assets on the Consolidated Statements of Operations. The remaining assets held for sale of $1.0 million was classified as a total loss as a result of Hurricane Harvey. Insurance claims of approximately $0.9 million were received in the fourth quarter of 2017. The difference of $0.1 million is classified as a loss on disposal of assets on the Consolidated Statements of Operations. No assets remained as held for sale on the Company's Consolidated Balance Sheet at December 31, 2017.

Inventory

Inventory	12 Months Ended
	Dec. 31, 2017
Inventory Disclosure [Abstract]
Inventory	Inventory Current inventory at December 31, 2017 and December 31, 2016 , of $4.4 million and $5.4 million , respectively, consisted primarily of spare parts and small equipment held for use in the ordinary course of business. Non-current inventory at December 31, 2017 and December 31, 2016 totaled $4.9 million and $4.0 million , respectively, and consisted primarily of spare engine components or items which require longer lead times for sourcing or fabrication for certain of the Company's assets to reduce equipment downtime.

Fair Value

Fair Value	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Fair Value	Fair Value Recurring Fair Value Measurements The fair value of financial instruments is the amount at which the instrument could be exchanged in a current transaction between willing parties. Due to their short-term nature, the Company believes that the carrying value of its accounts receivable, other current assets, accounts payable and other current liabilities approximate their fair values. The Company classifies financial assets and liabilities into the following three levels based on the inputs used to measure fair value in the order of priority indicated: • Level 1- fair values are based on observable inputs such as quoted prices in active markets for identical assets or liabilities; • Level 2 - fair values are based on pricing inputs other than quoted prices in active markets for identical assets and liabilities and are either directly or indirectly observable as of the measurement date; and • Level 3- fair values are based on unobservable inputs in which little or no market data exists. Financial assets and liabilities are classified in their entirety based on the lowest level of input that is significant to the fair value measurement. The Company's assessment of the significance of a particular input to the fair value requires judgment and may affect the placement of assets and liabilities within the fair value hierarchy levels. The following table sets forth by level within the fair value hierarchy the Company's recurring financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2017 and December 31, 2016 : Fair Value Measurements Carrying Value Level 1 Level 2 Level 3 December 31, 2017 Assets: Cash surrender value of life insurance policy $ 1,712 — 1,712 — Liabilities: Derivatives $ 38 — 38 — December 31, 2016 Assets: Cash surrender value of life insurance policy $ 1,188 — 1,188 — Liabilities: Derivatives $ 447 — 447 — The Company's derivatives, which are comprised of interest rate swaps, are valued using a discounted cash flow analysis that incorporates observable market parameters, such as interest rate yield curves and credit risk adjustments, that are necessary to reflect the probability of default by us or the counterparty. These derivatives are classified as a Level 2 measurement within the fair value hierarchy. See Note 11 for additional information on the Company's derivative instrument. Our concrete segment has life insurance policies covering four employees with a combined face value of $11.1 million . The policies are invested in mutual funds and the fair value measurement of the cash surrender balance associated with these policies is determined using Level 2 inputs within the fair value hierarchy and will vary with investment performance. These assets are included in the "Other noncurrent" asset section in the Company's Consolidated Balance Sheets. Non-Recurring Fair Value Measurements The Company generally applies fair value valuation techniques on a non-recurring basis associated with (1) valuing assets and liabilities acquired in connection with business combinations and other transactions; (2) valuing potential impairment loss related to long-lived assets; and (3) valuing potential impairment loss related to goodwill and indefinite-lived intangible assets. Other Fair Value Measurements The fair value of the Company's debt at December 31, 2017 and 2016 approximated its carrying value of $88.8 million and $104.6 million , respectively, as interest is based on current market interest rates for debt with similar risk and maturity. If the Company's debt was measured at fair value, it would have been classified as Level 2 in the fair value hierarchy.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill The table below summarizes changes in goodwill recorded by the Company during the periods ended December 31, 2017 and 2016 : December 31, December 31, Beginning balance, January 1 $ 66,351 $ 65,982 Additions 3,132 369 Ending balance $ 69,483 $ 66,351 At December 31, 2017 , goodwill totaled $69.5 million , of which $33.8 million relates to the marine segment and $35.7 million relates to the concrete segment. Additions to goodwill in 2017 were attributable to the acquisition of TBC. The additions above represent goodwill calculated for the acquisition at the date of closing, plus the working capital adjustment which was all attributable to goodwill. Additions to goodwill in 2016 were attributable to the acquisition of TAS (See Note 3 ). As discussed previously in Note 2 , goodwill is reviewed at a reporting unit level for impairment annually as of October 31 or whenever circumstances arise that indicate a possible impairment might exist. Test of impairment requires a two-step process to be performed to analyze whether or not goodwill has been impaired. Step one of the October 31, 2017 goodwill impairment test resulted in no indication of impairment for either reporting unit, and no events have occurred since that date that would require an interim impairment test. The discount rate used in testing goodwill for impairment for the marine segment was 35.0% , and the fair value of the reporting unit exceeded carrying value by 12.8% . The fair value of the marine reporting unit was $212.0 million , and the carrying value was $188.0 million . The discount rate used in testing goodwill for impairment for the concrete reporting unit was 30.0% , and the fair value of the reporting unit exceeded carrying value by 13.7% . The fair value of the concrete reporting unit was $153.0 million , and the carrying value was $134.5 million . Intangible assets The tables below present the activity and amortizations of finite-lived intangible assets: December 31, December 31, Intangible assets, January 1 $ 34,362 $ 34,362 Additions 878 — Total intangible assets, end of year 35,240 34,362 Accumulated amortization, January 1 $ (19,220 ) $ (11,933 ) Current year amortization (4,736 ) (7,287 ) Total accumulated amortization (23,956 ) (19,220 ) Net intangible assets, end of year $ 11,284 $ 15,142 Finite-lived intangible assets were acquired as part of the purchase of TBC, which included contractual backlog and customer relationships. Contractual backlog was valued at approximately $0.1 million and was amortized over seven months in 2017. Customer relationships were valued at approximately $0.7 million and will be amortized over seven years. Both of these assets will be amortized using an accelerated method based on the pattern in which the economic benefits of the assets are consumed. For the year ended December 31, 2017 , $4.7 million of amortization expense was recognized for these assets. In 2017 and 2016, the Company evaluated the useful lives of these finite-lived intangible assets and no change was needed. Future expense remaining of approximately $11.3 million will be amortized as follows: 2018 $ 3,389 2019 2,640 2020 2,069 2021 1,521 2022 1,239 Thereafter 426 $ 11,284 Additionally, the Company has one indefinite-lived intangible asset, a trade name, which is tested for impairment annually on October 31, or whenever events or circumstances indicate that the carrying amount of the trade name may not be recoverable. Impairment is calculated as the excess of the trade name’s carrying value over its fair value. The fair value of the trade name is determined using the relief from royalty method, a variation of the income approach. This method assumes that if a company owns intellectual property it does not have to "rent" the asset and is, therefore, "relieved" from paying a royalty. Once a supportable royalty rate is determined, the rate is then applied to the projected revenues over the expected remaining life of the intangible assets to estimate the royalty savings. This approach is dependent on a number of factors, including estimates of future growth and trends, royalty rates, discount rates and other variables. The impairment test concluded that the fair value of the trade name was $9.2 million , and the carrying value was $6.9 million , therefore no impairment was recorded.

Accrued Liabilities

Accrued Liabilities	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Accrued Liabilities	Accrued Liabilities Accrued liabilities at December 31, 2017 and 2016 consisted of the following: 2017 2016 Accrued salaries, wages and benefits $ 9,632 $ 10,818 Accrual for insurance liabilities 5,233 5,223 Property taxes 513 1,615 Sales taxes 1,836 1,722 Interest 46 19 Other accrued expenses 613 549 $ 17,873 $ 19,946

Long-term Debt and Line of Cred

Long-term Debt and Line of Credit	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Long-term Debt and Line of Credit	Long-term Debt and Line of Credit The Company entered into a syndicated credit agreement (the "Credit Agreement") on August 5, 2015 with Regions Bank, as administrative agent and collateral agent, and the following co-syndication agents: Bank of America, N.A., BOKF, NA dba Bank of Texas, Branch Banking & Trust Company, Frost Bank, Bank Midwest, a division of NBH Bank, N.A., IBERIABANK, KeyBank NA, Trustmark National Bank, and First Tennessee Bank NA. The primary purpose of the Credit Agreement was to finance the acquisition of TAS, to provide a revolving line of credit and to provide financing to extinguish all prior indebtedness with Wells Fargo Bank, National Associates, as administrative agent, and Wells Fargo Securities, LLC. The Credit Agreement, which may be amended from time to time, provides for borrowings under a revolving line of credit and swingline loans with a commitment amount of $50.0 million and a term loan with a commitment amount of $135.0 million (together, the “Credit Facility”). The Credit Facility is guaranteed by the subsidiaries of the Company, secured by the assets of the Company, including stock held in its subsidiaries, and may be used to finance general corporate and working capital purposes, to finance capital expenditures, to refinance existing indebtedness, to finance permitted acquisitions and associated fees, and to pay for all related expenses to the Credit Facility. Interest is due and is computed based on the designation of the loan, with the option of a Base Rate Loan (the base rate plus the Applicable Margin), or an Adjusted LIBOR Rate Loan (the adjusted LIBOR rate plus the Applicable Margin). Interest is due on the last day of each quarter end for Base Rate Loans and at the end of the LIBOR rate period for Adjusted LIBOR Rate Loans. The rate for all loans, at the time of loan origination was 4.75% . Principal balances drawn under the Credit Facility may be prepaid at any time, in whole or in part, without premium or penalty. Amounts repaid under the revolving line of credit may be re-borrowed. The Credit Facility matures on August 5, 2020. Total debt issuance costs, which included underwriter fees, legal fees and syndication fees were approximately $4.5 million . During the first quarter of 2016, the Company executed the First Amendment of the Credit Agreement and additional costs were incurred of approximately $0.5 million . During the second quarter of 2017, the Company executed the Second Amendment of the Credit Agreement and during the third quarter of 2017, the Company executed the Third Amendment of the Credit Agreement. Additional costs were incurred of approximately $0.2 million and $0.6 million , respectively. During the first quarter of 2016, the Company adopted ASU 2015-03, Interest - Imputation of Interest, Simplifying the Presentation of Debt Issuance Costs . Upon adoption of this guidance, debt issuance costs are now presented as a direct deduction from the carrying amount of the debt liability, of which $0.7 million was allocated to current debt and $2.1 million was allocated to long-term debt as of December 31, 2017 . As of December 31, 2016, $0.6 million was allocated to current debt and $2.7 million was allocated to long-term debt. The debt issuance costs are amortized using the effective interest rate method over the duration of the loans. The weighted average interest rate for the Credit Facility as of December 31, 2017 was 3.80% . The Company's obligations under debt arrangements consisted of the following: December 31, 2017 December 31, 2016 Principal Debt Issuance Costs (1) Total Principal Debt Issuance Costs (1) Total Revolving line of credit $ 10,000 $ (317 ) $ 9,683 $ 8,000 $ (252 ) $ 7,748 Term loan - current 13,500 (427 ) 13,073 11,813 (373 ) 11,440 Total current debt 23,500 (744 ) 22,756 19,813 (625 ) 19,188 Term loan - long-term 65,250 (2,065 ) 63,185 84,750 (2,673 ) 82,077 Total debt $ 88,750 $ (2,809 ) $ 85,941 $ 104,563 $ (3,298 ) $ 101,265 (1) Total debt issuance costs, include underwriter fees, legal fees, syndication fees, and fees related to the execution of the First, Second, and Third Amendments to the Credit Agreement as previously discussed. Provisions of the revolving line of credit and accordion T he Company has a maximum borrowing availability under the revolving line of credit and swingline loans (as defined in the Credit Agreement) of $50.0 million . The letter of credit sublimit is equal to the lesser of $20.0 million and the aggregate unused amount of the revolving commitments then in effect. The swingline sublimit is equal to the lesser of $5.0 million and the aggregate unused amount of the revolving commitments then in effect. Revolving loans may be designated as Base Rate Loan or Adjusted LIBOR Rate Loans, at the Company’s request, and must be made in an aggregate minimum amount of $1.0 million and integral multiples of $250,000 in excess of that amount. Swingline loans must be made in an aggregate minimum amount of $250,000 and integral multiples of $50,000 in excess of that amount. The Company may convert, change, or modify such designations from time to time. The Company is subject to a commitment fee for the unused portion of the maximum available to borrow under the revolving line of credit. The commitment fee, which is due quarterly in arrears, is equal to the Applicable Margin of the actual daily amount by which the Aggregate Revolving Commitments exceeds the Total Revolving Outstanding. The revolving line of credit termination date is the earlier of the Credit Facility termination date, August 5, 2020, or the date the outstanding balance is permanently reduced to zero. The Company has the intent and ability to repay the amounts outstanding on the revolving credit facility within one year, therefore, any outstanding balance as of December 31, 2017 and 2016 has been classified as current. As of December 31, 2017 , the outstanding balance on the revolving line of credit was $10.0 million and was designated as an Adjusted LIBOR Rate Loan at a rate of 5.0% . There were also $0.7 million in outstanding letters of credit as of December 31, 2017 , which reduced the maximum borrowing availability on the revolving line of credit to $39.3 million as of December 31, 2017 . During 2017, the Company drew down $72.0 million and made payments of $70.0 million on the revolving line of credit. Provisions of the term loan The original principal amount of $135.0 million for the term loan commitment is paid off in quarterly installment payments (as stated in the Credit Agreement). At December 31, 2017 , the outstanding term loan component of the Credit Facility totaled $78.8 million and was secured by specific assets of the Company. The table below outlines the total remaining payment amounts annually for the term loan through maturity of the Credit Facility: 2018 13,500 2019 15,188 2020 50,062 $ 78,750 The Company made the scheduled quarterly principal payments of $ 11.8 million and additional payments of $6.0 million during 2017 , which reduced the outstanding principal balance to $78.8 million at December 31, 2017 . The current portion of debt is $13.5 million and the non-current portion is $65.3 million . As of December 31, 2017 , the term loan was designated as an Adjusted LIBOR Rate Loan with an interest rate of 5.13 %. Financial covenants Restrictive financial covenants under the Credit Facility include: • A consolidated Fixed Charge Coverage Ratio as of the end of any fiscal quarter to not be less than 1.25 to 1.00. • A consolidated Leverage Ratio to not exceed the following during each noted period: -Closing Date through and including December 31, 2015, to not exceed 3.25 to 1.00; -Fiscal Quarter Ending March 31, 2016, to not exceed 4.00 to 1.00; -Fiscal Quarter Ending June 30, 2016, to not exceed 3.75 to 1.00; -Fiscal Quarter Ending September 30, 2016, to not exceed 3.25 to 1.00. -Fiscal Quarter Ending December 31, 2016, to not exceed 3.00 to 1.00; -Fiscal Quarter Ending March 31, 2017, to not exceed 2.75 to 1.00; -Fiscal Quarter Ending June 30, 2017, to not exceed 2.75 to 1.00; -Fiscal Quarter Ending September 30, 2017, to not exceed 3.00 to 1.00; -Fiscal Quarter Ending December 31, 2017 and each Fiscal Quarter Thereafter, to not exceed 3.00 to 1.00. As of December 31, 2017 , the Company was in compliance with all financial covenants. In addition, the Credit Facility contains events of default that are usual and customary for similar arrangements, including non-payment of principal, interest or fees; breaches of representations and warranties that are not timely cured; violation of covenants; bankruptcy and insolvency events; and events constituting a change of control. The Company expects to meet its future internal liquidity and working capital needs, and maintain or replace its equipment fleet through capital expenditure purchases and major repairs, from funds generated by its operating activities for at least the next 12 months. The Company believes that its cash position and available borrowings together with cash flow from its operations is adequate for general business requirements and to service its debt. Derivative Financial Instruments On September 16, 2015 , the Company entered into a series of receive-variable, pay-fixed interest rate swaps to hedge the variability in the interest payments on 50% of the aggregate principal amount of the Regions Term Loan outstanding, beginning with a notional amount of $67.5 million . There are a total of five sequential interest rate swaps to achieve the hedged position and each year on August 31, with the exception of the final swap, the existing interest rate swap is scheduled to expire and will be immediately replaced with a new interest rate swap until the expiration of the final swap on July 31, 2020. At inception, these interest rate swaps were designated as a cash flow hedge for hedge accounting, and as such, the effective portion of unrealized changes in market value are recorded in accumulated other comprehensive income (loss) and reclassified into earnings during the period in which the hedged forecasted transaction affects earnings. Gains and losses from hedge ineffectiveness are recognized in current earnings. The change in fair market value of the swaps as of December 31, 2017 is less than $0.1 million , which is reflected in the balance sheet as a liability. The fair market value of the swaps as of December 31, 2017 is less than $0.1 million . See Note 8 for more information regarding the fair value of the Company's derivative instruments.

Purchase of Common Shares

Purchase of Common Shares	12 Months Ended
	Dec. 31, 2017
Equity [Abstract]
Purchase of Common Shares	Purchase of Common Shares In October 2014, the Board of Directors of the Company approved a common share repurchase program that authorized the repurchase of up to $40.0 million in open market value. The shares may be repurchased over time, depending on market conditions, the market price of the Company's common shares, the Company's capital levels, the Company's capital needs, securities laws and limitations and other considerations. The share repurchase program is expected to expire five years from the date the program was approved. As of December 31, 2015, the Company repurchased 350,000 shares at an average price of $8.83 . The Company did not repurchase any shares during 2016 or 2017.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes On December 22, 2017, the Act was enacted and signed into law. The Act makes broad and complex changes to the U.S. tax code that significantly affected the Company's income tax rate in 2017. The Act, among other things, reduces the U.S. federal corporate income tax rate from 35% to 21% ; limits the use of foreign tax credits to reduce U.S. income tax liability; eliminates the corporate AMT and changes how existing AMT credits can be realized; allows immediate expensing for qualified assets; creates a new limitation on deductible interest expense; repeals the domestic production activities deduction; and limits the deductibility of certain executive compensation and other deductions. ASC 740 requires a company to record the effects of a tax law change in the period of enactment. SAB 118 has provided guidance for companies that have not completed their accounting for the income tax effect of the Act in the period of enactment, allowing for a measurement period of up to one year after the enactment date in order to finalize the recording of the related tax impacts. As of December 31, 2017, the Company has made a reasonable estimate of the impact of the Act and recorded a net tax benefit of $5.9 million , or $0.21 per share, as part of its income tax benefit for the year. Although the $5.9 million represents a reasonable estimate of the impact of the Act, it should be considered provisional. The impact of the Act may differ from this estimate due to additional guidance that may be issued, changes in assumptions made and the finalization of U.S. income tax positions with the filing of the Company's 2017 U.S. income tax return which will allow for the ability to conclude whether any further adjustments are necessary to its deferred tax assets and liabilities. Any adjustments to these provisional amounts will be reported as a component of income tax (benefit) expense in the reporting period in which any such adjustments are identified and no later than the fourth quarter of 2018. The Company will continue to analyze the Act in order to finalize any related impacts within the measurement period. The following table presents the components of our consolidated income tax (benefit) expense for the years ended December 31, 2017 , 2016 and 2015 : Current Deferred Total Year ended December 31, 2017 U.S. Federal (a) $ (780 ) $ (3,986 ) $ (4,766 ) State and local 550 $ (180 ) $ 370 Foreign (145 ) — (145 ) $ (375 ) $ (4,166 ) $ (4,541 ) Year ended December 31, 2016 U.S. Federal $ 35 $ (1,093 ) $ (1,058 ) State and local 511 1,519 2,030 Foreign 284 325 609 $ 830 $ 751 $ 1,581 Year ended December 31, 2015 U.S. Federal $ 3 $ (3,768 ) $ (3,765 ) State and local (60 ) 883 823 Foreign 423 — 423 $ 366 $ (2,885 ) $ (2,519 ) (a) Includes a $5.9 million net benefit recorded in the fourth quarter of 2017 resulting from the enactment of the Act on December 22, 2017. The Company’s income tax provision reconciles to the provision at the statutory U.S. federal income tax rate for each year ended December 31, as follows: 2017 2016 2015 Statutory amount (computed at 35%) $ (1,449 ) $ (714 ) $ (3,703 ) Re-measurement of deferred tax assets (a) (7,451 ) — — Valuation allowance on foreign tax credits (a) 1,514 — — State income tax, net of federal benefit 168 94 (709 ) Permanent differences, other 505 99 43 Permanent differences, incentive stock options 447 224 298 Valuation allowance, other (77 ) 1,769 1,552 Uncertain tax provision 1,614 — — Other 188 109 — Consolidated income tax provision $ (4,541 ) $ 1,581 $ (2,519 ) Consolidated effective tax rate 109.7 % (77.5 )% 23.8 % (a) Represents estimated impact recorded in the fourth quarter of 2017 resulting from the enactment of the Act on December 22, 2017. In the current year, the Company's effective tax rate differed from the statutory rate of 35% primarily due to the impact of the Act enacted on December 22, 2017. We recorded a net tax benefit of $5.9 million , or $0.21 per share, resulting from the re-measurement of the Company’s net deferred tax liabilities to reflect the new, lower U.S. corporate income tax rate of 21% , partially offset by the addition of a partial valuation allowance recorded against existing foreign tax credit carryforwards not expected to be utilized in future tax years. This net tax benefit was partially offset by the addition of an uncertain tax position reserve as well as tax expense for permanent differences associated with incentive stock options and meals and entertainment. Deferred Taxes The Company’s deferred tax assets and liabilities are as follows: December 31, 2017 December 31, 2016 Current Long- term (a) Current Long-term Assets related to: Accrued liabilities $ — $ 1,226 $ 2,322 $ — Intangible assets — 3,010 — 4,517 Net operating loss carryforward — 6,912 — 7,455 Valuation allowance — (3,942 ) — (3,321 ) Non-qualified stock options — 762 112 1,367 Foreign tax credits — 1,751 — 2,035 Valuation allowance on foreign tax credits — (1,514 ) — — AMT credits — — — 780 Other — 215 45 16 Total assets — 8,420 2,479 12,849 Liabilities related to: Depreciation and amortization — (15,788 ) — (25,326 ) Goodwill — (5,178 ) — (6,502 ) Deferred revenue on maintenance contracts — (597 ) (429 ) — Other — (100 ) (37 ) (21 ) Total liabilities — (21,663 ) (466 ) (31,849 ) Net deferred (liabilities) assets $ — $ (13,243 ) $ 2,013 $ (19,000 ) (a) Components of our deferred tax assets and liabilities at December 31, 2017 after taking into account the estimated impact of the Act and related items. As reported in the Consolidated Balance Sheets: December 31, 2017 December 31, 2016 Net current deferred tax assets — 2,013 Net non-current deferred tax liabilities (13,243 ) (19,000 ) Total net deferred tax liabilities: $ (13,243 ) $ (16,987 ) In the quarter ended March 31, 2017, the Company adopted ASU 2015-17, Balance Sheet Classification of Deferred Taxes . Previously, U.S. GAAP required an entity to separate deferred income tax liabilities and assets into current and non-current amounts in a classified statement of financial position. The amendments in this update require that deferred tax liabilities and assets be classified as non-current in a classified statement of financial position. The Company elected to adopt this guidance prospectively and as such $2.0 million of deferred tax assets as of December 31, 2016 appears on the balance sheet as current. Additionally, in the quarter ended March 31, 2017, the Company adopted ASU 2016-09, Improvements to Employee-Based Payment Accounting . As part of this adoption, certain federal net operating losses ("NOLs") that were previously classified as off-balance sheet are now being recognized as deferred tax assets through an adjustment to opening retained earnings. The Company chose to prospectively adopt this guidance during the first quarter of 2017 and as such the balance sheet includes an adjustment of approximately $0.7 million as an addition to "Retained earnings" and a reduction to the "Deferred income taxes" line items on the Consolidated Balance Sheet in order to true-up the tax effected portion of the NOLs mentioned above. Due to the prospective adoption, no prior year adjustments were made. The Company assessed the realizability of its deferred tax assets at December 31, 2017 and 2016, and considered whether it was more likely than not that some portion or all of the deferred tax assets will not be realized. The realization of deferred tax assets depends upon the generation of future taxable income, which includes the reversal of deferred tax liabilities related to depreciation, during the periods in which these temporary differences become deductible. The Company has a tax effected NOLs as of December 31, 2017 of $5.7 million for state income tax reporting purposes due to the cumulative losses sustained in various states. The Company believes it will be able to partially utilize these NOLs against future income primarily with reversing of temporary differences attributable to depreciation, due to expiration dates well into the future. However, the Company has determined that a portion of the NOLs related to certain jurisdictions will more likely than not be able to be fully utilized. Therefore, a valuation allowance of $3.9 million exists for this portion of the NOL. For federal tax purposes, the Company has utilized its ability to carry losses back prior to 2017 . Approximately $1.2 million remains as a tax effected federal net operating loss carryforward, which the Company believes it will be able to utilize before expiration. As of December 31, 2017 the Company had approximately $0.7 million of AMT available that do not expire. As part of the Act, any remaining AMT after 2017 will be refunded to the Company beginning in 2018 through 2021, and therefore, the Company reclassified the existing balance from a deferred tax asset to an other non-current asset as of December 31, 2017. Uncertain Tax Benefits The Company and its subsidiaries file consolidated federal income tax returns in the United States and also file in various states. With few exceptions, the Company remains subject to federal and state income tax examinations for the years of 2012, 2013, 2014, 2015, and 2016. As of December 31, 2017, the Company had approximately $1.6 million of total unrecognized tax benefits as a result of uncertain tax positions. As of December 31, 2016 and 2015, the Company had not recorded unrecognized tax benefits for any uncertain tax positions. The Company does not expect that unrecognized tax benefits as of December 31, 2017 for certain federal income tax matters will significantly change over the next 12 months. The final outcome of these uncertain tax positions is not yet determinable. Our uncertain tax benefits, if recognized, would affect the Company's effective tax rate. The change in the total gross unrecognized tax benefits and prior year audit resolutions of the Company during the year ended December 31, 2017 is reconciled in the table below: 2017 Balances at beginning of the year $ — Additions based on tax position related to current year — Additions based on tax positions related to prior years 1,614 Reductions based on tax positions related to current year — Reductions based on tax positions related to prior years — Settlements with tax authorities — Lapse of statute of limitations — Balance at the end of year $ 1,614 The Company’s policy is to recognize interest and penalties related to any unrecognized tax liabilities as additional tax expense. No interest or penalties have been accrued at December 31, 2017, 2016 and 2015. The Company believes it has appropriate and adequate support for the income tax positions taken and to be taken on its tax returns and that its accruals for tax liabilities are adequate for all open years based on an assessment of many factors including past experience and interpretations of tax law applied to the facts of each matter. Although the Company believes its recorded assets and liabilities are reasonable, tax regulations are subject to interpretation and tax litigation is inherently uncertain; therefore the Company’s assessments can involve both a series of complex judgments about future events and rely heavily on estimates and assumptions. Although the Company believes that the estimates and assumptions supporting its assessments are reasonable, the final determination of tax audit settlements and any related litigation could be materially different from that which is reflected in historical income tax provisions and recorded assets and liabilities. If the Company were to settle an audit or a matter under litigation, it could have a material effect on the income tax provision, net income, or cash flows in the period or periods for which that determination is made. Any accruals for tax contingencies are provided for in accordance with U.S. GAAP . The Company does not believe that its tax positions will significantly change due to any settlement and/or expiration of statutes of limitations prior to December 31, 2018 .

Earnings (Loss) Per Share

Earnings (Loss) Per Share	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Earnings (Loss) Per Share	(Loss) Per Share Basic earnings (loss) per share are based on the weighted average number of common shares outstanding during each period. Diluted earnings per share are based on the weighted average number of common shares outstanding and the effect of all dilutive common stock equivalents during each period. The exercise price for certain stock options awarded by the Company exceeds the average market price of the Company's common stock. Such stock options are anti-dilutive and are not included in the computation of earnings (loss) per share. For the years ended December 31, 2017 , 2016 and 2015 , the Company had 2,274,908 , 2,381,926 , and 2,043,375 , securities, respectively, that were potentially dilutive in future earnings per share calculations. Such dilution will be dependent on the excess of the market price of our stock over the exercise price and other components of the treasury stock method. The following table reconciles the denominators used in the computations of both basic and diluted earnings (loss) per share: Year ended December 31, 2017 2016 2015 Basic: Weighted average shares outstanding 28,029,936 27,536,967 27,366,528 Diluted: Total basic weighted average shares outstanding 28,029,936 27,536,967 27,366,528 Effect of dilutive securities: Common stock options 324,344 — — Total weighted average shares outstanding assuming dilution 28,354,280 27,536,967 27,366,528 Anti-dilutive stock options — — — Shares of common stock issued from the exercise of stock options 229,551 13,850 3,970

Stock-Based Compensation

Stock-Based Compensation	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Stock-Based Compensation	Stock-Based Compensation The Compensation Committee of the Company’s Board of Directors is responsible for the administration of the Company’s stock incentive plans, which include the balance of shares remaining under the 2011 Long Term Incentive Plan (the "2011 LTIP") and 2017 Long Term Incentive Plan (the "2017 LTIP"), which was approved by shareholders in May 2017 and authorized the maximum aggregate number of shares to be issued of 2,400,000 . In general, the Company's 2017 LTIP provides for grants of restricted stock and stock options to be issued with a per-share price equal to the fair market value of a share of common stock on the date of grant. Option terms are specified at each grant date, but are generally are 10 years from the date of issuance. Options generally vest over a three year period. Restricted Stock The following table summarizes the restricted stock activity under the Company's equity incentive plans : Number of Shares Weighted Average Fair Value Per Share Nonvested at January 1, 2015 235,863 $ 8.63 Granted 38,660 $ 5.82 Vested (134,545 ) $ 6.84 Forfeited/repurchased shares (19,824 ) $ 11.35 Nonvested at December 31, 2015 120,154 $ 9.28 Granted 407,002 $ 4.96 Vested (147,259 ) $ 6.62 Forfeited/repurchased shares (7,591 ) $ 7.08 Nonvested at December 31, 2016 372,306 $ 5.66 Granted 345,913 $ 7.22 Vested (225,406 ) $ 7.25 Forfeited/repurchased shares (120,353 ) $ 6.08 Nonvested at December 31, 2017 372,460 $ 6.01 Independent directors receive equity compensation in the form of grants. In May 2017, the Company's independent directors each received equity compensation grants of 12,465 shares, with a fair value of $7.22 per share and in May 2016, the Company's independent directors each received equity compensation grants of 14,170 shares, with a fair value of $4.94 per share. Additionally, in 2017, certain officers and executives of the Company were awarded 213,643 shares with a vesting period of three years and a weighted average fair value of $7.22 per share and in 2016, certain officers and executives of the Company were awarded 267,175 shares with a vesting period of three years and a weighted average fair value of $4.96 per share. No shares were granted to independent directors, officers or executives of the Company during 2015, except for the chief operating officer who joined the Company in September 2015. Upon execution of his employment agreement, he was awarded 38,660 shares, with a vesting period of three years and a fair value of $5.82 per share. Performance Stock In May 2017, the Company awarded certain executives 69,945 shares of performance based stock, which vest based on the achievement of an objective return on invested capital measured over a two -year performance period covering the 2018 and 2019 fiscal years. The fair value on the date of grant was $7.22 per share. In May 2016, the Company awarded certain executives 68,977 shares of performance based stock, which vest based on the achievement of an objective return on invested capital measured over a two -year performance period covering the 2017 and 2018 fiscal years. The fair value on the date of the grant was $4.94 per share. Stock Options The following table summarizes the stock option activity under the Company's equity incentive plans: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Contractual Life (Years) Aggregate Intrinsic Value Outstanding at January 1, 2015 2,056,898 $ 9.86 Granted 143,862 $ 5.82 Exercised (3,970 ) $ 6.00 Forfeited (46,890 ) $ 11.72 Outstanding at December 31, 2015 2,149,900 $ 9.56 Granted 587,862 $ 4.98 Exercised (13,850 ) $ 4.86 Forfeited (374,466 ) $ 9.89 Outstanding at December 31, 2016 2,349,446 $ 8.39 Granted 425,204 $ 7.22 Exercised (229,551 ) $ 5.75 Forfeited (633,978 ) $ 10.36 Outstanding at December 31, 2017 1,911,121 $ 7.79 Vested and expected to vest at December 31, 2017 2,024,130 $ 7.69 5.26 $ 2,872 Exercisable at December 31, 2017 1,462,481 $ 8.18 3.82 $ 2,054 The Company calculates the fair value of each option on the date of grant using the Black-Scholes pricing model and the following weighted-average assumptions in each year: 2017 2016 2015 Weighted average grant-date fair value of options granted $ 7.22 $ 4.97 $ 5.82 Risk-free interest rate 1.46 % 1.06 % 0.97 % Expected volatility 48 % 49 % 38 % Expected term of options (in years) 3.0 3.0 3.0 Dividend yield — % — % — % The risk-free interest rate is based on interest rates on U.S. Treasury zero-coupon issues that match the contractual terms of the stock option grants. The expected term represents the period in which the Company’s equity awards are expected to be outstanding, which for the years presented is based on the exercise history. For years ended December 31, 2017 , 2016 and 2015 , compensation expense related to stock based awards outstanding for the periods was $2.3 million , respectively. The Company applies a 3.2% and 5.5% forfeiture rate, which gets compounded over the vesting terms of the individual award, to its restricted stock and option grants, respectively, based on historical analysis. During the year ended December 31, 2017 , certain officers and executives of the Company were awarded 425,204 options with a vesting period of three years and a weighted average fair value of $7.22 per share, and for the year ended December 31, 2016, certain officers and executives were awarded 587,862 options with a vesting period of three years and a fair value of $4.98 per share. No options were awarded to officers or executives of the Company as of the year ended December 31, 2015, except for the chief operating officer who joined the Company in September 2015. Upon execution of his employment agreement, he was granted 143,862 shares, with a vesting period of three years and a fair value of $5.82 per share. In the year ended December 31, 2017 , the Company received proceeds of approximately $1.3 million upon the exercise of 229,551 options. In the year ended December 31, 2016 , proceeds of $67,000 upon the exercise of 13,850 options and in the year ended December 31, 2015 , 3,970 options were exercised, generating proceeds of $28,000 . As of December 31, 2017 , total unrecognized compensation expense related to unvested stock and options was approximately $2.9 million, which is expected to be recognized over a period of approximately 2.0 years. 2017 2016 2015 Total intrinsic value of options exercised $ 706 $ 53 $ 17 Total fair value of shares vested $ 855 $ 986 $ 1,226

Employee Benefits

Employee Benefits	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Employee Benefits	Employee Benefits All of the Company's marine segment employees except the Associate Divers, the Associate Tugmasters, and union employees in the Pacific Northwest, are eligible to participate in the Company’s 401(k) Retirement Plan after completing six months of service. Each participant may contribute between 1% and 80% of eligible compensation on a pre-tax basis, up to the annual IRS limit. The Company matches 100% on the first 2% of eligible compensation contributed to the Plan and 50% on the next 2% of eligible compensation contributed to the Plan. Participants’ contributions are fully vested at all times. Employer matching contributions vest over a four -year period. At its discretion, the Company may make additional matching and profit-sharing contributions. During the years ended December 31, 2017 , 2016 and 2015 the Company contributed $1.4 million to the Plan, respectively. All of the Company's concrete segment employees except Leads, Helpers, Laborers, Finishers, Formsetters, Carpenters, Rodbusters, Patchmen, Equipment Operators, Field Engineering Trainees and certain Highly Compensated Employees are eligible to participate in the AGC Southwest Chapters 401(k) Retirement Plan, a multiple employer plan, after completing three months of service. Each participant may contribute up to the annual IRS limit. The Company matches 50% on the first 6% of eligible compensation contributed to the Plan. Participants’ contributions are fully vested at all times. Employer matching contributions vest over a five -year period. At its discretion, the Company may make additional matching and profit-sharing contributions. During the year ended December 31, 2017 , 2016 and 2015, the Company contributed $0.4 million , $0.2 million and $0.1 million , respectively. The Company's marine segment contributes to several multi-employer defined pension plans under the terms of collective-bargaining agreements that cover its union-represented employees. Risks of participating in these multi-employer plans are different from single-employer plans in the following aspects: • Assets contributed to the multi-employer plan by one employer may be used to provide benefits to employees of other participating employers; • If a participating employer stops contributing to the plan, the unfunded obligations of the plan may be borne by the remaining participating employers; and • If the Company chooses to stop participating in its multi-employer plans, it may be required to pay a withdrawal liability based on the underfunded status of the plan. Currently, the Company's concrete segment does not have union represented employees and, thus, does not participate under the above-mentioned defined pension plans, or any other plans, that cover union-represented employees. The following table presents the Company's participation in these plans: Pension Protection Act ("PPA") Certified Zone Status (1) FIP/RP Status Contributions Expiration of Collective Bargaining Agreement Employer Identification Number Surcharge Imposed Pension Trust Fund 2017 2016 P/I (2) 2017 2016 2015 International Union of Operating Engineers - Employers Construction Industry Retirement Plan - Local 302 and 612 Trust Funds 91-6028571 Green Green N/A $ 1,974 $ 2,158 $ 1,518 — 2018 Associated General Contractors of Washington Carpenter, Piledrivers, and Millwrights 91-6029051 91-6029049 Green Green N/A $ 693 $ 938 $ 748 — 2018 Alaska Carpenters Trust Fund 92-0120866 Green Green N/A $ 396 $ 889 $ 807 — 2020 Alaska Laborers Trust Fund 91-6028298 Yellow Yellow P $ 218 $ 126 $ 110 — 2017 (1) The most recent PPA zone status available in 2017 and 2016 is for the plan's year end during 2016 and 2015, respectively. Zone status is based on information received from the plan and is indicative of the plans funding status. Among other factors, plans in the red zone are generally less than 65 percent funded, plans in the orange zone are less than 80 percent funded and have an Accumulated Funding Deficiency in the current year or projected into the next six years, plans in the yellow zone are less than 80 percent funded, and plans in the green zone are at least 80 percent funded. (2) The FIP/RP Status P/I column indicates plans for which a financial improvement plan ("FIP") or a rehabilitation plan ("RP") is either pending ("P"), or implemented ("I"). There are currently no plans to withdraw from any of the multi-employer plans in which the Company participates.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	Commitments and Contingencies Operating Leases In July 2005, the Company executed a sale-leaseback transaction in which it sold an office building for $2.1 million and entered into a ten year lease agreement. The sale of the office building resulted in a gain of $562,000 which has been deferred and amortized over the life of the lease. The Company recognized approximately $8,000 for the year ending 2015. Scheduled increases in monthly rent are included in the lease agreement. Rent expense under this agreement was approximately $85,000 for the year ending December 31, 2015. The Company, at its option, can extend the lease for two additional five -year terms. However, the Company opted not to renew the lease and it expired on July 1, 2015. In 2005, the Company entered into a lease agreement for vehicles under a continuing operating lease agreement. Rental expense under this lease for the years ended December 31, 2017 , 2016 and 2015 was $0.7 million , $1.5 million , and $2.3 million , respectively. In 2016, the Company started transitioning its vehicle leases to a new lease agreement in an effort to update and expand its current fleet. The Company expects to fully transition all of its fleet vehicles to this new lease over the course of the next several years. Rental expense under this lease for the year ended December 31, 2017 , and 2016 was $1.7 million , and $1.0 million , respectively. There was no rental expense at the end of December 31, 2015. The Company leases its corporate office in Houston, Texas under a lease with an initial term of nine years. In addition, the Company leases other facilities, including office space and yard facilities, under terms that range from one to five years. The Company also leases short-term field office space at its various construction sites for the duration of the projects. Future minimum lease payments under non-cancelable operating leases as of December 31, 2017 are as follows: Amount Year ended December 31, 2018 $ 7,371 2019 6,560 2020 5,364 2021 3,247 2022 1,824 Thereafter 12,947 $ 37,313 Litigation From time to time the Company is a party to various lawsuits, claims and other legal proceedings that arise in the ordinary course of business. These actions typically seek, among other things, compensation for alleged personal injury, breach of contract, property damage, punitive damages, civil penalties or other losses, or injunctive or declaratory relief. With respect to such lawsuits, the Company accrues reserves when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. The Company does not believe any other proceedings, individually or in the aggregate, would be expected to have a material adverse effect on results of operations, cash flows or financial condition.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Segment Reporting	Segment Information The Company currently operates in two reportable segments: marine and concrete. The Company's financial reporting systems present various data for management to run the business, including profit and loss statements prepared according to the segments presented. Management uses operating income to evaluate performance between the two segments. Segment information for the periods presented is provided as follows: Year Ended December 31, 2017 Year Ended December 31, 2016 Marine Contract revenues $ 285,736 $ 284,632 Operating loss (18,406 ) (12,403 ) Depreciation and amortization expense (20,370 ) (21,398 ) Total assets $ 260,935 $ 279,362 Property, plant and equipment, net 128,421 143,425 Concrete Contract revenues $ 292,817 $ 293,604 Operating income 19,944 16,477 Depreciation and amortization expense (9,121 ) (12,764 ) Total assets $ 172,350 $ 168,314 Property, plant and equipment, net 17,857 14,657 There were no intersegment revenues between the Company's two reportable segments for the years ended December 31, 2017 and 2016. The marine segment had foreign revenues of $9.4 million and $7.4 million , respectively, for the years ended December 31, 2017 and 2016 . These revenues are derived from projects in the Caribbean Basin and Mexico and are paid in U.S. dollars. There was no foreign revenue for the concrete segment.

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2017
Related Party Transactions [Abstract]
Related Party Transactions	Related Party Transactions Upon the completion of the TAS acquisition, the Company entered into a lease arrangement with an entity in which an employee owns an interest. This lease is for office space and yard facilities used by the concrete segment. Annual lease expense was approximately $478,000 and $820,000 for the years ending December 31, 2017 and 2016 , respectively. Due to the resignation of this employee, these transactions ceased to be related party transactions as of July 31, 2017 and resulted in a lower annual lease expense for 2017 compared to 2016.

Selected Quarterly Financial Da

Selected Quarterly Financial Data	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Selected Quarterly Financial Data	Selected Quarterly Financial Data The following tables set forth selected unaudited financial information for the eight quarters in the two-year period ended December 31, 2017 . This information has been prepared on the same basis as the audited financial statements and, in the opinion of management, contains all adjustments necessary for a fair presentation. First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (in thousands, except per share data) 2017 Revenues $ 138,757 $ 137,420 $ 140,162 $ 162,214 $ 578,553 Gross profit 12,985 15,397 10,757 27,751 66,890 Operating (loss) income (1,482 ) (2,466 ) (5,354 ) 10,840 1,538 (Loss) income before income taxes (2,827 ) (3,917 ) (6,703 ) 9,306 (4,141 ) Net (loss) income (1,808 ) (2,293 ) (5,037 ) 9,538 400 (Loss) earnings per share: Basic $ (0.07 ) $ (0.08 ) $ (0.18 ) $ 0.34 $ 0.01 Diluted $ (0.07 ) $ (0.08 ) $ (0.18 ) $ 0.34 $ 0.01 First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (in thousands, except per share data) 2016 Revenues $ 129,623 $ 140,301 $ 164,017 $ 144,295 $ 578,236 Gross profit 14,710 16,946 24,169 11,657 67,482 Operating (loss) income (455 ) 281 9,531 (5,283 ) 4,074 (Loss) income before income taxes (1,958 ) (1,310 ) 7,963 (6,734 ) (2,039 ) Net (loss) income (1,208 ) (808 ) 4,739 (6,343 ) (1 ) (3,620 ) (Loss) earnings per share: Basic $ (0.04 ) $ (0.03 ) $ 0.17 $ (0.23 ) $ (0.13 ) Diluted $ (0.04 ) $ (0.03 ) $ 0.17 $ (0.23 ) $ (0.13 ) (1) - Fourth quarter 2016 net loss includes $0.8 million of tax expense that represents an out of period adjustment associated with deferred taxes. Management evaluated the effect of the adjustment on the Company's financial statements based on SEC Staff Accounting Bulleting ("SAB") No. 99 and SAB 108 and concluded that it was immaterial to the current and prior year's financial statements.

Schedule II - Valuation and Qua

Schedule II - Valuation and Qualifying Accounts	12 Months Ended
	Dec. 31, 2017
Valuation and Qualifying Accounts [Abstract]
Schedule II - Valuation and Qualifying Accounts	SCHEDULE II - VALUATION AND QUALIFYING ACCOUNTS (Dollars in thousands) Description Balance at the Beginning of the Period Charged to Revenue, Cost or Expense Deduction Balance at the End of the Period Year ended December 31, 2015 Provision for Doubtful Accounts $ — $ 22 $ (22 ) $ — Year ended December 31, 2016 Provision for Doubtful Accounts $ — $ — $ — $ — Year ended December 31, 2017 Provision for Doubtful Accounts $ — $ — $ — $ —

Summary of Significant Accoun30

Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Basis of Presentation	Basis of Presentation These consolidated financial statements include the accounts of the parent company, Orion Group Holdings, Inc. and its wholly-owned subsidiaries and have been prepared in accordance with U.S. GAAP. All intercompany balances and transactions have been eliminated in consolidation.
Revenue Recognition	Revenue Recognition For financial statement purposes, the Company records revenue on construction contracts using the percentage-of-completion method, measured by the percentage of actual contract costs incurred to date to total estimated costs for each contract. This method is used because management considers contract costs incurred to be the best available measure of progress on these contracts. Contract revenue is derived from the original contract price adjusted for agreed upon change orders. Contract costs include all direct costs, such as material and labor, and those indirect costs incurred that are related to contract performance such as payroll taxes and insurance. General and administrative costs are charged to expense as incurred. Incentive fees, if available, are billed to the customer based on terms and conditions of the contract. Pending claims are recognized as an increase in contract revenue only when the collection is deemed probable and if the amount can be reasonably estimated for purposes of calculating total profit or loss on long-term contracts. The Company records revenue and the unbilled receivable for project claims to the extent of costs incurred and to the extent management believes related collection is probable and includes no profit on claims recorded. As of December 31, 2017 , the Company recognized claims of approximately $12.3 million with customers. The Company believes collection of these claims is probable, although the full amount of the recorded claims may not be collected. Changes in job performance, job conditions and estimated profitability, including those arising from final contract settlements, may result in revisions to costs and revenues and are recognized in the period in which the revisions are determined. Provisions for estimated losses on uncompleted contracts are made in the period in which such losses are determined, without regard to the percentage of completion. Revenue is recorded net of any sales taxes collected and paid on behalf of the customer, if applicable. The current asset “costs and estimated earnings in excess of billings on uncompleted contracts” represents revenues recognized in excess of amounts billed, which management believes will be billed and collected within one year of the completion of the contract. The liability “billings in excess of costs and estimated earnings on uncompleted contracts” represents billings in excess of revenues recognized. The Company’s projects are typically short in duration, and usually span a period of less than one year. Historically, the Company has not had cause to combine or segment contracts.
Classification of Current Assets and Liabilities	Classification of Current Assets and Liabilities The Company includes in current assets and liabilities amounts realizable and payable in the normal course of contract completion.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid investments with a maturity of three months or less when purchased to be cash equivalents. At times, cash held by financial institutions may exceed federally insured limits. The Company has not historically sustained losses on its cash balances in excess of federally insured limits. Cash equivalents at December 31, 2017 and 2016 consisted primarily of overnight bank deposits.
Risk Concentrations	Risk Concentrations Financial instruments that potentially subject the Company to concentrations of credit risk principally consist of accounts receivable. The Company depends on its ability to continue to obtain federal, state and local governmental contracts, and indirectly, on the amount of funding available to these agencies for new and current governmental projects. Therefore, a portion of the Company’s operations may be dependent upon the level and timing of government funding. Statutory mechanics liens provide the Company high priority in the event of lien foreclosures following financial difficulties of private owners, thus minimizing credit risk with private customers.
Accounts Receivable	Accounts Receivable Accounts receivable are stated at the historical carrying value, less allowances for doubtful accounts. The Company has significant investments in billed and unbilled receivables as of December 31, 2017 and 2016 . Billed receivables represent amounts billed upon the completion of small contracts and progress billings on large contracts in accordance with contract terms and milestone achievements. Unbilled receivables on contracts, which are included in costs in excess of billings, arise as revenues are recognized under the percentage-of-completion method. Unbilled amounts on contracts represent recoverable costs and accrued profits not yet billed. Revenue associated with these billings is recorded net of any sales tax, if applicable. Past due balances over 90 days and other higher risk amounts are reviewed individually for collectability. In establishing an allowance for doubtful accounts, the Company evaluates its contract receivables and costs in excess of billings and thoroughly reviews historical collection experience, the financial condition of its customers, billing disputes and other factors. The Company writes off uncollectible accounts receivable against the allowance for doubtful accounts if it is determined that the amounts will not be collected or if a settlement is reached for an amount that is less than the carrying value. As of December 31, 2017 and 2016 , the Company had not recorded an allowance for doubtful accounts. Balances billed to customers but not paid pursuant to retainage provisions in construction contracts generally become payable upon contract completion and acceptance by the owner. Retainage at December 31, 2017 totaled $39.2 million , of which $8.0 million is expected to be collected beyond 2018. Retainage at December 31, 2016 totaled $40.2 million . The Company negotiates change orders and claims with its customers. Unsuccessful negotiations of claims could result in a change to contract revenue that is less than amounts recorded, which could result in the recording of a loss. Successful claims negotiations could result in the recovery of previously recorded losses. Significant losses on receivables could adversely affect the Company’s financial position, results of operations and overall liquidity.
Advertising Costs	Advertising Costs The Company primarily obtains contracts through the open bid process, and therefore advertising costs are not a significant component of expense. Advertising costs are expensed as incurred.
Environmental Costs	Environmental Costs Costs related to environmental remediation are charged to expense. Other environmental costs are also charged to expense unless they increase the value of the property and/or provide future economic benefits, in which event the costs are capitalized. Environmental liabilities, if any, are recognized when the expenditure is considered probable and the amount can be reasonably estimated.
Fair Value Measurements	Fair Value Measurements The Company evaluates and presents certain amounts included in the accompanying consolidated financial statements at “fair value” in accordance with U.S. GAAP, which requires the Company to base its estimates on assumptions that market participants, in an orderly transaction, would use to price an asset or liability, and to establish a hierarchy that prioritizes the information used to determine fair value. Refer to Note 8 for more information regarding fair value determination. The Company generally applies fair value valuation techniques on a non-recurring basis associated with (1) valuing assets and liabilities acquired in connection with business combinations and other transactions; (2) valuing potential impairment loss related to long-lived assets ; and (3) valuing potential impairment loss related to goodwill and indefinite-lived intangible assets.
Inventory	Inventory Current inventory consists of parts and small equipment held for use in the ordinary course of business and is valued at the lower of cost (using historical average cost) or net realizable value. Where shipping and handling costs are incurred by the Company, these charges are included in inventory and charged to cost of contract revenue upon use. Non-current inventory consists of spare parts (including engines, cutters and gears) that require special order or long-lead times for manufacture or fabrication, but must be kept on hand to reduce downtime.
Property and Equipment	Property and Equipment Property and equipment are recorded at cost. Ordinary maintenance and repairs that do not improve or extend the useful life of the asset are expensed as incurred. Major renewals and betterments of equipment are capitalized and depreciated generally over three to seven years until the next scheduled maintenance. When property and equipment are retired or otherwise disposed of, the cost and accumulated depreciation are removed from the accounts and any resulting gain or loss is included in results of operations for the respective period. Depreciation is computed using the straight-line method over the estimated useful lives of the related assets for financial statement purposes, as follows: Automobiles and trucks 3 to 5 years Buildings and improvements 5 to 30 years Construction equipment 3 to 15 years Vessels and other equipment 1 to 15 years Office equipment 1 to 5 years The Company generally uses accelerated depreciation methods for tax purposes where appropriate. Dry-docking costs are capitalized and amortized using the straight-line method over a period ranging from three to 15 years. Dry-docking costs include, but are not limited to, the inspection, refurbishment and replacement of steel, engine components, tailshafts, mooring equipment and other parts of the vessel. Amortization related to dry-docking activities is included as a component of depreciation. These costs and the related amortization periods are periodically reviewed to determine if the estimates are accurate. If warranted, a significant upgrade of equipment may result in a revision to the useful life of the asset, in which case the change is accounted for prospectively. Property and equipment are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset or asset group may not be recoverable. Recoverability of assets to be held and used is measured by a comparison of the carrying amount of an asset to estimated undiscounted future cash flows expected to be generated by the asset. If the carrying amount of an asset exceeds its estimated future cash flows, an impairment charge is recognized in the amount by which the carrying amount of the asset exceeds the fair value of the asset. Assets to be disposed of are separately presented in the balance sheet and reported at the lower of the carrying amount or the fair value, less the costs to sell, and are no longer depreciated. There are no assets classified as held for sale as of December 31, 2017.
Goodwill	Goodwill The Company has acquired businesses and assets in purchase transactions that resulted in the recognition of goodwill. Goodwill represents the costs in excess of fair values assigned to the identifiable assets acquired and liabilities assumed in the acquisition. In accordance with U.S. GAAP, acquired goodwill is not amortized, but is subject to impairment testing at least annually at a reporting unit level (as of October 31 st of each year) or more frequently if events or circumstances indicate that the asset may be impaired. The Company determined that its operations comprise two reporting units for goodwill impairment testing, which match its two operating segments for financial reporting. Tests of impairment require a two-step process to be performed to analyze whether or not goodwill has been impaired. The first step of this test, used to identify potential impairment, compares the estimated fair value of a reporting unit with its carrying amount. The second step, if necessary, quantifies the impairment. The Company assesses the fair value of its reporting units based on a weighted average of valuations based on market multiples, discounted cash flows, and consideration of its market capitalization. The key assumptions used in the discounted cash flow valuations are discount rates, weighted average cost of capital and perpetual growth rates applied to cash flow projections. Also inherent in the discounted cash flow valuation models are past performance, projections and assumptions in current operating plans and revenue growth rates over the next five years. These assumptions contemplate business, market and overall economic conditions. Other considerations are assumptions that market participants may use in analysis of comparable companies. The underlying assumptions used for determining fair value, as discussed above, require significant judgment and are susceptible to change from period to period and could potentially cause a material impact to the income statement. In the future, the Company's estimated fair value could be negatively impacted by extended declines in our stock price, changes in macroeconomic indicators, sustained operating losses and other factors which may affect our assessment of fair value. See Note 9 for additional discussion of our goodwill and related goodwill impairment testing.
Intangible Assets	Intangible assets Intangible assets that have finite lives are amortized. In addition, the Company evaluates the remaining useful life of intangible assets in each reporting period to determine whether events and circumstances warrant a revision of the remaining period of amortization. If the estimate of an intangible asset’s remaining life is changed, the remaining carrying value of such asset is amortized prospectively over that revised remaining useful life. Intangible assets that have indefinite lives are not amortized, but are subject to impairment testing at least annually or more frequently if events or circumstances indicate that the asset may be impaired. The Company has one indefinite-lived intangible asset, a trade name, which is tested for impairment annually on October 31 st , or whenever events or circumstances indicate that the carrying amount of the trade name may not be recoverable. Impairment is calculated as the excess of the trade name's carrying value over its fair value. The fair value of the trade name is determined using the relief from royalty method, a variation of the income approach. This method assumes that if a company owns intellectual property, it does not have to "rent" the asset and is, therefore, "relieved" from paying a royalty. Once a supportable royalty rate is determined, the rate is then applied to the projected revenues over the expected remaining life of the intangible assets to estimate the royalty savings. This approach is dependent on a number of factors, including estimates of future growth and trends, royalty rates, discount rates and other variables.
Stock-Based Compensation	Stock-Based Compensation The Company recognizes compensation expense for equity awards over the vesting period based on the fair value of these awards at the date of grant. The computed fair value of these awards is recognized as a non-cash cost over the period the employee provides services, which is typically the vesting period of the award. The fair value of options granted is estimated on the date of grant using the Black-Scholes option-pricing model. The Black-Scholes model requires the use of subjective assumptions in the computation. Changes in these assumptions can cause significant fluctuations in the fair value of the option award. The fair value of restricted stock grants is equivalent to the fair value of the stock issued on the date of grant, and is measured as the mean price of the stock on the day of grant. Compensation expense is recognized only for share-based payments expected to vest. The Company estimates forfeitures at the date of grant based on historical experience and future expectations and this assessment is updated on a periodic basis.
Income Taxes	Income Taxes The Company determines its consolidated income tax provision using the asset and liability method prescribed by U.S. GAAP, which requires the recognition of income tax expense for the amount of taxes payable or refundable for the current period and for deferred tax liabilities and assets for the future tax consequences of events that have been recognized in an entity’s financial statements or tax returns. The Company must make significant assumptions, judgments and estimates to determine its current provision for income taxes, its deferred tax assets and liabilities, and any valuation allowance to be recorded against any deferred tax asset. The current provision for income tax is based upon the current tax laws and the Company’s interpretation of these laws, as well as the probable outcomes of any tax audits. The value of any net deferred tax asset depends upon estimates of the amount and category of future taxable income reduced by the amount of any tax benefits that the Company does not expect to realize. Actual operating results and the underlying amount and category of income in future years could render current assumptions, judgments and estimates of recoverable net deferred taxes inaccurate, thus impacting the Company’s financial position and results of operations. The Company computes deferred income taxes using the liability method. Under the liability method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. Under the liability method, the effect on deferred tax assets and liabilities of a change in tax rates is recognized in income in the period that includes the enactment date. On December 22, 2017, the Act was enacted and signed into law. The Act makes broad and complex changes to the U.S. tax code that significantly affected the Company's income tax rate in 2017. The Act, among other things, reduces the U.S. federal corporate income tax rate from 35% to 21% ; limits the use of foreign tax credits to reduce U.S. income tax liability; eliminates the corporate alternative minimum tax ("AMT") and changes how existing AMT credits can be realized; allows immediate expensing for qualified assets; creates a new limitation on deductible interest expense; repeals the domestic production activities deduction; and limits the deductibility of certain executive compensation and other deductions. Given the widespread applicability of these changes to most U.S. companies, the SEC issued Staff Accounting Bulletin 118 (“SAB 118”) to assist registrants in addressing any uncertainty or diversity in views about the application of FASB ASC Topic 740, "Income Taxes" (ASC 740) in the period of enactment. SAB 118 provides registrants with the option of reporting a reasonable estimate for certain income tax effects of the Act in situations in which a company does not have the necessary information available, prepared or analyzed in reasonable detail to complete the accounting required under ASC 740. The reasonable estimate is reported as a provisional amount in the company’s financial statements during a “measurement period.” The measurement period begins in the reporting period that includes the Act’s enactment date (i.e. the Company’s fourth quarter of 2017) and ends when a company has obtained, prepared and analyzed the information needed in order to complete the accounting requirements under ASC 740. The measurement period should not extend beyond one year from the enactment date (i.e. December 22, 2018). During the measurement period, a company is expected to act in good faith to complete the accounting under ASC 740. Appropriate disclosures will be made to address the Company’s progress toward completing the accounting under the Act and ASC 740 during the measurement period as well as when the accounting is complete. See Note 13 for additional discussion regarding the Company’s application of SAB 118. The Company accounts for uncertain tax positions in accordance with the provisions of ASC 740-10 which prescribes a recognition threshold and measurement attribute for financial statement disclosure of tax positions taken, or expected to be taken, on its consolidated tax return. The Company evaluates and records any uncertain tax positions based on the amount that management deems is more likely than not to be sustained upon examination and ultimate settlement with the tax authorities in the tax jurisdictions in which it operates.
Insurance Coverage	Insurance Coverage The Company maintains insurance coverage for its business and operations. Insurance related to property, equipment, automobile, general liability, and a portion of workers' compensation is provided through traditional policies, subject to a deductible or deductibles. A portion of the Company's workers’ compensation exposure is covered through a mutual association, which is subject to supplemental calls. The marine segment maintains five levels of excess loss insurance coverage, totaling $200 million in excess of primary coverage. The marine segment's excess loss coverage responds to most of its policies when a primary limit of $1 million has been exhausted; provided that the primary limit for Contingent Maritime Employer’s Liability is $10 million and the Watercraft Pollution Policy primary limit is $5 million . The concrete segment maintains five levels of excess loss insurance coverage, totaling $200 million in excess of primary coverage. The concrete segment's excess loss coverage responds to most of its policies when a primary limit of $1 million has been exhausted. If a claim arises and a potential insurance recovery is probable, the impending gain is recognized separately from the related loss. The recovery will only be recognized up to the amount of the loss once the recovery of the claim is deemed probable and any excess gain will fall under contingency accounting and will only be recognized once it is realized. The Company does not net insurance recoveries against the related claim liability as the amount of the claim liability is determined without consideration of the anticipated insurance recoveries from third parties. Separately, the Company’s marine segment employee health care is provided through a trust administered by a third party. Funding of the trust is based on current claims. The administrator has purchased appropriate stop-loss coverage. Losses on these policies up to the deductible amounts are accrued based upon known claims incurred and an estimate of claims incurred but not reported. The accruals are derived from known facts, historical trends and industry averages to determine the best estimate of the ultimate expected loss. Actual claims may vary from estimates. Any adjustments to such reserves are included in the consolidated results of operations in the period in which they become known. The Company's concrete segment employee health care is provided through two policies. A fully funded policy is offered primarily to salaried employees and their dependents while a partially self-funded plan with an appropriate stop-loss is offered primarily to hourly employees and their dependents. The self-funded plan is funded to the maximum exposure and, as a result, expects to receive a partial refund after the policy expiration.
Warranty Costs	Warranty Costs Provision for estimated warranty costs, if any, is made in the period in which such costs become probable and is periodically adjusted to reflect actual experience. The Company historically has not been subject to significant warranty provisions
Recent Accounting Pronouncements	Recent Accounting Pronouncements The FASB issues accounting standards and updates (each an "ASU") from time to time to its Accounting Standards Codification ("ASC"), which is the primary source of U.S. GAAP. The Company regularly monitors ASUs as they are issued and considers applicability to its business. All ASUs are adopted by their respective due dates and in the manner prescribed by the FASB. The following are those recently issued ASUs most likely to affect the presentation of the Company's consolidated financial statements: In January 2017, the FASB issued ASU 2017-04, Simplifying the Test for Goodwill Impairment. The FASB issued this update to simplify how an entity is required to test goodwill for impairment by eliminating Step 2 from the goodwill impairment test. Step 2 measures a goodwill impairment loss by comparing the implied fair value of a reporting unit's goodwill with the carrying amount of that goodwill. The amendments in this update modify the concept of impairment from the condition that exists when the carrying amount of goodwill exceeds its implied fair value to the condition that exists when the carrying amount of a reporting unit exceeds its fair value. The guidance should be applied on a prospective basis and is effective for annual or interim goodwill impairment tests in fiscal years beginning after December 15, 2019. Early adoption is permitted and the Company does not anticipate that the changes will materially impact the financial statements unless a goodwill impairment is recognized in the future. In February 2016, the FASB issued ASU 2016-02, Leases ( Topic 842 ). The Board issued this update to increase the transparency and comparability among organizations by recognizing lease assets and lease liabilities on the balance sheet and disclosing key information about leasing arrangements. The Company anticipates the most significant of the amendments to our organization to be the recognition of assets and liabilities by lessees for those leases classified as operating leases under previous U.S. GAAP. Under the new standard the Company will be required to recognize and measure leases at the beginning of the earliest period presented using a modified retrospective approach. The guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods. In early 2017, the Company established a steering committee to analyze the potential impact of the new standard and identify potential differences that will result from adopting the standard. The Company is currently assessing the effects of adoption on its financial statements. In May 2014, the FASB issued ASU 2014-09, Revenue from Contracts with Customers (Topic 606). This comprehensive new revenue recognition standard will supersede existing revenue guidance under U. S. GAAP. The standard’s core principle is that a company will recognize revenue when it transfers promised goods or services to customers in an amount that reflects the consideration to which the company expects to be entitled in exchange for those goods or services. In doing so, companies will need to use more judgment and make more estimates, including identifying performance obligations in the contract, estimating the amount of variable consideration to include in the transaction price and allocating the transaction price to each separate performance obligation. Topic 606 will be effective for the Company beginning with its first quarter ending March 31, 2018. The guidance permits two methods of adoption: (1) retrospectively to each prior reporting period presented and the cumulative effect would be recognized at the earliest period shown (i.e. the full retrospective method); or (2) retrospectively with the cumulative effect of initially applying the guidance recognized at the date of initial application (i.e the modified retrospective method). The Company will adopt the standard using the modified retrospective method which will involve recognizing in beginning retained earnings an adjustment for the cumulative effect of the change and will be applied to contracts with customers that are not substantially complete as of January 1, 2018. The Company established a steering committee consisting of representatives from various business segments within the organization. The purpose of this committee was to analyze the impact of the new standard on the Company's business by reviewing the current revenue practices to identify potential differences that would result from applying the requirements of the new standard to revenue contracts. In addition, the Company analyzed the possibility of any necessary changes to current business processes, systems and controls to support recognition and disclosure under the new standard. Based on its assessment of the new standard as of December 31, 2017, the Company will continue to recognize revenue over time, measuring progress using the cost-to-cost method. It does not expect Topic 606 to have a material impact on its concrete segment’s revenue. The most significant impact of Topic 606 will be related to its marine segment, specifically in the following areas: • Multiple performance obligations - In accordance with Topic 606, construction contracts with customers, including those related to contract modifications will be reviewed to determine if there are multiple performance obligations. If separate performance obligations are identified, the timing of revenue recognition could be impacted. Based on our review of currently active construction contracts with customers, the Company identified certain contracts in the marine segment that have multiple performance obligations. However, based on its assessment, the Company does not believe the impact on retained earnings is material. • Upfront costs - In accordance with Topic 606, these costs are required to be capitalized as an asset and amortized over the duration of the related contract. For the Company, such costs are generally comprised of costs incurred to mobilize equipment and labor to a job site or other upfront costs such as bonds or insurance, which are expensed as incurred under current accounting practices. The Company identified certain currently active construction contracts in the marine segment with upfront costs. However, based on its assessment, the Company does not believe the impact on retained earnings is material. The Company also anticipates expanding our revenue recognition disclosure due to the new qualitative and quantitative requirements under the new standard, which may include a separate footnote. During the periods presented in these financial statements, the Company implemented other new accounting pronouncements other than those noted above that are discussed in the notes where applicable.

Summary of Significant Accoun31

Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2017
Accounting Policies [Abstract]
Depreciable lives of property and equipment	Automobiles and trucks 3 to 5 years Buildings and improvements 5 to 30 years Construction equipment 3 to 15 years Vessels and other equipment 1 to 15 years Office equipment 1 to 5 years The following is a summary of property and equipment at December 31, 2017 and December 31, 2016 : December 31, December 31, Automobiles and trucks $ 1,940 $ 2,525 Building and improvements 38,062 37,269 Construction equipment 166,203 165,023 Vessels and other equipment 85,113 88,659 Office equipment 8,039 7,125 299,357 300,601 Less: accumulated depreciation (191,407 ) (181,293 ) Net book value of depreciable assets 107,950 119,308 Construction in progress 245 543 Land 38,083 38,231 $ 146,278 $ 158,082

Business Acquisition (Tables)

Business Acquisition (Tables)	12 Months Ended
	Dec. 31, 2017
Business Combinations [Abstract]
Schedule of recognized identified assets acquired and liabilities assumed	Accounts receivable $ 3,239 Retainage 1,860 Fixed assets, net 2,098 Other 9 Goodwill 2,562 Other intangible assets 878 Accounts payable (2,017 ) Accrued expenses and other current liabilities (1,080 ) Contingent consideration (456 ) Deferred tax liability (1,093 ) Total Acquisition Consideration at April 9, 2017 $ 6,000 Working capital adjustment (all attributable to Goodwill) 557 Total Acquisition Consideration $ 6,557
Summary of Pro Forma Results	Pro Forma Results For the Year Ended December 31, 2016 Contract revenues $ 610,695 Operating income from continuing operations $ 5,593 Net loss $ (2,677 ) Basic loss per share $ (0.10 ) Diluted loss per share $ (0.10 )

Concentration of Risk and Ent33

Concentration of Risk and Enterprise Wide Disclosures (Tables)	12 Months Ended
	Dec. 31, 2017
Accounts receivable
Concentration Risk [Line Items]
Schedules of concentration of risk, by risk factor	The table below presents the concentrations of current receivables (trade and retainage) at December 31, 2017 and December 31, 2016 , respectively: December 31, 2017 December 31, 2016 Federal Government $ 3,509 3 % $ 5,542 4 % State Governments 4,503 3 % 9,302 7 % Local Governments 18,256 15 % 20,886 16 % Private Companies 97,874 79 % 96,673 73 % Total receivables $ 124,142 100 % $ 132,403 100 %
Contract revenues
Concentration Risk [Line Items]
Schedules of concentration of risk, by risk factor	dditionally, the table below represents concentrations of contract revenue by type of customer for the year s ended December 31, 2017 , 2016 and 2015 . 2017 % 2016 % 2015 % Federal Government $ 63,823 11 % $ 40,361 7 % $ 45,439 10 % State Governments 42,613 7 % 37,700 7 % 42,026 9 % Local Governments 91,592 16 % 94,461 16 % 130,187 28 % Private Companies 380,525 66 % 405,714 70 % 248,846 53 % Total contract revenues $ 578,553 100 % $ 578,236 100 % $ 466,498 100 %

Contracts in Progress (Tables)

Contracts in Progress (Tables)	12 Months Ended
	Dec. 31, 2017
Contractors [Abstract]
Contracts in progress	Contracts in progress are as follows at December 31, 2017 and December 31, 2016 : December 31, December 31, Costs incurred on uncompleted contracts $ 668,848 $ 802,140 Estimated earnings 120,751 143,975 789,599 946,115 Less: Billings to date (777,516 ) (933,828 ) $ 12,083 $ 12,287 Included in the accompanying consolidated balance sheets under the following captions: Costs and estimated earnings in excess of billings on uncompleted contracts 46,006 $ 39,968 Billings in excess of costs and estimated earnings on uncompleted contracts (33,923 ) (27,681 ) $ 12,083 $ 12,287

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2017
Property, Plant and Equipment [Abstract]
Summary of property and equipment	Automobiles and trucks 3 to 5 years Buildings and improvements 5 to 30 years Construction equipment 3 to 15 years Vessels and other equipment 1 to 15 years Office equipment 1 to 5 years The following is a summary of property and equipment at December 31, 2017 and December 31, 2016 : December 31, December 31, Automobiles and trucks $ 1,940 $ 2,525 Building and improvements 38,062 37,269 Construction equipment 166,203 165,023 Vessels and other equipment 85,113 88,659 Office equipment 8,039 7,125 299,357 300,601 Less: accumulated depreciation (191,407 ) (181,293 ) Net book value of depreciable assets 107,950 119,308 Construction in progress 245 543 Land 38,083 38,231 $ 146,278 $ 158,082

Fair Value Schedule of Fair Val

Fair Value Schedule of Fair Value, Assets and Liabilities measured on a recurring basis (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]	The following table sets forth by level within the fair value hierarchy the Company's recurring financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2017 and December 31, 2016 : Fair Value Measurements Carrying Value Level 1 Level 2 Level 3 December 31, 2017 Assets: Cash surrender value of life insurance policy $ 1,712 — 1,712 — Liabilities: Derivatives $ 38 — 38 — December 31, 2016 Assets: Cash surrender value of life insurance policy $ 1,188 — 1,188 — Liabilities: Derivatives $ 447 — 447 —

Fair Value (Tables)

Fair Value (Tables)	12 Months Ended
	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis	The following table sets forth by level within the fair value hierarchy the Company's recurring financial assets and liabilities that were accounted for at fair value on a recurring basis as of December 31, 2017 and December 31, 2016 : Fair Value Measurements Carrying Value Level 1 Level 2 Level 3 December 31, 2017 Assets: Cash surrender value of life insurance policy $ 1,712 — 1,712 — Liabilities: Derivatives $ 38 — 38 — December 31, 2016 Assets: Cash surrender value of life insurance policy $ 1,188 — 1,188 — Liabilities: Derivatives $ 447 — 447 —

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2017
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of changes in goodwill	The table below summarizes changes in goodwill recorded by the Company during the periods ended December 31, 2017 and 2016 : December 31, December 31, Beginning balance, January 1 $ 66,351 $ 65,982 Additions 3,132 369 Ending balance $ 69,483 $ 66,351
Schedule of changes and amortization of finite-lived intangible assets	The tables below present the activity and amortizations of finite-lived intangible assets: December 31, December 31, Intangible assets, January 1 $ 34,362 $ 34,362 Additions 878 — Total intangible assets, end of year 35,240 34,362 Accumulated amortization, January 1 $ (19,220 ) $ (11,933 ) Current year amortization (4,736 ) (7,287 ) Total accumulated amortization (23,956 ) (19,220 ) Net intangible assets, end of year $ 11,284 $ 15,142
Summary of Finite-lived Intangible Assets Amortization Expense	Future expense remaining of approximately $11.3 million will be amortized as follows: 2018 $ 3,389 2019 2,640 2020 2,069 2021 1,521 2022 1,239 Thereafter 426 $ 11,284

Accrued Liabilities (Tables)

Accrued Liabilities (Tables)	12 Months Ended
	Dec. 31, 2017
Payables and Accruals [Abstract]
Schedule of accrued liabilities	Accrued liabilities at December 31, 2017 and 2016 consisted of the following: 2017 2016 Accrued salaries, wages and benefits $ 9,632 $ 10,818 Accrual for insurance liabilities 5,233 5,223 Property taxes 513 1,615 Sales taxes 1,836 1,722 Interest 46 19 Other accrued expenses 613 549 $ 17,873 $ 19,946

Long-term Debt and Line of Cr40

Long-term Debt and Line of Credit (Tables)	12 Months Ended
	Dec. 31, 2017
Debt Disclosure [Abstract]
Schedule of Debt	The Company's obligations under debt arrangements consisted of the following: December 31, 2017 December 31, 2016 Principal Debt Issuance Costs (1) Total Principal Debt Issuance Costs (1) Total Revolving line of credit $ 10,000 $ (317 ) $ 9,683 $ 8,000 $ (252 ) $ 7,748 Term loan - current 13,500 (427 ) 13,073 11,813 (373 ) 11,440 Total current debt 23,500 (744 ) 22,756 19,813 (625 ) 19,188 Term loan - long-term 65,250 (2,065 ) 63,185 84,750 (2,673 ) 82,077 Total debt $ 88,750 $ (2,809 ) $ 85,941 $ 104,563 $ (3,298 ) $ 101,265 (1) Total debt issuance costs, include underwriter fees, legal fees, syndication fees, and fees related to the execution of the First, Second, and Third Amendments to the Credit Agreement as previously discussed.
Debt Maturity Schedule	The table below outlines the total remaining payment amounts annually for the term loan through maturity of the Credit Facility: 2018 13,500 2019 15,188 2020 50,062 $ 78,750

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Schedule of components of income tax expense (benefit)	The following table presents the components of our consolidated income tax (benefit) expense for the years ended December 31, 2017 , 2016 and 2015 : Current Deferred Total Year ended December 31, 2017 U.S. Federal (a) $ (780 ) $ (3,986 ) $ (4,766 ) State and local 550 $ (180 ) $ 370 Foreign (145 ) — (145 ) $ (375 ) $ (4,166 ) $ (4,541 ) Year ended December 31, 2016 U.S. Federal $ 35 $ (1,093 ) $ (1,058 ) State and local 511 1,519 2,030 Foreign 284 325 609 $ 830 $ 751 $ 1,581 Year ended December 31, 2015 U.S. Federal $ 3 $ (3,768 ) $ (3,765 ) State and local (60 ) 883 823 Foreign 423 — 423 $ 366 $ (2,885 ) $ (2,519 )
Schedule of effective income tax reconciliation	The Company’s income tax provision reconciles to the provision at the statutory U.S. federal income tax rate for each year ended December 31, as follows: 2017 2016 2015 Statutory amount (computed at 35%) $ (1,449 ) $ (714 ) $ (3,703 ) Re-measurement of deferred tax assets (a) (7,451 ) — — Valuation allowance on foreign tax credits (a) 1,514 — — State income tax, net of federal benefit 168 94 (709 ) Permanent differences, other 505 99 43 Permanent differences, incentive stock options 447 224 298 Valuation allowance, other (77 ) 1,769 1,552 Uncertain tax provision 1,614 — — Other 188 109 — Consolidated income tax provision $ (4,541 ) $ 1,581 $ (2,519 ) Consolidated effective tax rate 109.7 % (77.5 )% 23.8 %
Schedule of deferred tax assets and liabilities	The Company’s deferred tax assets and liabilities are as follows: December 31, 2017 December 31, 2016 Current Long- term (a) Current Long-term Assets related to: Accrued liabilities $ — $ 1,226 $ 2,322 $ — Intangible assets — 3,010 — 4,517 Net operating loss carryforward — 6,912 — 7,455 Valuation allowance — (3,942 ) — (3,321 ) Non-qualified stock options — 762 112 1,367 Foreign tax credits — 1,751 — 2,035 Valuation allowance on foreign tax credits — (1,514 ) — — AMT credits — — — 780 Other — 215 45 16 Total assets — 8,420 2,479 12,849 Liabilities related to: Depreciation and amortization — (15,788 ) — (25,326 ) Goodwill — (5,178 ) — (6,502 ) Deferred revenue on maintenance contracts — (597 ) (429 ) — Other — (100 ) (37 ) (21 ) Total liabilities — (21,663 ) (466 ) (31,849 ) Net deferred (liabilities) assets $ — $ (13,243 ) $ 2,013 $ (19,000 )
Schedule of net deferred tax assets and liabilities as reported in the balance sheet	As reported in the Consolidated Balance Sheets: December 31, 2017 December 31, 2016 Net current deferred tax assets — 2,013 Net non-current deferred tax liabilities (13,243 ) (19,000 ) Total net deferred tax liabilities: $ (13,243 ) $ (16,987 )
Schedule of unrecognized tax benefits	The change in the total gross unrecognized tax benefits and prior year audit resolutions of the Company during the year ended December 31, 2017 is reconciled in the table below: 2017 Balances at beginning of the year $ — Additions based on tax position related to current year — Additions based on tax positions related to prior years 1,614 Reductions based on tax positions related to current year — Reductions based on tax positions related to prior years — Settlements with tax authorities — Lapse of statute of limitations — Balance at the end of year $ 1,614

Earnings (Loss) Per Share (Tabl

Earnings (Loss) Per Share (Tables)	12 Months Ended
	Dec. 31, 2017
Earnings Per Share [Abstract]
Schedule of earnings per share, basic and diluted	The following table reconciles the denominators used in the computations of both basic and diluted earnings (loss) per share: Year ended December 31, 2017 2016 2015 Basic: Weighted average shares outstanding 28,029,936 27,536,967 27,366,528 Diluted: Total basic weighted average shares outstanding 28,029,936 27,536,967 27,366,528 Effect of dilutive securities: Common stock options 324,344 — — Total weighted average shares outstanding assuming dilution 28,354,280 27,536,967 27,366,528 Anti-dilutive stock options — — — Shares of common stock issued from the exercise of stock options 229,551 13,850 3,970

Stock-Based Compensation (Table

Stock-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2017
Disclosure of Compensation Related Costs, Share-based Payments [Abstract]
Schedule of restricted stock activity	The following table summarizes the restricted stock activity under the Company's equity incentive plans : Number of Shares Weighted Average Fair Value Per Share Nonvested at January 1, 2015 235,863 $ 8.63 Granted 38,660 $ 5.82 Vested (134,545 ) $ 6.84 Forfeited/repurchased shares (19,824 ) $ 11.35 Nonvested at December 31, 2015 120,154 $ 9.28 Granted 407,002 $ 4.96 Vested (147,259 ) $ 6.62 Forfeited/repurchased shares (7,591 ) $ 7.08 Nonvested at December 31, 2016 372,306 $ 5.66 Granted 345,913 $ 7.22 Vested (225,406 ) $ 7.25 Forfeited/repurchased shares (120,353 ) $ 6.08 Nonvested at December 31, 2017 372,460 $ 6.01
Schedule of stock options activity	The following table summarizes the stock option activity under the Company's equity incentive plans: Number of Shares Weighted Average Exercise Price Per Share Weighted Average Contractual Life (Years) Aggregate Intrinsic Value Outstanding at January 1, 2015 2,056,898 $ 9.86 Granted 143,862 $ 5.82 Exercised (3,970 ) $ 6.00 Forfeited (46,890 ) $ 11.72 Outstanding at December 31, 2015 2,149,900 $ 9.56 Granted 587,862 $ 4.98 Exercised (13,850 ) $ 4.86 Forfeited (374,466 ) $ 9.89 Outstanding at December 31, 2016 2,349,446 $ 8.39 Granted 425,204 $ 7.22 Exercised (229,551 ) $ 5.75 Forfeited (633,978 ) $ 10.36 Outstanding at December 31, 2017 1,911,121 $ 7.79 Vested and expected to vest at December 31, 2017 2,024,130 $ 7.69 5.26 $ 2,872 Exercisable at December 31, 2017 1,462,481 $ 8.18 3.82 $ 2,054
Schedule of stock option valuation assumptions	The Company calculates the fair value of each option on the date of grant using the Black-Scholes pricing model and the following weighted-average assumptions in each year: 2017 2016 2015 Weighted average grant-date fair value of options granted $ 7.22 $ 4.97 $ 5.82 Risk-free interest rate 1.46 % 1.06 % 0.97 % Expected volatility 48 % 49 % 38 % Expected term of options (in years) 3.0 3.0 3.0 Dividend yield — % — % — %
Schedule of intrinsic value of options exercised and fair value of shares vested	2017 2016 2015 Total intrinsic value of options exercised $ 706 $ 53 $ 17 Total fair value of shares vested $ 855 $ 986 $ 1,226

Employee Benefits (Tables)

Employee Benefits (Tables)	12 Months Ended
	Dec. 31, 2017
Compensation and Retirement Disclosure [Abstract]
Schedule of multiemployer plans	The following table presents the Company's participation in these plans: Pension Protection Act ("PPA") Certified Zone Status (1) FIP/RP Status Contributions Expiration of Collective Bargaining Agreement Employer Identification Number Surcharge Imposed Pension Trust Fund 2017 2016 P/I (2) 2017 2016 2015 International Union of Operating Engineers - Employers Construction Industry Retirement Plan - Local 302 and 612 Trust Funds 91-6028571 Green Green N/A $ 1,974 $ 2,158 $ 1,518 — 2018 Associated General Contractors of Washington Carpenter, Piledrivers, and Millwrights 91-6029051 91-6029049 Green Green N/A $ 693 $ 938 $ 748 — 2018 Alaska Carpenters Trust Fund 92-0120866 Green Green N/A $ 396 $ 889 $ 807 — 2020 Alaska Laborers Trust Fund 91-6028298 Yellow Yellow P $ 218 $ 126 $ 110 — 2017 (1) The most recent PPA zone status available in 2017 and 2016 is for the plan's year end during 2016 and 2015, respectively. Zone status is based on information received from the plan and is indicative of the plans funding status. Among other factors, plans in the red zone are generally less than 65 percent funded, plans in the orange zone are less than 80 percent funded and have an Accumulated Funding Deficiency in the current year or projected into the next six years, plans in the yellow zone are less than 80 percent funded, and plans in the green zone are at least 80 percent funded. (2) The FIP/RP Status P/I column indicates plans for which a financial improvement plan ("FIP") or a rehabilitation plan ("RP") is either pending ("P"), or implemented ("I").

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2017
Commitments and Contingencies Disclosure [Abstract]
Schedule of future minimum rental payments for operating leases	Future minimum lease payments under non-cancelable operating leases as of December 31, 2017 are as follows: Amount Year ended December 31, 2018 $ 7,371 2019 6,560 2020 5,364 2021 3,247 2022 1,824 Thereafter 12,947 $ 37,313

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2017
Segment Reporting [Abstract]
Schedule of Segment Reporting	Segment information for the periods presented is provided as follows: Year Ended December 31, 2017 Year Ended December 31, 2016 Marine Contract revenues $ 285,736 $ 284,632 Operating loss (18,406 ) (12,403 ) Depreciation and amortization expense (20,370 ) (21,398 ) Total assets $ 260,935 $ 279,362 Property, plant and equipment, net 128,421 143,425 Concrete Contract revenues $ 292,817 $ 293,604 Operating income 19,944 16,477 Depreciation and amortization expense (9,121 ) (12,764 ) Total assets $ 172,350 $ 168,314 Property, plant and equipment, net 17,857 14,657

Selected Quarterly Financial 47

Selected Quarterly Financial Data (Tables)	12 Months Ended
	Dec. 31, 2017
Quarterly Financial Information Disclosure [Abstract]
Schedule of quarterly financial information	The following tables set forth selected unaudited financial information for the eight quarters in the two-year period ended December 31, 2017 . This information has been prepared on the same basis as the audited financial statements and, in the opinion of management, contains all adjustments necessary for a fair presentation. First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (in thousands, except per share data) 2017 Revenues $ 138,757 $ 137,420 $ 140,162 $ 162,214 $ 578,553 Gross profit 12,985 15,397 10,757 27,751 66,890 Operating (loss) income (1,482 ) (2,466 ) (5,354 ) 10,840 1,538 (Loss) income before income taxes (2,827 ) (3,917 ) (6,703 ) 9,306 (4,141 ) Net (loss) income (1,808 ) (2,293 ) (5,037 ) 9,538 400 (Loss) earnings per share: Basic $ (0.07 ) $ (0.08 ) $ (0.18 ) $ 0.34 $ 0.01 Diluted $ (0.07 ) $ (0.08 ) $ (0.18 ) $ 0.34 $ 0.01 First Quarter Second Quarter Third Quarter Fourth Quarter Total Year (in thousands, except per share data) 2016 Revenues $ 129,623 $ 140,301 $ 164,017 $ 144,295 $ 578,236 Gross profit 14,710 16,946 24,169 11,657 67,482 Operating (loss) income (455 ) 281 9,531 (5,283 ) 4,074 (Loss) income before income taxes (1,958 ) (1,310 ) 7,963 (6,734 ) (2,039 ) Net (loss) income (1,208 ) (808 ) 4,739 (6,343 ) (1 ) (3,620 ) (Loss) earnings per share: Basic $ (0.04 ) $ (0.03 ) $ 0.17 $ (0.23 ) $ (0.13 ) Diluted $ (0.04 ) $ (0.03 ) $ 0.17 $ (0.23 ) $ (0.13 ) (1) - Fourth quarter 2016 net loss includes $0.8 million of tax expense that represents an out of period adjustment associated with deferred taxes. Management evaluated the effect of the adjustment on the Company's financial statements based on SEC Staff Accounting Bulleting ("SAB") No. 99 and SAB 108 and concluded that it was immaterial to the current and prior year's financial statements.

Description of Business and B48

Description of Business and Basis of Presentation (Details) - segment	6 Months Ended	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2017	Dec. 31, 2016
Organization, Consolidation and Presentation of Financial Statements [Abstract]
Number of reportable segments	2	2	2

Summary of Significant Accoun49

Summary of Significant Accounting Policies - Accounts Receivable (Details) - USD ($) $ in Millions	Dec. 31, 2017	Dec. 31, 2016
Accounts Receivable [Abstract]
Contract receivable retention	$ 39.2	$ 40.2
Retainage, long-term	$ 8

Summary of Significant Accoun50

Summary of Significant Accounting Policies - Advertising (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Advertising Expense [Abstract]
Advertising expense	$ 150	$ 178	$ 114

Summary of Significant Accoun51

Summary of Significant Accounting Policies - Depreciable Lives of Property and Equipment (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Property, Plant and Equipment [Line Items]
Depreciation expense									$ 24,800	$ 26,900	$ 23,700
Net income (loss)									$ 400	$ (3,620)	$ (8,060)
Diluted (in dollars per share)	$ 0.34	$ (0.18)	$ (0.08)	$ (0.07)	$ (0.23)	$ 0.17	$ (0.03)	$ (0.04)	$ 0.01	$ (0.13)	$ (0.29)
Automobiles and trucks | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									3 years
Automobiles and trucks | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									5 years
Building and improvements | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									5 years
Building and improvements | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									30 years
Construction equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									3 years
Construction equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									15 years
Dredges and dredging equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									1 year
Dredges and dredging equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									15 years
Office equipment | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									1 year
Office equipment | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									5 years
Dry-docking capitalized costs | Minimum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									3 years
Dry-docking capitalized costs | Maximum
Property, Plant and Equipment [Line Items]
Property and equipment useful life									15 years

Summary of Significant Accoun52

Summary of Significant Accounting Policies - Goodwill (Details) - USD ($) $ in Thousands	Oct. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill		$ 69,483	$ 66,351	$ 65,982
Revenue growth rate implied in reporting units valuations, number of years projected		5 years
Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill		$ 33,800
Discount rate	35.00%
Percentage of fair value in excess of carrying amt	12.80%
Commercial Concrete Segment
Goodwill [Line Items]
Goodwill		$ 35,700
Discount rate	30.00%
Percentage of fair value in excess of carrying amt	13.70%
Estimate of Fair Value Measurement | Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill impairment, segment value	$ 212,000
Estimate of Fair Value Measurement | Commercial Concrete Segment
Goodwill [Line Items]
Goodwill impairment, segment value	153,000
Reported Value Measurement | Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill impairment, segment value	188,000
Reported Value Measurement | Commercial Concrete Segment
Goodwill [Line Items]
Goodwill impairment, segment value	$ 134,500

Summary of Significant Accoun53

Summary of Significant Accounting Policies - Intangible Assets (Details) $ in Millions	Oct. 31, 2015USD ($)
Trade Names | Estimate of Fair Value Measurement
Finite-Lived Intangible Assets [Line Items]
Intangible assets, value	$ 9.2

Summary of Significant Accoun54

Summary of Significant Accounting Policies - Insurance Coverage (Details)	12 Months Ended
	Dec. 31, 2017USD ($)levelspolicy	Dec. 31, 2016USD ($)
Insurance Coverage [Line Items]
Levels of insurance coverage maintained by the Company | levels	5
Number of Insurance Policies | policy	2
Accrual for insurance liabilities	$ 5,233,000	$ 5,223,000
Heavy Civil Marine Construction Segment
Insurance Coverage [Line Items]
Levels of insurance coverage maintained by the Company | levels	5
Amount in excess of primary insurance coverage	$ 200,000,000
Heavy Civil Marine Construction Segment | Other liability policies
Insurance Coverage [Line Items]
Primary limit of insurance coverage	1,000,000
Heavy Civil Marine Construction Segment | Maritime employer's liability
Insurance Coverage [Line Items]
Primary limit of insurance coverage	10,000,000
Heavy Civil Marine Construction Segment | Watercraft pollution policy
Insurance Coverage [Line Items]
Primary limit of insurance coverage	$ 5,000,000
Commercial Concrete Segment
Insurance Coverage [Line Items]
Levels of insurance coverage maintained by the Company | levels	5
Amount in excess of primary insurance coverage	$ 200,000,000
Commercial Concrete Segment | Other liability policies
Insurance Coverage [Line Items]
Primary limit of insurance coverage	$ 1,000,000

Summary of Significant Accoun55

Summary of Significant Accounting Policies - Revenue Recognition (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Revenue, Major Customer [Line Items]
Contract revenues	$ 162,214	$ 140,162	$ 137,420	$ 138,757	$ 144,295	$ 164,017	$ 140,301	$ 129,623	$ 578,553	$ 578,236	$ 466,498
Customer One
Revenue, Major Customer [Line Items]
Contract revenues			$ 12,300

Summary of Significant Accoun56

Summary of Significant Accounting Policies - Recent Accounting Pronouncements (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accounting Policies [Abstract]
Deferred tax asset	$ 0	$ 2,013

Summary of Significant Accoun57

Summary of Significant Accounting Policies Income Taxes (Details)	12 Months Ended
	Dec. 31, 2016	Dec. 31, 2015
Accounting Policies [Abstract]
Federal income tax rate	35.00%	35.00%

Business Acquisition - Narrati

Business Acquisition - Narrative (Details) - USD ($) $ in Thousands	Apr. 10, 2017	Aug. 05, 2015	Dec. 31, 2017	Jun. 30, 2017	Dec. 31, 2016	Dec. 31, 2015	Apr. 09, 2017
Business Acquisition [Line Items]
Federal statutory tax rate					35.00%	35.00%
Tony Bagliore Concrete, Inc. (TBC)
Business Acquisition [Line Items]
Payments to acquire businesses	$ 6,000
Contingent considerations			$ 2,000	$ 2,000
Contingent considerations, fair value							$ 456
Goodwill, net of working capital adjustment							$ 3,100
GLM Concrete Solutions, LLC
Business Acquisition [Line Items]
Issued and outstanding membership interest acquired		49.00%
TAS Commercial Concrete
Business Acquisition [Line Items]
Payments to acquire businesses		$ 112,000
Goodwill, net of working capital adjustment		32,600
Goodwill expected to be tax deductible		$ 32,600
Goodwill, tax basis, amortization period		15 years
Minimum | Tony Bagliore Concrete, Inc. (TBC)
Business Acquisition [Line Items]
Property and equipment useful life		3 years
Maximum | Tony Bagliore Concrete, Inc. (TBC)
Business Acquisition [Line Items]
Property and equipment useful life		15 years

Business Acquisition - Recogni

Business Acquisition - Recognized Identified Assets Acquired and Liabilities Assumed (Details) - USD ($) $ in Thousands	Apr. 09, 2017	Jun. 17, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Business Acquisition [Line Items]
Goodwill			$ 69,483	$ 66,351	$ 65,982
Tony Bagliore Concrete, Inc. (TBC)
Business Acquisition [Line Items]
Accounts receivable	$ 3,239
Retainage	1,860
Fixed assets, net	2,098
Other	9
Goodwill	2,562
Other intangible assets	878
Accounts payable	(2,017)
Accrued expenses and other current liabilities	(1,080)
Contingent consideration	(456)
Deferred tax liability	(1,093)
Working capital adjustment (all attributable to Goodwill)	557
Total Acquisition Consideration, Final	$ 6,000		$ 6,557
TAS Commercial Concrete
Business Acquisition [Line Items]
Working capital adjustment (all attributable to Goodwill)		$ 400

Business Acquisition - Pro Form

Business Acquisition - Pro Forma Information (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Business Acquisition, Pro Forma Information [Abstract]
Contract revenues	$ 610,695	$ 602,537
Operating income from continuing operations	5,593	1,541
Net loss	$ (2,677)	$ 1,311
Basic (loss) earnings per share (USD per share)	$ (0.10)	$ 0.05
Diluted (loss) earnings per share (USD per share)	$ (0.10)	$ 0.05

Concentration of Risk and Ent61

Concentration of Risk and Enterprise Wide Disclosures (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Concentration Risk [Line Items]
Contract revenues	$ 162,214	$ 140,162	$ 137,420	$ 138,757	$ 144,295	$ 164,017	$ 140,301	$ 129,623	$ 578,553	$ 578,236	$ 466,498
Foreign
Concentration Risk [Line Items]
Contract revenues, percent									1.60%	1.30%	4.10%
Customer concentration risk | Trade and contract retainage receivables
Concentration Risk [Line Items]
Trade and retainage receivables	124,142				132,403				$ 124,142	$ 132,403
Concentration risk, percentage									100.00%	100.00%
Customer concentration risk | Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									100.00%	100.00%	100.00%
Contract revenues									$ 578,553	$ 578,236	$ 466,498
Customer concentration risk | Federal Government | Trade and contract retainage receivables
Concentration Risk [Line Items]
Trade and retainage receivables	3,509				5,542				$ 3,509	$ 5,542
Concentration risk, percentage									3.00%	4.00%
Customer concentration risk | Federal Government | Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									11.00%	7.00%	10.00%
Contract revenues									$ 63,823	$ 40,361	$ 45,439
Customer concentration risk | State Governments | Trade and contract retainage receivables
Concentration Risk [Line Items]
Trade and retainage receivables	4,503				9,302				$ 4,503	$ 9,302
Concentration risk, percentage									3.00%	7.00%
Customer concentration risk | State Governments | Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									7.00%	7.00%	9.00%
Contract revenues									$ 42,613	$ 37,700	$ 42,026
Customer concentration risk | Local Governments | Trade and contract retainage receivables
Concentration Risk [Line Items]
Trade and retainage receivables	18,256				20,886				$ 18,256	$ 20,886
Concentration risk, percentage									15.00%	16.00%
Customer concentration risk | Local Governments | Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									16.00%	16.00%	28.00%
Contract revenues									$ 91,592	$ 94,461	$ 130,187
Customer concentration risk | Private Companies | Trade and contract retainage receivables
Concentration Risk [Line Items]
Trade and retainage receivables	$ 97,874				$ 96,673				$ 97,874	$ 96,673
Concentration risk, percentage									79.00%	73.00%
Customer concentration risk | Private Companies | Contract revenues
Concentration Risk [Line Items]
Concentration risk, percentage									66.00%	70.00%	53.00%
Contract revenues									$ 380,525	$ 405,714	$ 248,846

Contracts in Progress (Details)

Contracts in Progress (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Contractors [Abstract]
Costs incurred on uncompleted contracts	$ 668,848	$ 802,140
Estimated earnings	120,751	143,975
Costs incurred and estimated earnings on uncompleted contracts	789,599	946,115
Less: Billings to date	(777,516)	(933,828)
Costs and estimated earnings in excess of billings on uncompleted contracts, net	12,083	12,287
Costs and estimated earnings in excess of billings on uncompleted contracts	46,006	39,968
Billings in excess of costs and estimated earnings on uncompleted contracts	$ (33,923)	$ (27,681)

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 299,357	$ 300,601
Less: accumulated depreciation	(191,407)	(181,293)
Property, Pant and Equipment, Net Book Value of Depreciable Assets	107,950	119,308
Property and equipment, net	146,278	158,082
Automobiles and trucks
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	1,940	2,525
Building and improvements
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	38,062	37,269
Construction equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	166,203	165,023
Dredges and dredging equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	85,113	88,659
Office equipment
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	8,039	7,125
Construction in progress
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	245	543
Land
Property, Plant and Equipment [Line Items]
Property, plant and equipment, gross	$ 38,083	$ 38,231

Property and Equipment Narrativ

Property and Equipment Narrative (Details) - USD ($) $ in Thousands	9 Months Ended	12 Months Ended
	Sep. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Long Lived Assets Held-for-sale [Line Items]
Depreciation expense		$ 24,800	$ 26,900	$ 23,700
Assets disposed of in 2017		5,400
Proceeds from sale of property and equipment		6,826	2,152	2,708
Loss on Disposition of Property Plant Equipment		(674)	(1,579)	466
Impairment of long-lived assets held-for-use		1,000	6,400
Insurance claims pending		925	0	$ 0
Heavy Civil Marine Construction Segment
Long Lived Assets Held-for-sale [Line Items]
Proceeds from sale of property and equipment		4,500
Loss on Disposition of Property Plant Equipment	$ 100	$ 900
Other Nonoperating Income (Expense)
Long Lived Assets Held-for-sale [Line Items]
Impairment of long-lived assets held-for-use			900
Other Nonoperating Income (Expense) | Heavy Civil Marine Construction Segment
Long Lived Assets Held-for-sale [Line Items]
Assets disposed of in 2017			$ 1,700

Inventory (Details)

Inventory (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Inventory Disclosure [Abstract]
Inventory	$ 4,386	$ 5,392
Inventory, non-current	$ 4,915	$ 3,998

Fair Value - Narrative (Detail

Fair Value - Narrative (Details) $ in Thousands	Dec. 31, 2017USD ($)employee	Dec. 31, 2016USD ($)
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Life Insurance, number of employees | employee	4
Life Insurance, face amount	$ 11,100
Assets | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance	1,712	$ 1,188
Assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance	0	0
Assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance	1,712	1,188
Assets | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash surrender value of life insurance	0	0
Liability
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Fair Value, Net	100
Liability | Fair Value, Measurements, Recurring
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Fair Value, Net	38	447
Liability | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 1
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Fair Value, Net	0	0
Liability | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 2
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Fair Value, Net	38	447
Liability | Fair Value, Measurements, Recurring | Fair Value, Inputs, Level 3
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Derivatives, Fair Value, Net	0	0
Reported Value Measurement [Member]
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Fair value of debt	$ 88,800	$ 104,600

Goodwill and Intangible Asset67

Goodwill and Intangible Assets - Goodwill Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning balance, January 1	$ 66,351	$ 65,982
Additions	3,132	369
Ending balance	$ 69,483	$ 66,351

Goodwill and Intangible Asset68

Goodwill and Intangible Assets - Finite-lived Intangible Assets Roll Forward (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Finite-lived Intangible Assets, Gross [Roll Forward]
Intangible assets, January 1	$ 34,362	$ 34,362
Additions	878	0
Total intangible assets, end of year	35,240	34,362
Accumulated Amortization [Roll Forward]
Accumulated amortization, January 1	(19,220)	(11,933)
Current year amortization	(4,736)	(7,287)
Total accumulated amortization	(23,956)	(19,220)
Net intangible assets, end of year	$ 11,284	$ 15,142

Goodwill and Intangible Asset69

Goodwill and Intangible Assets - Narrative (Details) - USD ($) $ in Thousands	Apr. 10, 2017	Dec. 31, 2017	Dec. 31, 2016	Aug. 05, 2015
Finite-Lived Intangible Assets [Line Items]
Amortization expense		$ 4,736	$ 7,287
Tony Bagliore Concrete, Inc. (TBC) | Customer Relationships
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles acquired	$ 700
Acquired finite-lived intangible assets, useful life	7 years
Tony Bagliore Concrete, Inc. (TBC) | Contractual backlog
Finite-Lived Intangible Assets [Line Items]
Finite-lived intangibles acquired	$ 100
Acquired finite-lived intangible assets, useful life	7 months
TAS Commercial Concrete
Finite-Lived Intangible Assets [Line Items]
Amortization expense		$ 4,700
Reported Value Measurement [Member] | TAS Commercial Concrete | Trade Names
Finite-Lived Intangible Assets [Line Items]
Finite-lived Intangible Assets, Fair Value Disclosure				$ 6,900

Goodwill and Intangible Asset70

Goodwill and Intangible Assets - Future Amortization Expense of Finite-lived Intangible Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
2,016	$ 3,389
2,017	2,640
2,018	2,069
2,019	1,521
2,020	1,239
Thereafter	426
Net intangible assets, end of year	$ 11,284	$ 15,142

Goodwill and Intangible Asset71

Goodwill and Intangible Assets Goodwill (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016	Oct. 31, 2016	Dec. 31, 2015
Goodwill [Line Items]
Goodwill	$ 69,483	$ 66,351		$ 65,982
Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill	33,800
Commercial Concrete Segment
Goodwill [Line Items]
Goodwill	$ 35,700
Estimate of Fair Value Measurement | Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill impairment, segment value			$ 212,000
Estimate of Fair Value Measurement | Commercial Concrete Segment
Goodwill [Line Items]
Goodwill impairment, segment value			153,000
Reported Value Measurement | Heavy Civil Marine Construction Segment
Goodwill [Line Items]
Goodwill impairment, segment value			188,000
Reported Value Measurement | Commercial Concrete Segment
Goodwill [Line Items]
Goodwill impairment, segment value			$ 134,500

Goodwill and Intangible Asset72

Goodwill and Intangible Assets Intangible Assets (Details)	Oct. 31, 2016Rate
Heavy Civil Marine Construction Segment
Finite-Lived Intangible Assets [Line Items]
Discount rate	35.00%
Percentage off fair value in excess of carry amt	12.80%
Commercial Concrete Segment
Finite-Lived Intangible Assets [Line Items]
Discount rate	30.00%
Percentage off fair value in excess of carry amt	13.70%

Accrued Liabilities (Details)

Accrued Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Accrued Liabilities, Current [Abstract]
Accrued salaries, wages and benefits	$ 9,632	$ 10,818
Accrual for insurance liabilities	5,233	5,223
Property taxes	513	1,615
Sales taxes	1,836	1,722
Interest	46	19
Other accrued expenses	613	549
Total accrued liabilities	$ 17,873	$ 19,946

Long-term Debt and Line of Cr74

Long-term Debt and Line of Credit Narrative (Details) - USD ($)	3 Months Ended		12 Months Ended
	Sep. 30, 2017	Jun. 30, 2017	Dec. 31, 2017	Dec. 31, 2016	Aug. 05, 2015
Debt Instrument [Line Items]
Principal current			$ 23,500,000	$ 19,813,000
Principal			88,750,000	104,563,000
Deferred Finance Costs, current			(744,000)	(625,000)
Deferred Issuance Costs			(2,809,000)	(3,298,000)
Net Value, current			22,756,000	19,188,000
Long-term Debt, Excluding Current Maturities			63,185,000	82,077,000
Total debt			85,941,000	101,265,000
Hedging Liabilities, Noncurrent			26,000	382,000
Debt issuance cost			4,500,000
Debt issuance expense	$ 600,000	$ 200,000	$ 500,000
Line of Credit
Debt Instrument [Line Items]
Stated interest rate					4.75%
Debt, weighted average interest rate			3.80%
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Principal current			$ 10,000,000	8,000,000
Deferred Finance Costs, current			(317,000)	(252,000)
Net Value, current			$ 9,683,000	7,748,000
Line of credit facility, maximum borrowing capacity					$ 50,000,000
Stated interest rate			5.00%
Term Loan | Line of Credit
Debt Instrument [Line Items]
Total debt			$ 78,750,000
Line of credit facility, maximum borrowing capacity			135,000,000		$ 135,000,000
Term loan-current | Loans Payable
Debt Instrument [Line Items]
Principal current			13,500,000	11,813,000
Deferred Finance Costs, current			(427,000)	(373,000)
Net Value, current			13,073,000	11,440,000
Term loan-long-term | Loans Payable
Debt Instrument [Line Items]
Principal, long-term			65,250,000	84,750,000
Deferred Issuance Costs, long-term			(2,065,000)	(2,673,000)
Long-term Debt, Excluding Current Maturities			63,185,000	82,077,000
Long-term Debt | Accounting Standards Update 2015-03
Debt Instrument [Line Items]
Deferred Issuance Costs			(2,100,000)	(2,700,000)
Short-term Debt | Accounting Standards Update 2015-03
Debt Instrument [Line Items]
Deferred Issuance Costs			$ (700,000)	$ (600,000)

Long-term Debt and Line of Cr75

Long-term Debt and Line of Credit - Provisions of the Revolving Line of Credit and Accordion (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 05, 2015
Debt Instrument [Line Items]
Repayments of debt		$ 87,813,000	$ 63,084,000	$ 42,955,000
Proceeds from lines of credit		72,000,000	$ 57,000,000	$ 149,021,000
Line of Credit
Debt Instrument [Line Items]
Stated interest rate					4.75%
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	$ 10,000,000	10,000,000
Remaining borrowing capacity	39,300,000	39,300,000
Repayments of debt	$ 70,000,000
Proceeds from lines of credit		$ 72,000,000
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 50,000,000
Minimum additional borrowing amount					1,000,000
Amount over minimum additional borrowing amount, integral multiples					250,000
Stated interest rate	5.00%	5.00%
Revolving Credit Facility | Letter of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					20,000,000
Letters of credit outstanding	$ 700,000	$ 700,000
Revolving Credit Facility | Bridge Loan
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					5,000,000
Minimum additional borrowing amount					250,000
Amount over minimum additional borrowing amount, integral multiples					$ 50,000

Long-term Debt and Line of Cr76

Long-term Debt and Line of Credit - Provisions of the Term Loan (Details) - USD ($)	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015	Aug. 05, 2015
Debt Instrument [Line Items]
Quarterly principal payments		$ 11,800,000
Repayments of Debt		87,813,000	$ 63,084,000	$ 42,955,000
Current portion of debt	$ 13,500,000	13,500,000
Non-current portion of debt	65,300,000	65,300,000
Term Loan | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	78,800,000	78,800,000
Repayments of Debt		6,000,000
Line of credit facility, maximum borrowing capacity	135,000,000	135,000,000			$ 135,000,000
Revolving Credit Facility
Debt Instrument [Line Items]
Line of credit facility, amount outstanding	10,000,000	$ 10,000,000
Repayments of Debt	$ 70,000,000
Revolving Credit Facility | Line of Credit
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity					$ 50,000,000
LIBOR | Term Loan | Line of Credit
Debt Instrument [Line Items]
Effective interest rate	5.13%	5.13%

Long-term Debt and Line of Cr77

Long-term Debt and Line of Credit - Debt Maturity Schedule (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Debt Instrument [Line Items]
Total debt	$ 85,941	$ 101,265
Term Loan | Line of Credit
Debt Instrument [Line Items]
2,018	13,500
2,019	15,188
2,020	50,062
Total debt	$ 78,750

Long-term Debt and Line of Cr78

Long-term Debt and Line of Credit - Financial Covenants (Details)	3 Months Ended								5 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2015	Aug. 05, 2015
Debt Disclosure [Abstract]
Debt instrument, covenant, fixed charge coverage ratio, maximum										1.25
Debt instrument, covenant, leverage ratio, maximum	3	3	2.75	2.75	3	3.25	3.75	4	3.25

Long-term Debt and Line of Cr79

Long-term Debt and Line of Credit - Debt Extinguishment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Debt Instrument [Line Items]
Extinguishment of debt	$ 0	$ 0	$ 32,427

Long-term Debt and Line of Cr80

Long-term Debt and Line of Credit - Derivative Financial Instruments (Details) $ in Thousands	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 16, 2015USD ($)contract
Debt Instrument [Line Items]
Percent of aggregate principal amount hedged			50.00%
Interest rate swap liability	$ 26	$ 382
Swap
Debt Instrument [Line Items]
Derivative, notional amount			$ 67,500
Derivative, number of instruments held (contract) | contract			5
Liability
Debt Instrument [Line Items]
Interest rate swap liability	100
Derivative, Fair Value, Net	100
Liability | Fair Value, Measurements, Recurring
Debt Instrument [Line Items]
Derivative, Fair Value, Net	38	447
Liability | Fair Value, Inputs, Level 2 | Fair Value, Measurements, Recurring
Debt Instrument [Line Items]
Derivative, Fair Value, Net	$ 38	$ 447

Purchase of Common Shares (Deta

Purchase of Common Shares (Details) - USD ($)	1 Months Ended	3 Months Ended
	Oct. 31, 2014	Jun. 30, 2016
Stock Repurchase Program [Abstract]
Stock repurchase program, authorized amount	$ 40,000,000
Stock repurchase program, expected duration	5 years
Stock repurchased during period, shares		350,000
Stock repurchased during period, average (USD per share)		$ 8.83

Income Taxes - Narrative (Deta

Income Taxes - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Operating Loss Carryforwards [Line Items]
Consolidated effective tax rate	109.70%	(77.50%)	23.80%
Federal statutory tax rate		35.00%	35.00%
Deferred tax liabilities, provisional income tax benefit	$ 5,900
Deferred tax liabilities, provisional income tax benefit (in usd per share)	$ 0.21
Valuation allowance	$ 3,942	$ 3,321
Alternative minimum tax credits, non-expiring	700
Balance at the end of year	1,614	0
Deferred tax assets, net, noncurrent		$ 2,000
State
Operating Loss Carryforwards [Line Items]
Net operating loss carryforward	5,700
Federal Tax Authority
Operating Loss Carryforwards [Line Items]
Alternative minimum tax credits, non-expiring	$ 1,200

Income Taxes - Components of I

Income Taxes - Components of Income Tax Expense (Benefit) by Jurisdiction and by Classification (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
U.S. Federal (a)
Current	$ (780)	$ 35	$ 3
Deferred	(3,986)	(1,093)	(3,768)
Total	(4,766)	(1,058)	(3,765)
State and local
Current	550	511	(60)
Deferred	(180)	1,519	883
Total	370	2,030	823
Foreign
Current	(145)	284	423
Deferred	0	325	0
Total	(145)	609	423
Total Income Taxes
Current	(375)	830	366
Deferred	(4,166)	751	(2,885)
Total	$ (4,541)	$ 1,581	$ (2,519)

Income Taxes - Effective Incom

Income Taxes - Effective Income Tax Expense (Benefit) Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Effective Income Tax Rate Reconciliation, Amount [Abstract]
Statutory amount (computed at 35%)	$ (1,449)	$ (714)	$ (3,703)
Re-measurement of deferred tax assets	(7,451)	0	0
Valuation allowance on foreign tax credits	1,514	0	0
State income tax, net of federal benefit	168	94	(709)
Permanent differences, other	505	99	43
Permanent differences, incentive stock options	447	224	298
True up to prior years	188	109	0
Valuation Allowance, Deferred Tax Asset, Increase (Decrease), Amount	(77)	1,769	1,552
Balance at the end of year	1,614	0
Total	$ (4,541)	$ 1,581	$ (2,519)
Consolidated effective tax rate	109.70%	(77.50%)	23.80%

Income Taxes - Components of D

Income Taxes - Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Current
Accrued liabilities	$ 0	$ 2,322
Deferred Tax Assets, Tax Deferred Expense, Reserves and Accruals, Accrued Liabilities	1,226
Intangible assets	0	0
Non-qualified stock options	0	112
Other	0	45
Total assets	0	2,479
Long- term (a)
Intangible assets	3,010	4,517
Net operating loss carryforward	6,912	7,455
Valuation allowance	(3,942)	(3,321)
Non-qualified stock options	762	1,367
Foreign tax credits	1,751	2,035
Deferred Tax Assets, Tax Credit Carryforwards	(1,514)
AMT credits	0	780
Other	215	16
Total assets	8,420	12,849
Current
Deferred revenue on maintenance contracts	0	(429)
Other	0	(37)
Total liabilities	0	(466)
Net current deferred tax assets	0	2,013
Long-term
Depreciation and amortization	(15,788)	(25,326)
Goodwill	(5,178)	(6,502)
Deferred revenue on maintenance contracts	(597)	0
Other	(100)	(21)
Total liabilities	(21,663)	(31,849)
Net non-current deferred tax liabilities	$ (13,243)	$ (19,000)

Income Taxes - Summary of Defe

Income Taxes - Summary of Deferred Tax Asset and Liabilities, as Reported in the Balance Sheet (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Summary of Deferred Tax Assets and Liabilities, as Reported in the Balance Sheet [Abstract]
Net current deferred tax assets	$ 0	$ 2,013
Net non-current deferred tax liabilities	(13,243)	(19,000)
Total net deferred tax liabilities:	$ (13,243)	$ (16,987)

Income Taxes -Unrecognized Tax

Income Taxes -Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Additions based on tax positions related to prior years	$ 1,614
Balance at the end of year	$ 1,614	$ 0

Earnings (Loss) Per Share - Ba

Earnings (Loss) Per Share - Basic and Diluted (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Basic:
Weighted average shares outstanding	28,029,936	27,536,967	27,366,528
Effect of dilutive securities:
Common stock options	324,344	0	0
Total weighted average shares outstanding assuming dilution	28,354,280	27,536,967	27,366,528
Shares of common stock issued from the exercise of stock options	229,551	13,850	3,970

Earnings (Loss) Per Share - An

Earnings (Loss) Per Share - Antidilutive Securities (Details) - shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Potential antidilutive securities excluded from future computations (in shares)	2,274,908	2,381,926	2,043,375
Stock options
Antidilutive Securities Excluded from Computation of Earnings Per Share [Line Items]
Anti-dilutive stock options	0	0	0

Stock-Based Compensation - Nar

Stock-Based Compensation - Narrative (Details) - USD ($) $ / shares in Units, $ in Thousands	1 Months Ended					12 Months Ended
	May 31, 2017	May 31, 2016	Sep. 30, 2015	Nov. 30, 2014	May 31, 2011	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Approved and authorized maximum number of shares to be issued	2,400,000
Share-based Compensation Arrangements by Share-based Payment Award, Options, Grants in Period, Weighted Average Exercise Price						$ 7.22	$ 4.98	$ 5.82
Compensation expense related to stock based awards outstanding						$ 2,300
Granted (in shares)						425,204	587,862	143,862
Proceeds received upon exercise of stock options						$ 1,300	$ 67	$ 28
Exercise of stock options, shares						229,551	13,850	3,970
Total share-based compensation cost not yet recognized						$ 2,900
Share-based compensation cost not yet recognized, period for recognition						2 years
Total intrinsic value of options exercised						$ 706	$ 53	$ 17
Total fair value of shares vested						$ 855	$ 986	$ 1,226
Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, expiration period					10 years
Forfeiture rate applied to options						5.50%
Stock options | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants awarded during period (in shares)	12,465	14,170
Weighted average grant-date fair value of options granted (in USD per share)	$ 7.22
Stock options | Officers and Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, vesting period				3 years			3 years
Weighted average grant-date fair value of options granted (in USD per share)	$ 7.22	$ 4.96		$ 4.98
Granted (in shares)	213,643	267,175					587,862
Stock options | Directors, Officers and Executives
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants awarded during period (in shares)						0
Stock options | Chief Operating Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Grants awarded during period (in shares)			38,660
Weighted average grant-date fair value of options granted (in USD per share)			$ 5.82
Granted (in shares)			143,862
Stock options | Minimum
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options, vesting period					3 years
Performance Shares | Director
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant-date fair value of options granted (in USD per share)		$ 4.94
Performance Shares | Executive Officer
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Performance awards granted in period	69,945	68,977
Performance period	2 years	2 years
Weighted average grant-date fair value of options granted (in USD per share)	$ 7.22
2017 LTIP | Stock options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Forfeiture rate applied to options						3.20%

Stock-Based Compensation - Res

Stock-Based Compensation - Restricted Stock Activity (Details) - Restricted stock - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Beginning nonvested shares (in shares)	372,306	120,154	235,863
Granted (in shares)	345,913	407,002	38,660
Vested (in shares)	(225,406)	(147,259)	(134,545)
Forfeited/repurchased shares (in shares)	(120,353)	(7,591)	(19,824)
Ending nonvested shares (in shares)	372,460	372,306	120,154
Weighted Average Fair Value Per Share
Beginning nonvested shares (in dollars per share)	$ 5.66	$ 9.28	$ 8.63
Granted (in dollars per share)	7.22	4.96	5.82
Vested (in dollars per share)	7.25	6.62	6.84
Forfeited/repurchased shares (in dollars per share)	6.08	7.08	11.35
Ending nonvested shares (in dollars per share)	$ 6.01	$ 5.66	$ 9.28

Stock-Based Compensation - Sto

Stock-Based Compensation - Stock Option Activity (Details) - USD ($) $ / shares in Units, $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Number of Shares
Beginning stock options outstanding (in shares)	2,349,446	2,149,900	2,056,898
Granted (in shares)	425,204	587,862	143,862
Exercised (in shares)	(229,551)	(13,850)	(3,970)
Forfeited (in shares)	(633,978)	(374,466)	(46,890)
Ending stock options outstanding (in shares)	1,911,121	2,349,446	2,149,900
Weighted Average Exercise Price Per Share
Beginning stock options outstanding (in dollars per share)	$ 8.39	$ 9.56	$ 9.86
Granted (in dollars per share)	7.22	4.98	5.82
Exercised (in dollars per share)	5.75	4.86	6
Forfeited (in dollars per share)	10.36	9.89	11.72
Ending stock options outstanding (in dollars per share)	$ 7.79	$ 8.39	$ 9.56
Vested and expected to vest at December 31, 2017
Number of Shares	2,024,130
Weighted Average Exercise Price Per Share (in dollars per share)	$ 7.69
Weighted Average Contractual Life	5 years 3 months 4 days
Aggregate Intrinsic Value	$ 2,872
December 31, 2017
Number of Shares	1,462,481
Weighted Average Exercise Price Per Share (in dollars per share)	$ 8.18
Weighted Average Contractual Life	3 years 9 months 26 days
Aggregate Intrinsic Value	$ 2,054

Stock-Based Compensation - S93

Stock-Based Compensation - Stock Option Valuation Assumptions (Details) - Stock Option - $ / shares	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Fair Value Assumptions and Methodology [Abstract]
Weighted average grant-date fair value of options granted (in USD per share)	$ 7.22	$ 4.97	$ 5.82
Risk-free interest rate	1.46%	1.06%	0.97%
Expected volatility	48.00%	49.00%	38.00%
Expected term of options	3 years	3 years	3 years
Dividend yield	0.00%	0.00%	0.00%

Employee Benefits - Narrative

Employee Benefits - Narrative (Details) - USD ($) $ in Millions	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
401 (k) Retirement Plan [Abstract]
Minimum service period for plan eligibility	6 months
Minimum allowable contribution to the plan by each employee, percent	1.00%
Maximum allowable contribution to the plan by each employee, percent	80.00%
Employers matching contribution, vesting period	4 years
Company contributions to the plan	$ 1.4
Range 1
401 (k) Retirement Plan [Abstract]
Employer matching contribution, percent	100.00%
Employer matching contribution, percent of employees' gross pay	2.00%
Range 2
401 (k) Retirement Plan [Abstract]
Employer matching contribution, percent	50.00%
Employer matching contribution, percent of employees' gross pay	2.00%
AGC Southwest Chapters 401(k) Retirement Plan
401 (k) Retirement Plan [Abstract]
Employer matching contribution, percent	50.00%
Employers matching contribution, vesting period	5 years
Employer matching contribution, percent of employees' gross pay	6.00%
Employer discretionary contribution amount	$ 0.4	$ 0.2	$ 0.1

Employee Benefits - Multiemplo

Employee Benefits - Multiemployer Plans (Details) - Multiemployer Plans, Pension - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
International Union of Operating Engineers - Employers Construction Industry Retirement Plan - Local 302 and 612 Trust Funds
Multiemployer Plans [Line Items]
Certified Zone Status	[1]	Green	Green
Contributions		$ 1,974	$ 2,158	$ 1,518
Expiration of Collective Bargaining Agreement		Dec. 31, 2018
Associated General Contractors of Washington Carpenter, Piledrivers, and Millwrights
Multiemployer Plans [Line Items]
Certified Zone Status	[1]	Green	Green
Contributions		$ 693	$ 938	748
Expiration of Collective Bargaining Agreement		Dec. 31, 2018
Alaska Carpenters Trust Fund
Multiemployer Plans [Line Items]
Certified Zone Status	[1]	Green	Green
Contributions		$ 396	$ 889	807
Expiration of Collective Bargaining Agreement		Jun. 30, 2020
Alaska Laborers Trust Fund
Multiemployer Plans [Line Items]
Certified Zone Status	[1]	Yellow	Yellow
Contributions		$ 218	$ 126	$ 110
Expiration of Collective Bargaining Agreement		Dec. 31, 2017
[1]	The most recent PPA zone status available in 2017 and 2016 is for the plan's year end during 2016 and 2015, respectively. Zone status is based on information received from the plan and is indicative of the plans funding status. Among other factors, plans in the red zone are generally less than 65 percent funded, plans in the orange zone are less than 80 percent funded and have an Accumulated Funding Deficiency in the current year or projected into the next six years, plans in the yellow zone are less than 80 percent funded, and plans in the green zone are at least 80 percent funded.

Commitments and Contingencies

Commitments and Contingencies - Narrative (Details) $ in Thousands	1 Months Ended	12 Months Ended
	Jul. 31, 2005USD ($)extension	Dec. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Dec. 31, 2015USD ($)
Sale Leaseback Transaction [Abstract]
Rent expense			$ 85	$ 173
Operating Leases, Rent Expense, Net [Abstract]
Operating leases, rent expense		$ 1,700	1,000
Office building
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		9 years
Vehicles
Operating Leases, Rent Expense, Net [Abstract]
Operating leases, rent expense		$ 700	$ 1,500	2,300
Other facilities | Minimum
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		1 year
Other facilities | Maximum
Operating Leases, Rent Expense, Net [Abstract]
Lease term of assets subject to operating leases		5 years
Office building
Sale Leaseback Transaction [Abstract]
Proceeds from the sale-leaseback transaction	$ 2,100
Sale-leaseback term	10 years
Deferred gain on sale-leaseback transaction	$ 562
Gain recognized on sale-lease back transaction		$ 8		$ 56
Options to extend term of the lease for additional five years | extension	2
Maximum extension term of each option to extend	5 years

Commitments and Contingencies97

Commitments and Contingencies - Operating Leases Future Minimum Payments (Details) $ in Thousands	Dec. 31, 2017USD ($)
Operating Leases, Future Minimum Payments Due, Fiscal Year Maturity [Abstract]
2,018	$ 7,371
2,019	6,560
2,020	5,364
2,021	3,247
2,022	1,824
Thereafter	12,947
Total	$ 37,313

Segment Information (Details)

Segment Information (Details)	3 Months Ended								6 Months Ended	12 Months Ended
	Dec. 31, 2017USD ($)	Sep. 30, 2017USD ($)	Jun. 30, 2017USD ($)	Mar. 31, 2017USD ($)	Dec. 31, 2016USD ($)	Sep. 30, 2016USD ($)	Jun. 30, 2016USD ($)	Mar. 31, 2016USD ($)	Dec. 31, 2015segment	Dec. 31, 2017USD ($)segment	Dec. 31, 2016USD ($)segment	Dec. 31, 2015USD ($)
Segment Reporting Information [Line Items]
Contract revenues	$ 162,214,000	$ 140,162,000	$ 137,420,000	$ 138,757,000	$ 144,295,000	$ 164,017,000	$ 140,301,000	$ 129,623,000		$ 578,553,000	$ 578,236,000	$ 466,498,000
Number of reportable segments | segment									2	2	2
Intersegment Eliminations
Segment Reporting Information [Line Items]
Contract revenues										$ 0	$ 0
Heavy Civil Marine Construction Segment | Mexico and the Caribbean
Segment Reporting Information [Line Items]
Contract revenues										$ 9,400,000	$ 7,400,000

Segment Information - Summary (

Segment Information - Summary (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Segment Reporting Information [Line Items]
Contract revenues	$ 162,214	$ 140,162	$ 137,420	$ 138,757	$ 144,295	$ 164,017	$ 140,301	$ 129,623	$ 578,553	$ 578,236	$ 466,498
Operating income (loss)	10,840	$ (5,354)	$ (2,466)	$ (1,482)	(5,283)	$ 9,531	$ 281	$ (455)	1,538	4,074	(7,999)
Depreciation and amortization									(29,491)	(34,162)	$ (28,083)
Assets	433,285				447,676				433,285	447,676
Property and equipment, net	146,278				158,082				146,278	158,082
Operating Segments | Heavy Civil Marine Construction Segment
Segment Reporting Information [Line Items]
Contract revenues									285,736	284,632
Operating income (loss)									(18,406)	(12,403)
Depreciation and amortization									(20,370)	(21,398)
Assets	260,935				279,362				260,935	279,362
Property and equipment, net	128,421				143,425				128,421	143,425
Operating Segments | Commercial Concrete Segment
Segment Reporting Information [Line Items]
Contract revenues									292,817	293,604
Operating income (loss)									19,944	16,477
Depreciation and amortization									(9,121)	(12,764)
Assets	172,350				168,314				172,350	168,314
Property and equipment, net	$ 17,857				$ 14,657				$ 17,857	$ 14,657

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Aug. 05, 2015
Related Party Transaction [Line Items]
Operating leases, rent expense	$ 1,700	$ 1,000
GLM Concrete Solutions, LLC
Related Party Transaction [Line Items]
Issued and outstanding membership interest acquired			49.00%
Affiliated Entity | Lease Arrangement
Related Party Transaction [Line Items]
Operating leases, annual lease amount	$ 478
Operating leases, rent expense		$ 820

Selected Quarterly Financial101

Selected Quarterly Financial Data (Details) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income tax expense									$ (4,541)	$ 1,581	$ (2,519)
Selected Quarterly Financial Information [Abstract]
Revenues	$ 162,214	$ 140,162	$ 137,420	$ 138,757	$ 144,295	$ 164,017	$ 140,301	$ 129,623	578,553	578,236	466,498
Gross profit	27,751	10,757	15,397	12,985	11,657	24,169	16,946	14,710	66,890	67,482	40,182
Operating (loss) income	10,840	(5,354)	(2,466)	(1,482)	(5,283)	9,531	281	(455)	1,538	4,074	(7,999)
(Loss) income before income taxes	9,306	(6,703)	(3,917)	(2,827)	(6,734)	7,963	(1,310)	(1,958)	(4,141)	(2,039)	$ (10,579)
Net (loss) income	$ 9,538	$ (5,037)	$ (2,293)	$ (1,808)	$ (6,343)	$ 4,739	$ (808)	$ (1,208)	$ 400	$ (3,620)
Earnings Per Share, Basic and Diluted [Abstract]
Basic (USD per share)	$ 0.34	$ (0.18)	$ (0.08)	$ (0.07)	$ (0.23)	$ 0.17	$ (0.03)	$ (0.04)	$ 0.01	$ (0.13)	$ (0.29)
Diluted income (loss) per share (USD per share)	$ 0.34	$ (0.18)	$ (0.08)	$ (0.07)	$ (0.23)	$ 0.17	$ (0.03)	$ (0.04)	$ 0.01	$ (0.13)	$ (0.29)
Restatement Adjustment
Income tax expense	$ 800

Schedule II - Valuation and 102

Schedule II - Valuation and Qualifying Accounts (Details) - Allowance for doubtful accounts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Activity in Provision for Doubtful Accounts
Balance at the Beginning of the Period	$ 0	$ 0	$ 0
Charged to Revenue, Cost or Expense	0	0	22
Deduction	0	0	(22)
Balance at the End of the Period	$ 0	$ 0	$ 0