Great Lakes Dredge & Dock (GLDD) 10-K 26 Feb 20 2019 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2019	Feb. 21, 2020	Jun. 28, 2019
Cover [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	FY
Trading Symbol	GLDD
Entity Registrant Name	Great Lakes Dredge & Dock CORP
Entity Central Index Key	0001372020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Shell Company	false
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Address, Address Line One	2122 York Road
Entity Address, City or Town	Oak Brook
Entity Address, State or Province	IL
Entity File Number	001-33225
Entity Tax Identification Number	20-5336063
City Area Code	630
Local Phone Number	574-3000
Entity Address, Postal Zip Code	60523
Entity Interactive Data Current	Yes
Title of 12(b) Security	Common Stock, (Par Value $0.0001)
Security Exchange Name	NASDAQ
Entity Incorporation, State or Country Code	DE
Document Annual Report	true
Document Transition Report	false
Entity Common Stock, Shares Outstanding		64,285,602
Entity Public Float			$ 689,871,174
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes
Documents Incorporated by Reference	DOCUMENTS INCORPORATED BY REFERENCE Part of 10-K Documents Incorporated by Reference Part III Portions of the Proxy Statement to be filed with the Securities and Exchange Commission in connection with the 2020 Annual Meeting of Stockholders.

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($)	Dec. 31, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 186,995,000	$ 34,458,000
Accounts receivable—net	19,785,000	64,779,000
Contract revenues in excess of billings	22,560,000	17,953,000
Inventories	30,189,000	28,112,000
Prepaid expenses	1,525,000	4,710,000
Other current assets	39,658,000	31,907,000
Assets held for sale		24,779,000
Total current assets	300,712,000	206,698,000
PROPERTY AND EQUIPMENT—Net	374,596,000	369,863,000
OPERATING LEASE ASSETS	72,612,000
GOODWILL	76,576,000	76,576,000
INVENTORIES—Noncurrent	61,126,000	61,264,000
ASSETS HELD FOR SALE— Noncurrent	3,970,000	5,110,000
OTHER	7,960,000	10,760,000
TOTAL	897,552,000	730,271,000
LIABILITIES AND EQUITY
Accounts payable	76,091,000	71,537,000
Accrued expenses	51,225,000	48,351,000
Operating lease liabilities	21,351,000
Billings in excess of contract revenues	55,266,000	17,793,000
Revolving credit facility	0	11,500,000
Liabilities held for sale		13,940,000
Total current liabilities	203,933,000	163,121,000
LONG-TERM DEBT	322,843,000	321,950,000
OPERATING LEASE LIABILITIES—Noncurrent	51,131,000
DEFERRED INCOME TAXES	35,740,000	22,846,000
LIABILITIES HELD FOR SALE— Noncurrent		146,000
OTHER	4,506,000	7,280,000
Total liabilities	618,153,000	515,343,000
COMMITMENTS AND CONTINGENCIES (Note 13)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 64,283 and 62,830 shares issued; 64,283 and 62,552 outstanding at December 31, 2019 and December 31, 2018, respectively.	6,000	6,000
Treasury stock, at cost		(1,433,000)
Additional paid-in capital	302,189,000	295,135,000
Accumulated deficit	(23,091,000)	(74,971,000)
Accumulated other comprehensive income (loss)	295,000	(3,809,000)
Total equity	279,399,000	214,928,000
TOTAL	$ 897,552,000	$ 730,271,000

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par value	$ 0.0001	$ 0.0001
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares issued	64,283,000	62,830,000
Common stock, shares outstanding	64,283,000	62,552,000

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Statement [Abstract]
CONTRACT REVENUES	$ 711,518	$ 620,795	$ 592,159
Type of Revenue [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
COSTS OF CONTRACT REVENUES	$ 557,761	$ 509,335	$ 549,429
Type of Cost, Good or Service [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
GROSS PROFIT	$ 153,757	$ 111,460	$ 42,730
OPERATING EXPENSES:
GENERAL AND ADMINISTRATIVE EXPENSES	59,110	55,108	57,235
PROCEEDS FROM LOSS OF USE CLAIM	(4,619)
LOSS ON SALE OF ASSETS—Net	1,138	3,731	4,789
Total operating income (loss)	98,128	52,621	(19,294)
OTHER EXPENSE:
Interest expense—net	(27,524)	(33,578)	(28,362)
Equity in loss of joint ventures			(1,484)
Other income (expense)	317	(2,590)	11
Total other expense	(27,207)	(36,168)	(29,835)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	70,921	16,453	(49,129)
INCOME TAX (PROVISION) BENEFIT	(15,253)	(5,437)	33,761
INCOME (LOSS) FROM CONTINUING OPERATIONS	55,668	11,016	(15,368)
Loss from discontinued operations, net of income taxes	(6,329)	(17,309)	(15,892)
NET INCOME (LOSS)	$ 49,339	$ (6,293)	$ (31,260)
Basic earnings (loss) per share attributable to income (loss) from continuing operations	$ 0.88	$ 0.18	$ (0.25)
Basic loss per share attributable to loss on discontinued operations, net of income taxes	(0.10)	(0.28)	(0.26)
Basic earnings (loss) per share	$ 0.78	$ (0.10)	$ (0.51)
Basic weighted average shares	63,597	62,236	61,365
Diluted earnings (loss) per share attributable to income (loss) from continuing operations	$ 0.86	$ 0.17	$ (0.25)
Diluted loss per share attributable to loss on discontinued operations, net of income taxes	(0.10)	(0.27)	(0.26)
Diluted earnings (loss) per share	$ 0.76	$ (0.10)	$ (0.51)
Diluted weighted average shares	65,042	63,607	61,365

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)		$ 49,339	$ (6,293)	$ (31,260)
Currency translation adjustment—net of tax	[1]		1,513	(41)
Net unrealized (gain) loss on derivatives—net of tax	[2]	4,104	(5,325)	1,189
Other comprehensive income (loss)—net of tax		4,104	(3,812)	1,148
Comprehensive income (loss)		$ 53,443	$ (10,105)	$ (30,112)
[1]	Net of income tax (provision) benefit of $(1,017) and $44 for the years ended December 31, 2018 and 2017, respectively.
[2]	Net of income tax (provision) benefit of $(421), $775 and $1,048 for the years ended December 31, 2019, 2018 and 2017, respectively.

Consolidated Statements of Co_2

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Statement Of Income And Comprehensive Income [Abstract]
Currency translation adjustment, tax		$ (1,017)	$ 44
Net unrealized loss on derivatives, tax	$ (421)	$ 775	$ 1,048

Consolidated Statements of Equi

Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
BALANCE - value at Dec. 31, 2016	$ 247,890	$ 6	$ (1,433)	$ 286,303	$ (35,841)	$ (1,145)
BALANCE - shares at Dec. 31, 2016		61,240	(278)
Share-based compensation, value	2,963			2,963
Share-based compensation, shares		248
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(328)			(328)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		147
Exercise of stock options and purchases from employee stock purchase plan, value	883			883
Exercise of stock options and purchases from employee stock purchase plan, shares		262
Net income (loss)	(31,260)				(31,260)
Other comprehensive income (loss)-net of tax	1,148					1,148
BALANCE - value at Dec. 31, 2017	221,296	$ 6	$ (1,433)	289,821	(67,101)	3
BALANCE - shares at Dec. 31, 2017		61,897	(278)
Cumulative effect of recent accounting pronouncements	(1,577)				(1,577)
Share-based compensation, value	5,425			5,425
Share-based compensation, shares		132
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(1,205)			(1,205)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		520
Exercise of stock options and purchases from employee stock purchase plan, value	1,094			1,094
Exercise of stock options and purchases from employee stock purchase plan, shares		281
Net income (loss)	(6,293)				(6,293)
Other comprehensive income (loss)-net of tax	(3,812)					(3,812)
BALANCE - value at Dec. 31, 2018	214,928	$ 6	$ (1,433)	295,135	(74,971)	(3,809)
BALANCE - shares at Dec. 31, 2018		62,830	(278)
Cumulative effect of recent accounting pronouncements	2,802				2,802
Share-based compensation, value	8,395			8,395
Share-based compensation, shares		73
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(5,008)			(5,008)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		873
Exercise of stock options and purchases from employee stock purchase plan, value	$ 4,839			4,839
Exercise of stock options and purchases from employee stock purchase plan, shares	650	785
Cancellation of treasury stock			$ 1,433	(1,172)	(261)
Cancellation of treasury stock, share		(278)	278
Net income (loss)	$ 49,339				49,339
Other comprehensive income (loss)-net of tax	4,104					4,104
BALANCE - value at Dec. 31, 2019	$ 279,399	$ 6		$ 302,189	$ (23,091)	$ 295
BALANCE - shares at Dec. 31, 2019		64,283

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
OPERATING ACTIVITIES:
Net income (loss)	$ 49,339	$ (6,293)	$ (31,260)
Loss from discontinued operations, net of income taxes	(6,329)	(17,309)	(15,892)
INCOME (LOSS) FROM CONTINUING OPERATIONS	55,668	11,016	(15,368)
Adjustments to reconcile net income (loss) to net cash flows provided by operating activities:
Depreciation and amortization	37,145	50,389	55,962
Equity in loss of joint ventures			1,484
Loss on extinguishment of 7 3/8% senior subordinated notes			2,330
Cash distributions from joint ventures			340
Deferred income taxes	15,134	5,760	(32,836)
Loss on dispositions of property and equipment	1,138	3,731	4,789
Other non-cash restructuring items		2,337	15,678
Amortization of deferred financing fees	2,746	3,504	3,280
Unrealized foreign currency gain		(231)	(206)
Unrealized net loss from mark-to-market valuations of derivatives			1,747
Share-based compensation expense	6,908	4,643	2,917
Changes in assets and liabilities:
Accounts receivable	44,994	(8,364)	5,354
Contract revenues in excess of billings	(4,607)	54,881	10,939
Inventories	(1,939)	(921)	(2,163)
Prepaid expenses and other current assets	(8,539)	11,976	(1,868)
Accounts payable and accrued expenses	12,546	(1,480)	(16,179)
Billings in excess of contract revenues	37,473	7,524	(567)
Other noncurrent assets and liabilities	3,120	(3,093)	(1,658)
Net cash flows provided by operating activities of continuing operations	201,787	141,672	33,975
Net cash flows used in operating activities of discontinued operations	(9,238)	(4,019)	(12,457)
Cash provided by operating activities	192,549	137,653	21,518
INVESTING ACTIVITIES:
Purchases of property and equipment	(49,412)	(49,422)	(65,996)
Proceeds from dispositions of property and equipment	5,592	13,880	8,586
Net cash flows used in investing activities of continuing operations	(43,820)	(35,542)	(57,410)
Net cash flows (used in) provided by investing activities of discontinued operations	18,056	425	(742)
Cash used in investing activities	(25,764)	(35,117)	(58,152)
FINANCING ACTIVITIES:
Proceeds from issuance of debt			325,000
Repayments of debt		(298)	(276,148)
7 3/8% senior notes tender premium			(744)
Deferred financing fees	(2,388)		(5,022)
Taxes paid on settlement of vested share awards	(5,008)	(1,205)	(328)
Exercise of stock options and purchases from employee stock plans	4,839	1,094	883
Borrowings under revolving loans		29,000	124,925
Repayments of revolving loans	(11,500)	(112,500)	(134,036)
Net cash flows (used in) provided by financing activities of continuing operations	(14,057)	(83,909)	34,530
Net cash flows used in financing activities of discontinued operations	(191)	(1,547)	(361)
Cash (used in) provided by financing activities	(14,248)	(85,456)	34,169
Effect of foreign currency exchange rates on cash and cash equivalents		26	115
Net increase (decrease) in cash, cash equivalents and restricted cash	152,537	17,106	(2,350)
Cash, cash equivalents and restricted cash at beginning of period	34,458	17,352	19,702
Cash, cash equivalents and restricted cash at end of period	186,995	34,458	17,352
Cash and cash equivalents	186,995	34,458	15,852
Restricted cash included in other long-term assets			1,500
Cash, cash equivalents and restricted cash at end of period	186,995	34,458	17,352
Supplemental Cash Flow Information
Cash paid for interest	24,942	30,855	34,789
Cash paid for income taxes	366	290	365
Non-cash Investing and Financing Activities
Property and equipment purchased but not yet paid	$ 6,473	7,303	$ 4,255
Repayments of debt with proceeds from sale-leaseback transactions		$ 13,034

Consolidated Statements of Ca_2

Consolidated Statements of Cash Flows (Parenthetical)	Dec. 31, 2019	Dec. 31, 2018	May 31, 2017
7 3/8% SENIOR NOTES [Member]
Debt instrument, interest rate, stated percentage	7.375%	7.375%	7.375%

Nature of Business and Summary

Nature of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature of Business and Summary of Significant Accounting Policies	1. NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization —Great Lakes Dredge & Dock Corporation and its subsidiaries (the “Company” or “Great Lakes”) are in the business of marine construction, primarily dredging. The Company’s primary customers are domestic and foreign government agencies, as well as private entities. Principles of Consolidation and Basis of Presentation —The consolidated financial statements include the accounts of Great Lakes Dredge & Dock Corporation and its majority-owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation. The equity method of accounting is used for investments in unconsolidated investees in which the Company has significant influence, but not control. Other investments, if any, are carried at cost. Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect certain reported amounts and disclosures. Accordingly, actual results could differ from those estimates. Revenue and Cost Recognition on Contracts — Prior to January 1, 2018, the Company measured completion based on engineering estimates of the physical percentage completed for dredging contracts. Under the new accounting principle, revenue is recognized using contract fulfillment costs incurred to date compared to total estimated costs at completion, also known as cost-to-cost, to measure progress towards completion. Additionally, the Company capitalizes certain pre-contract and pre-construction costs, and defers recognition over the life of the contract. Fixed-price contracts, which comprise substantially all of the Company’s revenue, will most often represent a single performance obligation as the promise to transfer the individual services is not separately identifiable from other promises in the contracts and, therefore, not distinct. The Company’s performance obligations are satisfied over time and revenue is recognized using the cost-to-cost method, described above. Contract modifications are changes in the scope or price (or both) of a contract that are approved by the parties to the contract. The Company recognizes a contract modification when the parties to a contract approve a modification that either creates new, or changes existing, enforceable rights and obligations of the parties to the contract. Contract modifications are included in the transaction price only if it is probable that the modification estimate will not result in a significant reversal of revenue. Revisions in estimated gross profit percentages are recorded in the period during which the change in circumstances is experienced or becomes known. As the duration of most of the Company’s contracts is one year or less, the cumulative net impact of these revisions in estimates, individually and in the aggregate across projects, does not significantly affect results across annual reporting periods. Provisions for estimated losses on contracts in progress are made in the period in which such losses are determined. The components of costs of contract revenues include labor, equipment (including depreciation, maintenance, insurance and long-term rentals), subcontracts, fuel, supplies, short-term rentals and project overhead. Hourly labor generally is hired on a project-by-project basis. The Company is a party to numerous collective bargaining agreements in the U.S. that govern its relationships with its unionized hourly workforce. 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, unless completion of such contracts extends significantly beyond one year. Cash Equivalents —The Company considers all highly liquid investments with a maturity at purchase of three months or less to be cash equivalents. Accounts Receivable —Accounts receivable represent amounts due or billable under the terms of contracts with customers, including amounts related to retainage. The Company anticipates collection of retainage generally within one year, and accordingly presents retainage as a current asset. The Company provides an allowance for estimated uncollectible accounts receivable when events or conditions indicate that amounts outstanding are not recoverable. Inventories —Inventories consist of pipe and spare parts used in the Company’s dredging operations. Pipe and spare parts are purchased in large quantities; therefore, a certain amount of pipe and spare part inventories is not anticipated to be used within the current year and is classified as long-term. Spare part inventories are stated at weighted average historical cost, and are charged to expense when used in operations. Pipe inventory is recorded at cost and amortized to expense over the period of its use. Property and Equipment —Capital additions, improvements, and major renewals are classified as property and equipment and are carried at depreciated cost. Maintenance and repairs that do not significantly extend the useful lives of the assets or enhance the capabilities of such assets are charged to expenses as incurred. Depreciation is recorded over the estimated useful lives of property and equipment using the straight-line method and the mid-year depreciation convention. The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30 Leasehold improvements are amortized over the shorter of their remaining useful lives or the remaining terms of the leases. Goodwill and Other Intangible Assets —Goodwill represents the excess of acquisition cost over fair value of the net assets acquired. Other identifiable intangible assets may represent developed technology and databases, customer relationships, and customer contracts acquired in business combinations. Goodwill is tested annually for impairment in the third quarter of each year, or more frequently should circumstances dictate. GAAP requires that goodwill of a reporting unit be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company assesses the fair values of its reporting unit using both a market-based approach and an income-based approach. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows. The income approach is dependent on a number of factors, including estimates of future market growth trends, forecasted revenues and expenses, appropriate discount rates and other variables. The estimates are based on assumptions that the Company believes to be reasonable, but such assumptions are subject to unpredictability and uncertainty. Changes in these estimates and assumptions could materially affect the determination of fair value, and may result in the impairment of goodwill in the event that actual results differ from those estimates. The market approach measures the value of a reporting unit through comparison to comparable companies. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA. The Company analyzes companies that performed similar services or are considered peers. Due to the fact that there are no public companies that are direct competitors, the Company weighs the results of this approach less than the income approach. The Company has one operating segment which is also the Company’s one reportable segment and reporting unit of which the Company tests goodwill for impairment. The historical environmental & infrastructure segment, which the Company sold during the second quarter of 2019, has been retrospectively presented as discontinued operations and assets and liabilities held for sale and is no longer reflected in continuing operations. The Company performed its most recent annual test of impairment as of July 1, 2019 with no indication of impairment as of the test date. The Company will perform its next scheduled annual test of goodwill in the third quarter of 2020 should no triggering events occur which would require a test prior to the next annual test. Long-Lived Assets —Long-lived assets are comprised of property and equipment and intangible assets subject to amortization. Long-lived assets to be held and used are reviewed for possible impairment whenever events indicate that the carrying amount of such assets may not be recoverable by comparing the undiscounted cash flows associated with the assets to their carrying amounts. If such a review indicates an impairment, the carrying amount would be reduced to fair value. No triggering events were identified in 2019 or 2018. If long-lived assets are to be disposed, depreciation is discontinued, if applicable, and the assets are reclassified as held for sale at the lower of their carrying amounts or fair values less estimated costs to sell. Self-insurance Reserves —The Company self-insures costs associated with its seagoing employees covered by the provisions of Jones Act, workers’ compensation claims, hull and equipment liability, and general business liabilities up to certain limits. Insurance reserves are established for estimates of the loss that the Company may ultimately incur on reported claims, as well as estimates of claims that have been incurred but not yet reported. In determining its estimates, the Company considers historical loss experience and judgments about the present and expected levels of cost per claim. Trends in actual experience are a significant factor in the determination of such reserves. Income Taxes —The provision for income taxes includes federal, foreign, and state income taxes currently payable and those deferred because of temporary differences between the financial statement and tax basis of assets and liabilities. Recorded deferred income tax assets and liabilities are based on the estimated future tax effects of differences between the financial and tax basis of assets and liabilities, given the effect of currently enacted tax laws. In 2017, the U.S. government enacted comprehensive tax legislation referred to as the Tax Cuts and Jobs Act. Refer to Note 8, Income Taxes. Hedging Instruments —At times, the Company designates certain derivative contracts as a cash flow hedge as defined by GAAP. Accordingly, the Company formally documents, at the inception of each hedge, all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking hedge transactions. This process includes linking all derivatives to highly-probable forecasted transactions. The Company formally assesses, at inception and on an ongoing basis, the effectiveness of hedges in offsetting changes in the cash flows of hedged items. Hedge accounting treatment may be discontinued when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the cash flows of a hedged item (including hedged items for forecasted future transactions), (2) the derivative expires or is sold, terminated or exercised, (3) it is no longer probable that the forecasted transaction will occur or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate. If management elects to stop hedge accounting, it would be on a prospective basis and any hedges in place would be recognized in accumulated other comprehensive income (loss) until all the related forecasted transactions are completed or are probable of not occurring. Foreign Currency Translation —The financial statements of the Company’s foreign subsidiaries where the operations are primarily denominated in the foreign currency are translated into U.S. dollars for reporting. Balance sheet accounts are translated at the current foreign exchange rate at the end of each period and income statement accounts are translated at the average foreign exchange rate for each period. Gains and losses on foreign currency translations are reflected as a currency translation adjustment, net of tax, in accumulated other comprehensive income (loss). Foreign currency transaction gains and losses are included in other income (expense). During 2018, the Company substantially completed the liquidation of the investment in its Brazil and Australia operations. Refer to Note 7, Fair Value Measurements, for further discussion of the closeout. Recent Accounting Pronouncements — In January 2017, the Financial Accounting Standards Board (“FASB” issued Accounting Standard Update No. 2017-04 (“ASU 2017-04”), Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The amendment removes the requirement to compare the implied fair value of goodwill with its carrying amount as part of step 2 of the goodwill impairment test. The guidance is effective for fiscal years beginning after December 15, 2019. The Company does not anticipate that the adoption of ASU 2017-04 will have a material effect on the Company’s consolidated financial statements. In February 2016, the FASB issued Accounting Standard Update No. 2016-02 (“ASU 2016-02”), Leases (Topic 842) and subsequently issued other Accounting Standard Updates related to the Accounting Standards Codification Topic 842 (collectively, “ASC 842”). The FASB issued ASC 842 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 guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods. The Company adopted ASC 842 as of January 1, 2019 using the package of practical expedients that allow entities to retain the classification of lease contracts existing as of the date of adoption. Further, the Company adopted ASC 842 using the transition method under which entities initially apply ASC 842 at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under this method, the comparative periods presented in the financial statements prior to the adoption date would not be adjusted to apply ASC 842. Additionally, the Company elected to combine lease and non-lease components, such as common area maintenance costs, in calculating the operating lease assets and operating lease liabilities for all asset groups except for the Company’s dredges. Upon the adoption of the new lease guidance, the Company recorded a cumulative net adjustment of $2,802 to the beginning retained earnings balance. Refer to Note 4, Leases, for further discussion of the adoption of ASC 842.

Earnings Per Share

Earnings Per Share	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Earnings Per Share	2. EARNINGS PER SHARE Basic earnings per share is computed by dividing net income attributable to common stockholders by the weighted-average number of common shares outstanding during the reporting period. Diluted earnings per share is computed similar to basic earnings per share except that it reflects the potential dilution that could occur if dilutive securities or other obligations to issue common stock were exercised or converted into common stock. The computations for basic and diluted earnings (loss) per share for the years ended December 31, 2019, 2018 and 2017 are as follows: (shares in thousands) 2019 2018 2017 Income (loss) from continuing operations $ 55,668 $ 11,016 $ (15,368 ) Loss on discontinued operations, net of income taxes (6,329 ) (17,309 ) (15,892 ) Net income (loss) $ 49,339 $ (6,293 ) $ (31,260 ) Weighted-average common shares outstanding — basic 63,597 62,236 61,365 Effect of stock options and restricted stock units 1,445 1,371 — Weighted-average common shares outstanding — diluted 65,042 63,607 61,365 Earnings (loss) per share from continuing operations — basic $ 0.88 $ 0.18 $ (0.25 ) Earnings (loss) per share from continuing operations — diluted $ 0.86 $ 0.17 $ (0.25 ) For the year ended December 31, 2017 the dilutive effect of 716 stock options (“NQSO”) and restricted stock units (“RSU”) were excluded from the diluted weighted-average common shares outstanding as the Company incurred a loss during the period. For the years ended December 31, 2019, 2018 and 2017 the following amounts of NQSOs and RSUs were excluded from the calculation of diluted earnings per share based on the application of the treasury stock method, as such NQSOs and RSUs were determined to be anti-dilutive: (shares in thousands) 2019 2018 2017 Effect of stock options and restricted stock units 16 1,285 2,476

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Property and Equipment	3. PROPERTY AND EQUIPMENT Property and equipment at December 31, 2019 and 2018 are as follows: 2019 2018 Land $ 9,992 $ 9,992 Buildings and improvements 5,071 5,071 Furniture and fixtures 16,299 14,087 Operating equipment 738,375 710,128 Total property and equipment 769,737 739,278 Accumulated depreciation (395,141 ) (369,415 ) Property and equipment — net $ 374,596 $ 369,863 Operating equipment of $3,970 and $3,537 was classified as held for sale, excluded from property and equipment, as of December 31, 2019 and 2018, respectively. Depreciation expense was $37,145, $50,389 and $55,962, for the years ended December 31, 2019, 2018 and 2017, respectively. For more information about changes in assets held for sale and depreciation expense related to the Company’s restructuring refer to Note 12, Restructuring Charges.

Leases

Leases	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Leases	4. LEASES The Company leases certain operating equipment and office facilities under long-term operating leases expiring at various dates through 2025. Leases with an initial term greater than twelve months are recorded on the Company’s balance sheet as an operating lease asset and operating lease liability and are measured at the present value of lease payments over the lease term. Substantially all of the Company’s leases are classified as operating leases. Leases with an initial term of twelve months or less with purchase options or extension options that are not reasonably certain to be exercised are not recorded on the balance sheet. The Company recognizes lease expense for these leases on a straight-line basis over the lease term. The equipment leases contain renewal or purchase options that specify prices at the then fair value upon the expiration of the lease terms. The leases also contain default provisions that are triggered by an acceleration of debt maturity under the terms of the Company’s Amended Credit Agreement, or, in certain instances, cross default to other equipment leases and certain lease arrangements require that the Company maintain certain financial ratios comparable to those required by its Amended Credit Agreement. Additionally, the leases typically contain provisions whereby the Company indemnifies the lessors for the tax treatment attributable to such leases based on the tax rules in place at lease inception. The tax indemnifications do not have a contractual dollar limit. To date, no lessors have asserted any claims against the Company under these tax indemnification provisions. The exercise of lease renewal options is at the Company’s sole discretion and is considered in the measurement of operating lease assets and operating lease liabilities when it is reasonably certain the Company will exercise the option. Certain leases also include options to purchase the leased property. The depreciable life of assets and leasehold improvements are limited by the expected lease term, unless there is a transfer of title or purchase option reasonably certain of exercise. Lease cost The Company’s lease costs are recorded in cost of contract revenues and general and administrative expenses. For the year ended December 31, 2019, lease costs are as follows: Year Ended December 31, 2019 Operating lease cost $ 27,259 Short-term lease cost 70,382 Total lease cost $ 97,641 Total rent expense under long-term operating lease arrangements for the years ended December 31, 2018 and 2017 was $21,160 and $26,664, respectively. This excludes expenses for equipment and facilities rented on a short-term, as-needed basis. For more information about charges to rent expense during 2018 related to the Company’s restructuring refer to Note 12, Restructuring Charges. Lease terms and commitments As recorded on the balance sheet, the Company’s maturity analysis of its operating lease liabilities as of December 31, 2019 is as follows: 2020 $ 25,585 2021 21,537 2022 15,620 2023 9,752 2024 7,052 Thereafter 2,852 Minimum lease payments 82,398 Imputed interest 9,916 Present value of minimum operating lease payments $ 72,482 Future minimum operating lease payments at December 31, 2018, were as follows: 2019 $ 26,554 2020 22,349 2021 18,430 2022 13,552 2023 9,041 Thereafter 8,697 Total minimum operating lease payments $ 98,623 As most of the Company’s leases do not provide an implicit rate, the Company used its incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. At the date of adoption of ASC 842, the Company used the incremental borrowing rate as of December 31, 2018, for operating leases that commenced prior to that date. Additional information related to the Company’s leases as of December 31, 2019 is as follows: December 31, 2019 Weighted average remaining lease term 4.2 years Weighted average discount rate 6.7 % Supplemental information related to leases during the year ended December 31, 2019 is as follows: Year Ended December 31, 2019 Operating cash flows from operating leases $ (27,235 ) Operating lease liabilities arising from obtaining new operating lease assets $ 13,149

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued Expenses	5. ACCRUED EXPENSES Accrued expenses at December 31, 2019 and 2018 were as follows: 2019 2018 Payroll and employee benefits $ 16,859 $ 15,298 Insurance 15,702 13,724 Contract reserves 6,248 1,709 Interest 3,284 3,448 Income and other taxes 1,597 1,175 Fuel hedge contracts — 4,710 Accrued rent — 496 Other 7,535 7,791 Total accrued expenses $ 51,225 $ 48,351

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Long-Term Debt	6. LONG-TERM DEBT Long-term debt at December 31, 2019 and 2018 were as follows: 2019 2018 Revolving credit facility $ — $ 11,500 8% Senior Notes 322,843 321,950 Subtotal 322,843 333,450 Current portion of revolving credit facility — (11,500 ) Total $ 322,843 $ 321,950 Credit agreement On May 3, 2019, the Company, Great Lakes Dredge & Dock Company, LLC, NASDI Holdings, LLC, Great Lakes Dredge & Dock Environmental, Inc., Great Lakes Environmental & Infrastructure Solutions, LLC, Great Lakes U.S. Fleet Management, LLC, and Drews Services LLC (collectively, the “Credit Parties”) entered into an amended and restated revolving credit and security agreement (as amended, supplemented or otherwise modified from time to time, the “Amended Credit Agreement”) with certain financial institutions from time to time party thereto as lenders, PNC Bank, National Association, as Agent (the “Agent”), PNC Capital Markets, CIBC Bank USA, Suntrust Robinson Humphrey, Inc. and Bank of America, N.A., as Joint Lead Arrangers and Joint Bookrunners, and HSBC USA, N.A., as Documentation Agent. The Amended Credit Agreement amends and restates the prior Revolving Credit and Security Agreement dated as of December 30, 2016 (as amended, the “Prior Credit Agreement”) by and among the financial institutions from time to time party thereto as lenders, the Agent and the Credit Parties party thereto, such that the terms and conditions of the Prior Credit Agreement have been subsumed and replaced in their entirety by the terms and conditions of the Amended Credit Agreement, including the amount available under the revolving credit facility. The terms of the Amended Credit Agreement are summarized below. The Amended Credit Agreement provides for a senior secured revolving credit facility in an aggregate principal amount of up to $200,000 of which the full amount is available for the issuance of standby letters of credit. The maximum borrowing capacity under the Amended Credit Agreement is determined by a formula and may fluctuate depending on the value of the collateral included in such formula at the time of determination. The Amended Credit Agreement also includes an increase option that will allow the Company to increase the senior secured revolving credit facility by an aggregate principal amount of up to $100,000. This increase is subject to lenders providing incremental commitments for such increase, the Credit Parties having adequate borrowing capacity and provided that no default or event of default exists both before and after giving effect to such incremental commitment increase. The Amended Credit Agreement contains customary representations and affirmative and negative covenants, including a springing financial covenant that requires the Credit Parties to maintain a fixed charge coverage ratio (ratio of earnings before income taxes, depreciation and amortization, net interest expenses, non-cash charges and losses and certain other non-recurring charges, minus capital expenditures, income and franchise taxes, to net cash interest expense plus scheduled cash principal payments with respect to debt plus restricted payments paid in cash) of not less than 1.10 to 1.00. The Amended Credit Agreement also contains customary events of default (including non-payment of principal or interest on any material debt and breaches of covenants) as well as events of default relating to certain actions by the Company’s surety bonding providers. The obligations of the Credit Parties under the Amended Credit Agreement will be unconditionally guaranteed, on a joint and several basis, by each existing and subsequently acquired or formed material direct and indirect domestic subsidiary of the Company. Borrowings under the Amended Credit Agreement will be used to pay fees and expenses related to the Amended Credit Agreement, finance acquisitions permitted under the Amended Credit Agreement, finance ongoing working capital and for other general corporate purposes. The Amended Credit Agreement matures on May 3, 2024; provided that the maturity date shall be accelerated to the date that is ninety-one days prior to the scheduled maturity date of the Company’s unsecured senior notes if the Company fails to refinance its unsecured senior notes prior to their scheduled maturity date. The refinanced 8% Senior Notes must have a maturity on or after the date that is 180 days after the maturity date of the Amended Credit Agreement. The obligations under the Amended Credit Agreement are secured by substantially all of the assets of the Credit Parties. The outstanding obligations thereunder shall be secured by a valid first priority perfected lien on substantially all of the U.S. flagged and located vessels of the Credit Parties and a valid perfected lien on all domestic accounts receivable and substantially all other assets of the Credit Parties, subject to the permitted liens and interests of other parties (including the Company’s surety bonding providers). Interest on the senior secured revolving credit facility of the Amended Credit Agreement is equal to either a Domestic Rate option or LIBOR option, at the Company’s election. As of the Closing Date, (a) the Domestic Rate option is the highest of (1) the base commercial lending rate of PNC Bank, National Association, as publicly announced, (2) the sum of the federal funds open rate plus 0.5% and (3) the sum of the daily LIBOR rate plus 1.0%, so long as a daily LIBOR rate is offered, ascertainable and not unlawful plus an interest margin of 0.5%; and (b) the LIBOR Rate option is the rate that applies for the applicable interest period on the Bloomberg page BBAMI (or such other substitute page or alternate source as agreed) plus an interest margin of 1.5%. After the date on which a borrowing base certificate is required to be delivered under Section 9.2 of the Amended Credit Agreement (commencing with the fiscal quarter ended September 30, 2019, the “Adjustment Date”), the Domestic Rate option will be the Domestic Rate plus an interest margin ranging between 0.5% and 1.0% and the LIBOR Rate option will be the LIBOR Rate plus an interest margin ranging between 1.5% and 2.0%, in each case, depending on the quarterly average undrawn availability on the Amended Credit Agreement. As of December 31, 2019, the Company had no borrowings on the revolver, $35,779 of letters of credit outstanding and $163,729 of availability under the Amended Credit Agreement. The availability under the Amended Credit Agreement is suppressed by $492 as of December 31, 2019 as a result of certain limitations set forth in the Amended Credit Agreement. Prior revolving credit agreement The Prior Credit Agreement was entered into on December 30, 2016 and before amended provided for a senior secured revolving credit facility in an aggregate principal amount of up to $250,000. Previous borrowings under the revolving credit facility bore interest at the option of the Company at either a LIBOR rate plus a margin of between 2.5% to 3.0% per annum or a base rate plus a margin of between 1.5% to 2.0% per annum. Senior notes and subsidiary guarantors The Company has outstanding $325,000 of 8.000% senior notes (“8% Senior Notes”) due May 15, 2022. In May 2017, the Company issued the 8% Senior Notes at 100% of face value resulting in net proceeds of $321,653, net of underwriting fees. In connection with the issuance of the 8% Senior Notes, the Company retired all of its $275,000 of 7.375% senior notes due February 2019 for $282,638, which included a tender premium and accrued and unpaid interest. The Company used the remaining net proceeds from the debt offering to reduce the Company’s indebtedness under its prior Credit Agreement. The Company’s obligations under these Senior Notes are guaranteed by certain of the Company’s 100% owned domestic subsidiaries. Such guarantees are full, unconditional and joint and several. The parent company issuer has no independent assets or operations and all non-guarantor subsidiaries have been determined to be minor. Other The Company enters into note arrangements to finance certain vessels and ancillary equipment. In February 2018, the Company completed a sale-leaseback of a vessel yielding net proceeds of $4,500. Included in this transaction was the retirement of the asset and related equipment note. The scheduled principal payments through the maturity date of the Company’s long-term debt at December 31, 2019, are as follows: Years Ending December 31, 2020 $ — 2021 — 2022 325,000 2023 — 2024 — Thereafter — Total $ 325,000 The Company incurred amortization of deferred financing fees for its long term debt of $2,231, $3,504 and $3,280 for each of the years ended December 31, 2019, 2018 and 2017. Such amortization is recorded as a component of interest expense.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	7. FAIR VALUE MEASUREMENTS Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. A fair value hierarchy has been established by GAAP that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The accounting guidance describes three levels of inputs that may be used to measure fair value: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. At times, the Company holds certain derivative contracts that it uses to manage foreign currency risk or commodity price risk. The Company does not hold or issue derivatives for speculative or trading purposes. The fair values of these financial instruments are summarized as follows: Fair Value Measurements at Reporting Date Using Description At December 31, 2019 Quoted Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable (Level 3) Fuel hedge contracts $ 849 $ — $ 849 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 4,710 $ — $ 4,710 $ — Fuel hedge contracts The Company is exposed to certain market risks, primarily commodity price risk as it relates to the diesel fuel purchase requirements, which occur in the normal course of business. The Company enters into heating oil commodity swap contracts to hedge the risk that fluctuations in diesel fuel prices will have an adverse impact on cash flows associated with its domestic dredging contracts. The Company’s goal is to hedge approximately 80% of the eligible fuel requirements for work in domestic backlog. As of December 31, 2019, the Company was party to various swap arrangements to hedge the price of a portion of its diesel fuel purchase requirements for work in its backlog to be performed through December 2020. As of December 31, 2019, there were 10.5 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted domestic fuel purchases through December 2020. Under these swap agreements, the Company will pay fixed prices ranging from $1.79 to $2.05 per gallon. At December 31, 2019, the fair value asset of the fuel hedge contracts was estimated to be $849 and is recorded in other current assets. At December 31, 2018, the fair value liability of the fuel hedge contracts was estimated to be $4,710, and is recorded in accrued liabilities. For fuel hedge contracts considered to be highly effective, the losses reclassified to earnings from changes in fair value of derivatives, net of cash settlements and taxes, for the year ended December 31, 2019 were $1,458. The remaining gains and losses included in the accumulated other comprehensive income (loss) at December 31, 2019 will be reclassified into earnings over the next twelve months, corresponding to the period during which the hedged fuel is expected to be utilized. Changes in the fair value of fuel hedge contracts not considered highly effective are recorded as cost of contract revenues in the Statement of Operations. The fair value of fuel hedges are corroborated using inputs that are readily observable in public markets; therefore, the Company determines fair values of these fuel hedges using Level 2 inputs. The Company is exposed to counterparty credit risk associated with non-performance of its various derivative instruments. The Company’s risk would be limited to any unrealized gains on current positions. To help mitigate this risk, the Company transacts only with counterparties that are rated as investment grade or higher. In addition, all counterparties are monitored on a continuous basis. The fair value of the fuel hedge contracts outstanding as of December 31, 2019 and 2018 is as follows: Balance Sheet Location Fair Value at December 31, 2019 2018 Asset derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Other current assets $ 849 $ — Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued liabilities $ — $ 4,710 Assets and liabilities measured at fair value on a nonrecurring basis All other nonfinancial assets and liabilities measured at fair value in the financial statements on a nonrecurring basis are subject to fair value measurements and disclosures. Nonfinancial assets and liabilities included in the consolidated balance sheets and measured on a nonrecurring basis consist of goodwill and long-lived assets. Assets included within assets held for sale are reclassified from property and equipment at fair value less cost to sell. Goodwill and long-lived assets are measured at fair value to test for and measure impairment, if any, at least annually for goodwill or when necessary for both goodwill and long-lived assets. Accumulated other comprehensive income (loss) Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows: 2019 2018 2017 Cumulative translation adjustments—net of tax $ — $ 1,513 $ (41 ) Derivatives: Reclassification of derivative (gains) losses to earnings—net of tax 1,458 (1,569 ) (218 ) Change in fair value of derivatives—net of tax 2,646 (3,756 ) 1,407 Net unrealized (gain) loss on derivatives—net of tax 4,104 (5,325 ) 1,189 Total other comprehensive income (loss) $ 4,104 $ (3,812 ) $ 1,148 Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Statement of Operations Location 2019 2018 2017 Derivatives: Fuel hedge contracts Costs of contract revenues $ 1,975 $ (2,125 ) $ (358 ) Income tax (provision) benefit 517 (556 ) 140 $ 1,458 $ (1,569 ) $ (218 ) The Company substantially completed the liquidation of the investment in its Brazil and Australia operations during 2018. This liquidation resulted in the reversal of the Company’s cumulative translation adjustment. Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Statement of Operations Location 2018 Cumulative translation adjustment: Other expense $ (2,337 ) Income tax benefit 612 $ (1,725 ) Other financial instruments The carrying value of financial instruments included in current assets and current liabilities approximates fair value due to the short-term maturities of these instruments. Based on timing of the cash flows and comparison to current market interest rates, the carrying value of the senior revolving credit agreement approximates fair value. In May 2017, the Company issued a total of $325,000 of 8.000% senior notes due May 15, 2022, which were outstanding at December 31, 2019 (See Note 5, Long-Term Debt). The 8% Senior Notes are senior unsecured obligations of the Company and its subsidiaries that guarantee the Senior Notes. The fair value of the senior notes was $343,688 at December 31, 2019, which is a Level 1 fair value measurement as the senior notes value was obtained using quoted prices in active markets. It is impracticable to determine the fair value of outstanding letters of credit or performance, bid and payment bonds due to uncertainties as to the amount and timing of future obligations, if any.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Income Taxes	8. The Company’s income tax provision (benefit) from continuing and discontinued operations for the year ended December 31, 2019 is as follows: 2019 2018 2017 Income tax provision (benefit) from continuing operations $ 15,253 $ 5,437 $ (33,761 ) Income tax benefit from discontinued operations (4,556 ) (6,162 ) (10,052 ) Income tax provision (benefit) $ 10,697 $ (725 ) $ (43,813 ) The Company’s income (loss) from continuing operations before income tax from domestic and foreign continuing operations for the years ended December 31, 2019, 2018 and 2017 is as follows: 2019 2018 2017 Domestic operations $ 89,344 26,878 $ (12,263 ) Foreign operations (18,423 ) (10,425 ) (36,866 ) Total income (loss) from continuing operations before income tax $ 70,921 $ 16,453 $ (49,129 ) The provision (benefit) for income taxes from continuing operations as of December 31, 2019, 2018 and 2017 is as follows: 2019 2018 2017 Federal: Current $ — $ — $ (248 ) Deferred 14,052 3,702 (31,957 ) State: Current 212 48 29 Deferred 989 1,687 (1,598 ) Foreign: Current — — 13 Deferred — — — Total $ 15,253 5,437 $ (33,761 ) The Company’s income tax provision (benefit) from continuing operations reconciles to the provision at the statutory U.S. federal income tax rate of 21% for the years ended December 31, 2019 and 2018, and 35% for the year ended December 31, 2017 as follows: 2019 2018 2017 Tax provision (benefit) at statutory U.S. federal income tax rate $ 14,893 $ 3,455 $ (17,194 ) State income tax — net of federal income tax benefit 3,049 937 (1,746 ) Impact of Tax Cuts and Job Act — — (15,720 ) Change in state law regarding NOL carryforwards — 658 — Change in deferred state tax rate (1,835 ) — — Stock based compensation (1,266 ) (8 ) — Nondeductible officer compensation 1,021 201 — Research and development tax credits (452 ) (218 ) (170 ) Changes in unrecognized tax benefits (56 ) 14 10 Changes in valuation allowance (3 ) 116 1,152 Other (98 ) 282 (93 ) Income tax provision (benefit) $ 15,253 $ 5,437 $ (33,761 ) On December 22, 2017, the U.S. government enacted comprehensive tax legislation referred to as the Tax Act. The Tax Act makes broad and complex changes to the U.S. tax code, including but not limited to (1) reducing the U.S. federal corporate tax rate from 35% to 21%; (2) requiring companies to pay a one-time transition tax on certain unrepatriated earnings of foreign subsidiaries; (3) generally eliminating U.S. federal income taxes on dividends from foreign subsidiaries; (4) requiring a current inclusion in U.S. federal taxable income of certain earnings of controlled foreign corporations; (5) eliminating the corporate alternative minimum tax (AMT); (6) creating the base erosion anti-abuse tax (BEAT), a new minimum tax; (7) creating a new limitation on deductible interest expense; and (8) changing rules related to uses and limitations of net operating loss carryforwards created in tax years beginning after December 31, 2017. The Company completed its calculation of the income tax effect of the Tax Act for the year ended December 31, 2017, from continuing operations. As the Company was in a net deferred tax liability position as of the date of enactment of the Tax Act, the impact to it was a deferred income tax benefit of $15,720, primarily as a result of the reduction in the U.S. federal income tax rate. The other changes in tax law do not materially impact the Company for the year. At December 31, 2019 and 2018, the Company had loss carryforwards for federal income tax purposes of $137,100 and $168,650 respectively, which expire between 2034 and 2037. At December 31, 2019 and 2018, the Company had gross net operating loss carryforwards for state income tax purposes totaling $223,634 and $190,901, respectively, which expire between 2023 and 2029. Due to changes in state tax law enacted during 2016 in a certain state, a valuation allowance was established. In 2017, the valuation allowance was increased by $1,152 and by $116 in 2018. However, in 2019 the valuation allowance decreased by $3. The Company also has foreign gross net operating loss carryforwards of approximately $6,777 and $9,533 as of December 31, 2019 and 2018, of which $2,407 expires between 2019 and 2029. The remaining amount of $4,370 may be carried forward indefinitely. At December 31, 2019 and 2018, a full valuation allowance has been established for the deferred tax asset of $1,717 and $2,338 related to foreign net operating loss carryforwards, respectively, as the Company believes it is more likely than not that the net operating loss carryforwards will not be realized. The Company does not expect that total unrecognized tax benefits will significantly increase or decrease within the next 12 months. Below is a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of each period. 2019 2018 2017 Unrecognized tax benefits — January 1 $ 157 $ 157 $ 157 Gross increases — tax positions in prior period — — — Gross increases — current period tax positions — — — Gross decreases — expirations — — — Gross decreases — tax positions in prior period (157 ) — — Unrecognized tax benefits — December 31, $ — $ 157 $ 157 The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. As of December 31, 2019 the Company had no interest and penalties recorded and as of December 31, 2018 and December 31, 2017 it had approximately $71 and $53 of interest and penalties recorded, respectively. The Company files income tax returns at the U.S. federal level and in various state and foreign jurisdictions. U.S. federal income tax years prior to 2016 are closed and no longer subject to examination. With few exceptions, the statute of limitations in state taxing jurisdictions in which the Company operates has expired for all years prior to 2015. In foreign jurisdictions in which the Company operates, years prior to 2014 are closed and are no longer subject to examination. The Company’s deferred tax assets (liabilities) at December 31, 2019 and 2018 are as follows: 2019 2018 Deferred tax assets: Operating lease assets $ 18,301 $ — Accrued liabilities 7,426 9,287 Federal NOLs 28,791 35,417 Foreign NOLs 1,717 2,338 State NOLs 9,505 10,796 Tax credit carryforwards 2,620 2,159 Charitable contribution 66 910 Valuation allowance (3,495 ) (4,786 ) Total deferred tax assets 64,931 56,121 Deferred tax liabilities: Depreciation and amortization (82,115 ) (78,967 ) Operating lease liabilities (18,334 ) — Other liabilities (222 ) — Total deferred tax liabilities (100,671 ) (78,967 ) Net noncurrent deferred tax liabilities $ (35,740 ) $ (22,846 ) Deferred tax assets relate primarily to reserves and other liabilities for costs and expenses not currently deductible for tax purposes as well as net operating loss and other carryforwards. Deferred tax liabilities relate primarily to the cumulative difference between book depreciation and amounts deducted for tax purposes. The Company evaluates its ability to realize deferred tax assets by considering all available positive and negative evidence. This evidence includes its cumulative earnings or losses in recent years. The Company further considers the impact on these cumulative earnings or losses of discontinued operations and other divested operations and joint ventures, restructuring charges and other nonrecurring adjustments that are not indicative of its ability to generate taxable income in future periods. The Company also considers sources of taxable income, such as the amount and timing of realization of its deferred tax liabilities relative to the timing of expiration of loss carryforwards. When it is estimated to be more likely than not that all or some portion of deferred tax assets will not be realized, the Company establishes a valuation allowance for the amount of such deferred tax assets considered to be unrealizable. After evaluating the positive and negative evidence for future realization of deferred tax assets, the Company recorded valuation allowances for foreign net operating loss carryforwards and certain state net operating loss carryforwards to reduce the balance of these deferred tax assets at December 31, 2019 and 2018 as it was more likely than not that the balance of these tax items would not be realized. By contrast, after evaluating the positive and negative evidence, the Company concluded that it was more likely than not that the deferred federal income tax asset and remaining state net operating loss carryforwards recorded at December 31, 2019 and 2018 would ultimately be realized and determined that no valuation allowance was required.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	9. SHARE-BASED COMPENSATION The Company’s 2017 Long-Term Incentive Plan (“Incentive Plan”) permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to its employees and directors for up to 3.3 million shares of common stock, plus an additional 1.7 million shares underlying equity awards issued under the 2007 Long-Term Incentive Plan. The Company may also issue share-based compensation as inducement awards to new employees upon approval of the Board of Directors. Compensation cost charged to expense related to share-based compensation arrangements was $6,908, $4,643 and $2,917, for the years ended December 31, 2019, 2018 and 2017, respectively. Non-qualified stock options The NQSO awards were granted with an exercise price equal to the market price of the Company’s common stock at the date of grant. The option awards generally vest in three equal annual installments commencing on the first anniversary of the grant date, and have ten year exercise periods. The fair value of the NQSOs was determined at the grant date using a Black-Scholes option pricing model, which requires the Company to make several assumptions. The risk-free interest rate is based on the U.S. Treasury yield curve in effect for the expected term of the option at the time of grant. The annual dividend yield on the Company’s common stock is based on estimates of future dividends during the expected term of the NQSOs. The expected life of the NQSOs was determined from historical exercise data providing a reasonable basis upon which to estimate the expected life. The volatility assumptions were based on historical volatility of Great Lakes. There is not an active market for options on the Company’s common stock and, as such, implied volatility for the Company’s stock was not considered. Additionally, the Company’s general policy is to issue new shares of registered common stock to satisfy stock option exercises or grants of restricted stock. No NQSO awards were granted in 2019, 2018 and 2017. The aggregate intrinsic value of stock options represents the difference between market value on the date of exercise and the option price. The aggregate intrinsic value of stock options exercised during 2019, 2018 and 2017 was $2,534, $116 and $6, respectively. A summary of stock option activity under the Incentive Plan as of December 31, 2019, and changes during the year ended December 31, 2019, is presented below: Options Shares Weighted Exercise Price Weighted-Average Remaining Contract Term (yrs) Aggregate Intrinsic Value ($000's) Outstanding as of January 1, 2019 1,160 $ 6.52 Granted — — Exercised (650 ) 6.24 Forfeited or Expired (6 ) 6.85 Outstanding as of December 31, 2019 504 $ 6.87 2.9 $ 2,250 Vested at December 31, 2019 504 $ 6.87 2.9 $ 2,250 Restricted stock units RSUs can either vest in equal portions over the three year vesting period or vest in one installment on the third anniversary of the grant date. The fair value of RSUs was based upon the Company’s stock price on the date of grant. A summary of the status of the Company’s non-vested RSUs as of December 31, 2019, and changes during the year ended December 31, 2019, is presented below: Nonvested Restricted Stock Units Shares Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2019 2,987 $ 4.87 Granted 587 8.64 Vested (1,396 ) 4.56 Forfeited (369 ) 6.49 Outstanding as of December 31, 2019 1,809 $ 6.00 Expected to vest at December 31, 2019 1,670 $ 5.88 As of December 31, 2019, there was $4,984 of total unrecognized compensation cost related to non-vested RSUs granted under the Incentive Plan. That cost for non-vested RSUs is expected to be recognized over a weighted-average period of 1.5 years. The Incentive Plan permits the employee to use vested shares from RSUs to satisfy the grantee’s U.S. federal income tax liability resulting from the issuance of the shares through the Company’s retention of that number of common shares having a market value as of the vesting date equal to such tax obligation up to the minimum statutory withholding requirements. The amount related to shares used for such tax withholding obligations was approximately $5,008 and $1,205 for the years ended December 31, 2019 and 2018, respectively. Director compensation The Company uses a combination of cash and share-based compensation to attract and retain qualified candidates to serve on its Board of Directors. Compensation is paid to non-employee directors. Directors who are employees receive no additional compensation for services as members of the Board or any of its committees. Share-based compensation is paid pursuant to the Incentive Plan. Each non-employee director of the Company receives an annual retainer of $155, payable quarterly in arrears, and is generally paid 50% in cash and 50% in common stock or deferred restricted stock units of the Company. Directors may elect to receive some or all of the cash retainer in common stock or deferred restricted stock units. In 2018, the Chairman of the Board received an additional $100 of annual compensation, paid 100% in common stock. In the years ended December 31, 2019, 2018 and 2017, 78 thousand, 156 thousand and 207 thousand shares, respectively, of the Company’s common stock or restricted stock units were issued to non-employee directors under the Incentive Plan.

Revenue

Revenue	12 Months Ended
	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Revenue	10. REVENUE The Company’s revenue is derived from contracts for services with federal, state, local and foreign governmental entities and private customers. Revenues are generally derived from the enhancement or preservation of navigability of waterways or the protection of shorelines through the removal or replenishment of soil, sand or rock. Performance obligations A performance obligation is a promise in a contract to transfer a distinct good or service to the customer, and is the unit of account upon which the Company’s revenue is calculated. A contract’s transaction price is allocated to each distinct performance obligation and recognized as revenue as the performance obligation is satisfied. Fixed-price contracts, which comprise substantially all of the Company’s revenue, will most often represent a single performance obligation as the promise to transfer the individual services is not separately identifiable from other promises in the contracts and, therefore, not distinct. The Company capitalizes certain pre-contract and pre-construction costs, and defers recognition over the life of the contract. The Company’s performance obligations are satisfied over time and revenue is recognized using contract fulfillment costs incurred to date compared to total estimated costs at completion, also known as cost-to-cost, to measure progress towards completion. As the Company’s performance creates an asset that the customer controls, this method provides a faithful depiction of the transfer of an asset to the customer. Generally, the Company has an enforceable right to payment for performance completed to date. The Company typically satisfies its performance obligations upon completion of service. The majority of the Company’s contracts are completed in a year or less. At December 31, 2019, the Company had $589,406 of remaining performance obligations, which the Company refers to as total backlog. Approximately 96% of the Company’s backlog will be completed in 2020 with the remaining balance expected to be completed by 2021. Transaction price The transaction price is calculated using the Company’s estimated costs to complete a project. These costs are based on the types of equipment required to perform the specified service, project site conditions, the estimated project duration, seasonality, location and complexity of a project. The nature of the Company’s contracts gives rise to several types of variable consideration, including pay on quantity dredged for dredging projects and dredging project contract modifications. Estimated pay quantity is the amount of material the Company expects to dredge for which it will receive payment. Estimated quantity to be dredged is calculated using engineering estimates based on current survey data and the Company’s knowledge based on historical project experience. Contract modifications are changes in the scope or price (or both) of a contract that are approved by the parties to the contract. The Company recognizes a contract modification when the parties to a contract approve a modification that either creates new, or changes existing, enforceable rights and obligations of the parties to the contract. Contract modifications are included in the transaction price only if it is probable that the modification estimate will not result in a significant reversal of revenue. Contract modifications are routine in the performance of the Company’s contracts. In most instances, contract modifications are for services that are not distinct, and, therefore, are accounted for as part of the existing contract. Revisions in estimated gross profit percentages are recorded in the period during which the change in circumstances is experienced or becomes known. As the duration of most of the Company’s contracts is one year or less, the cumulative net impact of these revisions in estimates, individually and in the aggregate across projects, does not significantly affect results across annual reporting periods. Provisions for estimated losses on contracts in progress are made in the period in which such losses are determined. Revenue by category Domestically, the Company’s work generally is performed in coastal waterways and deep water ports. The U.S. dredging market consists of four primary types of work: capital, coastal protection, maintenance and rivers & lakes. The following table sets forth, by type of work, the Company’s contract revenues for the years ended December 31, 2019, 2018 and 2017: Revenues 2019 2018 2017 Capital—U.S. $ 299,706 $ 333,037 $ 185,113 Capital—foreign 48,619 14,088 42,306 Coastal protection 182,369 175,923 191,070 Maintenance 104,753 53,427 134,923 Rivers & lakes 76,071 44,320 38,747 Total revenues $ 711,518 $ 620,795 $ 592,159 The following table sets forth, by type of customer, the Company’s contract revenues for the years ended December 31, 2019, 2018 and 2017: Revenues 2019 2018 2017 Federal government $ 581,157 $ 468,421 $ 375,276 State and local government 71,398 93,499 145,196 Private 10,344 44,787 29,381 Foreign 48,619 14,088 42,306 Total revenues $ 711,518 $ 620,795 $ 592,159 Contract balances Billings on contracts are generally submitted after verification with the customers of physical progress and are recognized as accounts receivable in the balance sheet. For billings that do not match the timing of revenue recognition, the difference between amounts billed and recognized as revenue is reflected in the balance sheet as either contract revenues in excess of billings or billings in excess of contract revenues. Certain pre-contract and pre-construction costs are capitalized and reflected as contract assets in the balance sheet. Customer advances, deposits and commissions are reflected in the balance sheet as contract liabilities. Accounts receivable at December 31, 2019 and December 31, 2018 are as follows: 2019 2018 Completed contracts $ 3,444 $ 8,592 Contracts in progress 9,490 48,418 Retainage 7,415 7,969 20,349 64,979 Allowance for doubtful accounts (564 ) (200 ) Total accounts receivable—net $ 19,785 $ 64,779 The components of contracts in progress at December 31, 2019 and December 31, 2018 are as follows: 2019 2018 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 104,620 $ 433,093 Amounts billed (86,074 ) (416,956 ) Costs and earnings in excess of billings for contracts in progress 18,546 16,137 Costs and earnings in excess of billings for completed contracts 6,126 3,928 Total contract revenues in excess of billings $ 24,672 $ 20,065 Current portion of contract revenues in excess of billings $ 22,560 $ 17,953 Long-term contract revenues in excess of billings 2,112 2,112 Total contract revenues in excess of billings $ 24,672 $ 20,065 Billings in excess of costs and earnings: Amounts billed $ (628,491 ) $ (260,691 ) Costs and earnings for contracts in progress 573,225 242,898 Total billings in excess of contract revenues $ (55,266 ) $ (17,793 ) At December 31, 2019 and 2018, costs to fulfill contracts with customers recognized as an asset were $10,300 and $13,129, respectively, and are recorded in other current assets and other noncurrent assets. These costs relate to pre-contract and pre-construction activities. During the years ended December 31, 2019 and 2018, the company amortized pre-contract and pre-construction costs of $11,468 and $15,411, respectively. The Company’s largest domestic customer is the U.S. Army Corps of Engineers (the “Corps”), which has responsibility for federally funded projects related to navigation and flood control of U.S. waterways. In 2019, 2018 and 2017, 81.7%, 75.5% and 63.4%, respectively, of contract revenues were earned from contracts with federal government agencies, including the Corps, as well as other federal entities such as the U.S. Coast Guard and U.S. Navy. During the year ended December 31, 2019, the Company recognized $2,103 of revenue related to the use of equipment by a customer working on a federal government contract. At December 31, 2019 and 2018, approximately 54.6% and 65.3% respectively, of accounts receivable, including contract revenues in excess of billings and retainage, were due on contracts with federal government agencies. The Company depends on its ability to continue to obtain federal government contracts, and indirectly, on the amount of federal funding for new and current government dredging projects. Therefore, the Company’s operations can be influenced by the level and timing of federal funding. The Company derived revenues and gross profit from foreign project operations for the years ended December 31, 2019, 2018, and 2017, as follows: 2019 2018 2017 Contract revenues $ 48,619 $ 14,088 $ 42,306 Costs of contract revenues (66,347 ) (19,866 ) (73,958 ) Gross profit $ (17,728 ) $ (5,778 ) $ (31,652 ) In 2019, 2018 and 2017, foreign revenues were primarily from work done in the Middle East. The majority of the Company’s long-lived assets are marine vessels and related equipment. At any point in time, the Company may employ certain assets outside of the U.S., as needed, to perform work on the Company’s foreign projects. As of December 31, 2019 and 2018, long-lived assets with a net book value of $31,872 and $30,601, respectively, were located outside of the U.S. Revenue from foreign projects has been concentrated in the Middle East which comprised less than 10% in 2019, 2018 and 2017. At December 31, 2019 and 2018, approximately 29% and less than 10%, respectively, of total accounts receivable, including retainage and contract revenues in excess of billings, were due on contracts in the Middle East.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2019
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	11. RETIREMENT PLANS The Company sponsors two 401(k) savings plans, one covering substantially all non-union salaried employees (“Salaried Plan”), a second covering its hourly employees (“Hourly Plan”). Under the Salaried Plan and the Hourly Plan, individual employees may contribute a percentage of compensation and the Company will match a portion of the employees’ contributions. The Salaried Plan also includes a discretionary profit-sharing component, permitting the Company to make discretionary employer contributions to all eligible employees of these plans. Additionally, the Company sponsors a Supplemental Savings Plan in which the Company makes contributions for certain key executives. The Company’s expense for matching, discretionary and Supplemental Savings Plan contributions for 2019, 2018 and 2017, was $5,168, $5,060 and $2,616, respectively. The Company also contributes to various multiemployer pension plans pursuant to collective bargaining agreements. In 2019, 2018 and 2017, the Company contributed $4,517, $4,207 and $4,699 respectively to all of the multiemployer plans that provide pension benefits in its continuing operations. The information available to the Company about the multiemployer plans in which it participates, whether via request to the plan or publicly available, is generally dated due to the nature of the reporting cycle of multiemployer plans and legal requirements under the Employee Retirement Income Security Act (“ERISA”) as amended by the Multiemployer Pension Plan Amendments Act (“MPPAA”). Based upon these plans’ most recently available annual reports, the Company’s contributions to these plans were less than 5% of each plan’s total contributions. The Company does not expect any future increased contributions to have a material negative impact on its financial position, results of operations or cash flows for future years. The risks of participating in multiemployer plans are different from single employer plans as assets contributed are available to provide benefits to employees of other employers and unfunded obligations from an employer that discontinues contributions are the responsibility of all remaining employers. In addition, in the event of a plan’s termination or the Company’s withdrawal from a plan, the Company may be liable for a portion of the plan’s unfunded vested benefits. However, information from the plans’ administrators is not available to permit the Company to determine its share, if any, of unfunded vested benefits.

Restructuring Charges

Restructuring Charges	12 Months Ended
	Dec. 31, 2019
Restructuring And Related Activities [Abstract]
Restructuring Charges	12. RESTRUCTURING CHARGES In 2017, a strategic review was begun to improve the Company's financial results in both domestic and international operations enabling debt reduction, improvements in return on capital and the continued renewal of its extensive fleet with new and efficient dredges to best serve its domestic and international clients. Management executed a plan to reduce general and administrative and overhead expenses, retire certain underperforming and underutilized assets, write-off pre-contract costs on a project that was never formally awarded and that the Company no longer intends to pursue and closeout the Company’s Brazil operations. The cumulative amounts incurred to date as a result of this plan, including amounts presented in discontinued operations, including severance costs of $3,549, asset retirements of $32,309, pre-contract costs of $6,441 and closeout costs of $4,194. Restructuring activities were completed in 2018. Restructuring charges recognized for the above actions for the years ended December 31, 2018 and 2017 are summarized as follows: 2018 2017 Costs of contract revenues—depreciation $ 6,759 $ 6,859 Costs of contract revenues—other 2,292 16,102 General and administrative expenses 185 1,189 Loss on sale of assets—net 4,572 4,691 Other expense 2,337 — Total 16,145 28,841 The Company accrued severance expense of $662 at December 31, 2018, respectively, which has been settled in 2019. Accrued severance is included in accrued expenses.

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	13. COMMITMENTS AND CONTINGENCIES Commercial commitments Performance and bid bonds are customarily required for dredging and marine construction projects, as well as some environmental & infrastructure projects. The Company has bonding agreements with Argonaut Insurance Company, Berkley Insurance Company, Chubb Surety and Liberty Mutual Insurance Company In connection with the sale of its historical demolition business, the Company was obligated to keep in place the surety bonds on pending demolition projects for the period required under the respective contract for a project and issued Zurich a letter of credit related to this exposure. In February 2017, the Company was notified by Zurich of an alleged default triggered on a historical demolition surety performance bond in the aggregate of approximately $20,000 for failure of the contractor to perform in accordance with the terms of a project. In May 2017, Zurich drew upon the letter of credit in the amount of $20,881. In order to fund the draw on the letter of credit in May 2017, the Company had to increase the borrowings on its revolving credit facility. As the outstanding letters of credit previously reduced the Company’s availability under the revolving credit facility, this draw down on the Company’s letter of credit did not impact its liquidity or capital availability. Pursuant to the terms of sale of its historical demolition business, the Company received an indemnification from the buyer for losses resulting from the bonding arrangement. The Company intends to aggressively pursue enforcement of the indemnification provisions if the buyer of the historical demolition business is found to be in default of its obligations. The Company cannot estimate the amount or range of recoveries related to the indemnification or resolution of the Company’s responsibilities under the surety bond. The surety bond claim impact has been included in discontinued operations and is discussed in Note 14, Business Combinations and Dispositions. Certain foreign projects performed by the Company have warranty periods, typically spanning no more than one to three years beyond project completion, whereby the Company retains responsibility to maintain the project site to certain specifications during the warranty period. Generally, any potential liability of the Company is mitigated by insurance, shared responsibilities with consortium partners, and/or recourse to owner-provided specifications. Legal proceedings and other contingencies As is customary with negotiated contracts and modifications or claims to competitively bid contracts with the federal government, the government has the right to audit the books and records of the Company to ensure compliance with such contracts, modifications, or claims, and the applicable federal laws. The government has the ability to seek a price adjustment based on the results of such audit. Any such audits have not had, and are not expected to have, a material impact on the financial position, operations, or cash flows of the Company. Various legal actions, claims, assessments and other contingencies arising in the ordinary course of business are pending against the Company and certain of its subsidiaries. The Company will defend itself vigorously on all matters. These matters are subject to many uncertainties, and it is possible that some of these matters could ultimately be decided, resolved, or settled adversely to the Company. Although the Company is subject to various claims and legal actions that arise in the ordinary course of business, except as described below, the Company is not currently a party to any material legal proceedings or environmental claims. The Company records an accrual when it is probable a liability has been incurred and the amount of loss can be reasonably estimated. The Company does not believe any of these proceedings, individually or in the aggregate, would be expected to have a material effect on results of operations, cash flows or financial condition. On April 23, 2014, the Company completed the sale of NASDI, LLC (“NASDI”) and Yankee Environmental Services, LLC (“Yankee”), which together comprised the Company’s historical demolition business, to a privately owned demolition company. Legal actions brought by the Company to enforce the buyer’s obligations under the sale agreement are described below. On January 14, 2015, the Company and its subsidiary, NASDI Holdings, LLC, brought an action in the Delaware Court of Chancery to enforce the terms of the Company's agreement to sell NASDI and Yankee. Under the terms of the agreement, the Company received cash of $5,309 and retained the right to receive additional proceeds based upon future collections of outstanding accounts receivable and work in process existing at the date of close. The Company seeks specific performance of the buyer’s obligation to collect and to remit the additional proceeds, and other related relief. Defendants have filed counterclaims alleging that the Company misrepresented the quality of its contracts and receivables prior to the sale. The Company denies defendants’ allegations. In June 2019, the U.S. Attorney’s Office for the Eastern District of Louisiana informed the Company that it intends to file criminal charges against the Company in connection with a September 2016 oil spill. The oil spill occurred during the Company’s Cheniere Ronquille project, allegedly resulting in the discharge of around 125 barrels of crude oil in Bay Long, Louisiana. The Company has cooperated with the U.S. Attorney’s Office in its investigation of the oil spill and believes that criminal charges are not warranted. On September 27, 2019, the EPA Region 4 filed an administrative complaint against the Company relating to a project the Company performed at PortMiami from 2013-2015. The EPA is alleging violations of Section 103 of the Marine Protection, Research, and Sanctuaries Act (“MPRSA”) and failure to report violations of the MPRSA. The EPA seeks the statutory maximum penalty of $75 per violation of the MPRSA. The Company disagrees with the EPA on whether violations occurred and, if any violation did occur, the appropriate penalty calculation. Except as noted above, the Company has not accrued any amounts with respect to the above matters as the Company does not believe, based on information currently known to it, that a loss relating to these matters is probable, and an estimate of a range of potential losses relating to these matters cannot reasonably be made.

Business Dispositions

Business Dispositions	12 Months Ended
	Dec. 31, 2019
Discontinued Operations And Disposal Groups [Abstract]
Business Dispositions	14. BUSINESS DISPOSITIONS Discontinued operations During the second quarter of 2019, the Company completed the sale of the historical environmental & infrastructure business. Under the terms of the agreement, the Company received cash of $17,500 in the second quarter of 2019 and received an additional $857 in the third quarter of 2019. The results of the business have been reported in discontinued operations as follows: 2019 2018 2017 Revenue $ 25,040 $ 76,843 $ 112,607 Loss before income taxes from discontinued operations $ (8,253 ) $ (9,361 ) $ (25,944 ) Loss on disposal of assets held for sale (2,632 ) (14,110 ) — Income tax benefit 4,556 6,162 10,052 Loss from discontinued operations, net of income taxes $ (6,329 ) $ (17,309 ) $ (15,892 ) The major classes of assets and liabilities of businesses reported as discontinued operations are shown below: 2018 Assets: Accounts receivable—net $ 13,943 Contract revenues in excess of billings 9,971 Other current assets 865 Assets held for sale $ 24,779 Property and equipment—net 6,612 Goodwill 7,000 Other intangible assets—net 372 Other assets 1,699 Reserve for loss on disposal (14,110 ) Assets held for sale—noncurrent $ 1,573 Liabilities: Accounts payable $ 8,343 Accrued expenses 4,380 Other current liabilities 1,217 Liabilities held for sale 13,940 Other liabilities 146 Liabilities held for sale—noncurrent $ 146

Schedule II-Valuation and Quali

Schedule II-Valuation and Qualify Accounts	12 Months Ended
	Dec. 31, 2019
Valuation And Qualifying Accounts [Abstract]
Schedule II-Valuation and Qualifying Accounts	Great Lakes Dredge & Dock Corporation Schedule II—Valuation and Qualifying Accounts For the Years Ended December 31, 2019, 2018 and 2017 (In thousands) Beginning Balance Additions Deductions Ending balance Description Year ended December 31, 2017 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ 258 $ — $ (258 ) $ — Valuation allowance for deferred tax assets 7,133 1,152 (3,991 ) 4,294 Total $ 7,391 $ 1,152 $ (4,249 ) $ 4,294 Year ended December 31, 2018 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ — $ 200 $ — $ 200 Valuation allowance for deferred tax assets 4,294 492 — 4,786 Total $ 4,294 $ 692 $ — $ 4,986 Year ended December 31, 2019 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ 200 $ 364 $ — $ 564 Valuation allowance for deferred tax assets 4,786 — (1,291 ) 3,495 Total $ 4,986 $ 364 $ (1,291 ) $ 4,059

Nature of Business and Summar_2

Nature of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Principles of Consolidation and Basis of Presentation	Principles of Consolidation and Basis of Presentation —The consolidated financial statements include the accounts of Great Lakes Dredge & Dock Corporation and its majority-owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation. The equity method of accounting is used for investments in unconsolidated investees in which the Company has significant influence, but not control. Other investments, if any, are carried at cost.
Use of Estimates	Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect certain reported amounts and disclosures. Accordingly, actual results could differ from those estimates.
Revenue and Cost Recognition on Contracts	Revenue and Cost Recognition on Contracts — Prior to January 1, 2018, the Company measured completion based on engineering estimates of the physical percentage completed for dredging contracts. Under the new accounting principle, revenue is recognized using contract fulfillment costs incurred to date compared to total estimated costs at completion, also known as cost-to-cost, to measure progress towards completion. Additionally, the Company capitalizes certain pre-contract and pre-construction costs, and defers recognition over the life of the contract. Fixed-price contracts, which comprise substantially all of the Company’s revenue, will most often represent a single performance obligation as the promise to transfer the individual services is not separately identifiable from other promises in the contracts and, therefore, not distinct. The Company’s performance obligations are satisfied over time and revenue is recognized using the cost-to-cost method, described above. Contract modifications are changes in the scope or price (or both) of a contract that are approved by the parties to the contract. The Company recognizes a contract modification when the parties to a contract approve a modification that either creates new, or changes existing, enforceable rights and obligations of the parties to the contract. Contract modifications are included in the transaction price only if it is probable that the modification estimate will not result in a significant reversal of revenue. Revisions in estimated gross profit percentages are recorded in the period during which the change in circumstances is experienced or becomes known. As the duration of most of the Company’s contracts is one year or less, the cumulative net impact of these revisions in estimates, individually and in the aggregate across projects, does not significantly affect results across annual reporting periods. Provisions for estimated losses on contracts in progress are made in the period in which such losses are determined. The components of costs of contract revenues include labor, equipment (including depreciation, maintenance, insurance and long-term rentals), subcontracts, fuel, supplies, short-term rentals and project overhead. Hourly labor generally is hired on a project-by-project basis. The Company is a party to numerous collective bargaining agreements in the U.S. that govern its relationships with its unionized hourly workforce.
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, unless completion of such contracts extends significantly beyond one year.
Cash Equivalents	Cash Equivalents —The Company considers all highly liquid investments with a maturity at purchase of three months or less to be cash equivalents.
Accounts Receivable	Accounts Receivable —Accounts receivable represent amounts due or billable under the terms of contracts with customers, including amounts related to retainage. The Company anticipates collection of retainage generally within one year, and accordingly presents retainage as a current asset. The Company provides an allowance for estimated uncollectible accounts receivable when events or conditions indicate that amounts outstanding are not recoverable.
Inventories	Inventories —Inventories consist of pipe and spare parts used in the Company’s dredging operations. Pipe and spare parts are purchased in large quantities; therefore, a certain amount of pipe and spare part inventories is not anticipated to be used within the current year and is classified as long-term. Spare part inventories are stated at weighted average historical cost, and are charged to expense when used in operations. Pipe inventory is recorded at cost and amortized to expense over the period of its use.
Property, Plant and Equipment	Property and Equipment —Capital additions, improvements, and major renewals are classified as property and equipment and are carried at depreciated cost. Maintenance and repairs that do not significantly extend the useful lives of the assets or enhance the capabilities of such assets are charged to expenses as incurred. Depreciation is recorded over the estimated useful lives of property and equipment using the straight-line method and the mid-year depreciation convention. The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30 Leasehold improvements are amortized over the shorter of their remaining useful lives or the remaining terms of the leases.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets —Goodwill represents the excess of acquisition cost over fair value of the net assets acquired. Other identifiable intangible assets may represent developed technology and databases, customer relationships, and customer contracts acquired in business combinations. Goodwill is tested annually for impairment in the third quarter of each year, or more frequently should circumstances dictate. GAAP requires that goodwill of a reporting unit be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company assesses the fair values of its reporting unit using both a market-based approach and an income-based approach. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows. The income approach is dependent on a number of factors, including estimates of future market growth trends, forecasted revenues and expenses, appropriate discount rates and other variables. The estimates are based on assumptions that the Company believes to be reasonable, but such assumptions are subject to unpredictability and uncertainty. Changes in these estimates and assumptions could materially affect the determination of fair value, and may result in the impairment of goodwill in the event that actual results differ from those estimates. The market approach measures the value of a reporting unit through comparison to comparable companies. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA. The Company analyzes companies that performed similar services or are considered peers. Due to the fact that there are no public companies that are direct competitors, the Company weighs the results of this approach less than the income approach. The Company has one operating segment which is also the Company’s one reportable segment and reporting unit of which the Company tests goodwill for impairment. The historical environmental & infrastructure segment, which the Company sold during the second quarter of 2019, has been retrospectively presented as discontinued operations and assets and liabilities held for sale and is no longer reflected in continuing operations. The Company performed its most recent annual test of impairment as of July 1, 2019 with no indication of impairment as of the test date. The Company will perform its next scheduled annual test of goodwill in the third quarter of 2020 should no triggering events occur which would require a test prior to the next annual test.
Long-Lived Assets	Long-Lived Assets —Long-lived assets are comprised of property and equipment and intangible assets subject to amortization. Long-lived assets to be held and used are reviewed for possible impairment whenever events indicate that the carrying amount of such assets may not be recoverable by comparing the undiscounted cash flows associated with the assets to their carrying amounts. If such a review indicates an impairment, the carrying amount would be reduced to fair value. No triggering events were identified in 2019 or 2018. If long-lived assets are to be disposed, depreciation is discontinued, if applicable, and the assets are reclassified as held for sale at the lower of their carrying amounts or fair values less estimated costs to sell.
Self-insurance Reserves	Self-insurance Reserves —The Company self-insures costs associated with its seagoing employees covered by the provisions of Jones Act, workers’ compensation claims, hull and equipment liability, and general business liabilities up to certain limits. Insurance reserves are established for estimates of the loss that the Company may ultimately incur on reported claims, as well as estimates of claims that have been incurred but not yet reported. In determining its estimates, the Company considers historical loss experience and judgments about the present and expected levels of cost per claim. Trends in actual experience are a significant factor in the determination of such reserves.
Income Taxes	Income Taxes —The provision for income taxes includes federal, foreign, and state income taxes currently payable and those deferred because of temporary differences between the financial statement and tax basis of assets and liabilities. Recorded deferred income tax assets and liabilities are based on the estimated future tax effects of differences between the financial and tax basis of assets and liabilities, given the effect of currently enacted tax laws. In 2017, the U.S. government enacted comprehensive tax legislation referred to as the Tax Cuts and Jobs Act. Refer to Note 8, Income Taxes.
Hedging Instruments	Hedging Instruments —At times, the Company designates certain derivative contracts as a cash flow hedge as defined by GAAP. Accordingly, the Company formally documents, at the inception of each hedge, all relationships between hedging instruments and hedged items, as well as its risk-management objective and strategy for undertaking hedge transactions. This process includes linking all derivatives to highly-probable forecasted transactions. The Company formally assesses, at inception and on an ongoing basis, the effectiveness of hedges in offsetting changes in the cash flows of hedged items. Hedge accounting treatment may be discontinued when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the cash flows of a hedged item (including hedged items for forecasted future transactions), (2) the derivative expires or is sold, terminated or exercised, (3) it is no longer probable that the forecasted transaction will occur or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate. If management elects to stop hedge accounting, it would be on a prospective basis and any hedges in place would be recognized in accumulated other comprehensive income (loss) until all the related forecasted transactions are completed or are probable of not occurring.
Foreign Currency Translation	Foreign Currency Translation —The financial statements of the Company’s foreign subsidiaries where the operations are primarily denominated in the foreign currency are translated into U.S. dollars for reporting. Balance sheet accounts are translated at the current foreign exchange rate at the end of each period and income statement accounts are translated at the average foreign exchange rate for each period. Gains and losses on foreign currency translations are reflected as a currency translation adjustment, net of tax, in accumulated other comprehensive income (loss). Foreign currency transaction gains and losses are included in other income (expense). During 2018, the Company substantially completed the liquidation of the investment in its Brazil and Australia operations. Refer to Note 7, Fair Value Measurements, for further discussion of the closeout.
Recent Accounting Pronouncements	Recent Accounting Pronouncements — In January 2017, the Financial Accounting Standards Board (“FASB” issued Accounting Standard Update No. 2017-04 (“ASU 2017-04”), Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment . The amendment removes the requirement to compare the implied fair value of goodwill with its carrying amount as part of step 2 of the goodwill impairment test. The guidance is effective for fiscal years beginning after December 15, 2019. The Company does not anticipate that the adoption of ASU 2017-04 will have a material effect on the Company’s consolidated financial statements. In February 2016, the FASB issued Accounting Standard Update No. 2016-02 (“ASU 2016-02”), Leases (Topic 842) and subsequently issued other Accounting Standard Updates related to the Accounting Standards Codification Topic 842 (collectively, “ASC 842”). The FASB issued ASC 842 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 guidance is effective for fiscal years beginning after December 15, 2018, including interim periods within those annual periods. The Company adopted ASC 842 as of January 1, 2019 using the package of practical expedients that allow entities to retain the classification of lease contracts existing as of the date of adoption. Further, the Company adopted ASC 842 using the transition method under which entities initially apply ASC 842 at the adoption date and recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. Under this method, the comparative periods presented in the financial statements prior to the adoption date would not be adjusted to apply ASC 842. Additionally, the Company elected to combine lease and non-lease components, such as common area maintenance costs, in calculating the operating lease assets and operating lease liabilities for all asset groups except for the Company’s dredges. Upon the adoption of the new lease guidance, the Company recorded a cumulative net adjustment of $2,802 to the beginning retained earnings balance. Refer to Note 4, Leases, for further discussion of the adoption of ASC 842.

Nature of Business and Summar_3

Nature of Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Estimated Useful Lives By Class Of Assets	The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30

Earnings Per Share (Tables)

Earnings Per Share (Tables)	12 Months Ended
	Dec. 31, 2019
Earnings Per Share [Abstract]
Computations for Basic and Diluted Earnings (Loss) Per Share	The computations for basic and diluted earnings (loss) per share for the years ended December 31, 2019, 2018 and 2017 are as follows: (shares in thousands) 2019 2018 2017 Income (loss) from continuing operations $ 55,668 $ 11,016 $ (15,368 ) Loss on discontinued operations, net of income taxes (6,329 ) (17,309 ) (15,892 ) Net income (loss) $ 49,339 $ (6,293 ) $ (31,260 ) Weighted-average common shares outstanding — basic 63,597 62,236 61,365 Effect of stock options and restricted stock units 1,445 1,371 — Weighted-average common shares outstanding — diluted 65,042 63,607 61,365 Earnings (loss) per share from continuing operations — basic $ 0.88 $ 0.18 $ (0.25 ) Earnings (loss) per share from continuing operations — diluted $ 0.86 $ 0.17 $ (0.25 )
Schedule of Stock Options and Restricted Stock Units Excluded from Calculation of Anti-Diluted Earnings Per Share	For the years ended December 31, 2019, 2018 and 2017 the following amounts of NQSOs and RSUs were excluded from the calculation of diluted earnings per share based on the application of the treasury stock method, as such NQSOs and RSUs were determined to be anti-dilutive: (shares in thousands) 2019 2018 2017 Effect of stock options and restricted stock units 16 1,285 2,476

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2019
Property Plant And Equipment [Abstract]
Schedule of Property Plant and Equipment	Property and equipment at December 31, 2019 and 2018 are as follows: 2019 2018 Land $ 9,992 $ 9,992 Buildings and improvements 5,071 5,071 Furniture and fixtures 16,299 14,087 Operating equipment 738,375 710,128 Total property and equipment 769,737 739,278 Accumulated depreciation (395,141 ) (369,415 ) Property and equipment — net $ 374,596 $ 369,863

Leases (Tables)

Leases (Tables)	12 Months Ended
	Dec. 31, 2019
Leases [Abstract]
Schedule of Lease Costs	The Company’s lease costs are recorded in cost of contract revenues and general and administrative expenses. For the year ended December 31, 2019, lease costs are as follows: Year Ended December 31, 2019 Operating lease cost $ 27,259 Short-term lease cost 70,382 Total lease cost $ 97,641
Schedule of Maturity Analysis of Operating Lease Liabilities	As recorded on the balance sheet, the Company’s maturity analysis of its operating lease liabilities as of December 31, 2019 is as follows: 2020 $ 25,585 2021 21,537 2022 15,620 2023 9,752 2024 7,052 Thereafter 2,852 Minimum lease payments 82,398 Imputed interest 9,916 Present value of minimum operating lease payments $ 72,482
Future Minimum Operating Lease Payments	Future minimum operating lease payments at December 31, 2018, were as follows: 2019 $ 26,554 2020 22,349 2021 18,430 2022 13,552 2023 9,041 Thereafter 8,697 Total minimum operating lease payments $ 98,623
Schedule of Additional Information Related to Leases	Additional information related to the Company’s leases as of December 31, 2019 is as follows: December 31, 2019 Weighted average remaining lease term 4.2 years Weighted average discount rate 6.7 %
Supplemental Information Related to Leases	Supplemental information related to leases during the year ended December 31, 2019 is as follows: Year Ended December 31, 2019 Operating cash flows from operating leases $ (27,235 ) Operating lease liabilities arising from obtaining new operating lease assets $ 13,149

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses at December 31, 2019 and 2018 were as follows: 2019 2018 Payroll and employee benefits $ 16,859 $ 15,298 Insurance 15,702 13,724 Contract reserves 6,248 1,709 Interest 3,284 3,448 Income and other taxes 1,597 1,175 Fuel hedge contracts — 4,710 Accrued rent — 496 Other 7,535 7,791 Total accrued expenses $ 51,225 $ 48,351

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2019
Debt Disclosure [Abstract]
Schedule of Long-Term Debt	Long-term debt at December 31, 2019 and 2018 were as follows: 2019 2018 Revolving credit facility $ — $ 11,500 8% Senior Notes 322,843 321,950 Subtotal 322,843 333,450 Current portion of revolving credit facility — (11,500 ) Total $ 322,843 $ 321,950
Maturities of Long-Term Debt	The scheduled principal payments through the maturity date of the Company’s long-term debt at December 31, 2019, are as follows: Years Ending December 31, 2020 $ — 2021 — 2022 325,000 2023 — 2024 — Thereafter — Total $ 325,000

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2019
Fair Value Disclosures [Abstract]
Schedule of Fair Values of Financial Instruments and Nonfinancial Assets and Liabilities Measured at the Reporting Date	The fair values of these financial instruments are summarized as follows: Fair Value Measurements at Reporting Date Using Description At December 31, 2019 Quoted Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable (Level 3) Fuel hedge contracts $ 849 $ — $ 849 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2018 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 4,710 $ — $ 4,710 $ —
Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location	The fair value of the fuel hedge contracts outstanding as of December 31, 2019 and 2018 is as follows: Balance Sheet Location Fair Value at December 31, 2019 2018 Asset derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Other current assets $ 849 $ — Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued liabilities $ — $ 4,710
Changes in Components of Accumulated Other Comprehensive Income (Loss)	Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows: 2019 2018 2017 Cumulative translation adjustments—net of tax $ — $ 1,513 $ (41 ) Derivatives: Reclassification of derivative (gains) losses to earnings—net of tax 1,458 (1,569 ) (218 ) Change in fair value of derivatives—net of tax 2,646 (3,756 ) 1,407 Net unrealized (gain) loss on derivatives—net of tax 4,104 (5,325 ) 1,189 Total other comprehensive income (loss) $ 4,104 $ (3,812 ) $ 1,148
Adjustments Reclassified from Accumulated Balances Other Comprehensive Income (Loss) to Earnings	Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Statement of Operations Location 2019 2018 2017 Derivatives: Fuel hedge contracts Costs of contract revenues $ 1,975 $ (2,125 ) $ (358 ) Income tax (provision) benefit 517 (556 ) 140 $ 1,458 $ (1,569 ) $ (218 ) Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Statement of Operations Location 2018 Cumulative translation adjustment: Other expense $ (2,337 ) Income tax benefit 612 $ (1,725 )

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2019
Income Tax Disclosure [Abstract]
Schedule of Income tax Provision (Benefit) from Continuing and Discontinuing Operations	2019 2018 2017 Income tax provision (benefit) from continuing operations $ 15,253 $ 5,437 $ (33,761 ) Income tax benefit from discontinued operations (4,556 ) (6,162 ) (10,052 ) Income tax provision (benefit) $ 10,697 $ (725 ) $ (43,813 )
Income (Loss) from Continuing Operations before Income Tax from Domestic and Foreign Operations	2019 2018 2017 Domestic operations $ 89,344 26,878 $ (12,263 ) Foreign operations (18,423 ) (10,425 ) (36,866 ) Total income (loss) from continuing operations before income tax $ 70,921 $ 16,453 $ (49,129 )
Provision (Benefit) For Income Taxes	2019 2018 2017 Federal: Current $ — $ — $ (248 ) Deferred 14,052 3,702 (31,957 ) State: Current 212 48 29 Deferred 989 1,687 (1,598 ) Foreign: Current — — 13 Deferred — — — Total $ 15,253 5,437 $ (33,761 )
Income Tax Provision (Benefit) Reconciliation	2019 2018 2017 Tax provision (benefit) at statutory U.S. federal income tax rate $ 14,893 $ 3,455 $ (17,194 ) State income tax — net of federal income tax benefit 3,049 937 (1,746 ) Impact of Tax Cuts and Job Act — — (15,720 ) Change in state law regarding NOL carryforwards — 658 — Change in deferred state tax rate (1,835 ) — — Stock based compensation (1,266 ) (8 ) — Nondeductible officer compensation 1,021 201 — Research and development tax credits (452 ) (218 ) (170 ) Changes in unrecognized tax benefits (56 ) 14 10 Changes in valuation allowance (3 ) 116 1,152 Other (98 ) 282 (93 ) Income tax provision (benefit) $ 15,253 $ 5,437 $ (33,761 )
Reconciliation of Unrecognized Tax Benefits	2019 2018 2017 Unrecognized tax benefits — January 1 $ 157 $ 157 $ 157 Gross increases — tax positions in prior period — — — Gross increases — current period tax positions — — — Gross decreases — expirations — — — Gross decreases — tax positions in prior period (157 ) — — Unrecognized tax benefits — December 31, $ — $ 157 $ 157
Deferred Tax Assets (Liabilities)	2019 2018 Deferred tax assets: Operating lease assets $ 18,301 $ — Accrued liabilities 7,426 9,287 Federal NOLs 28,791 35,417 Foreign NOLs 1,717 2,338 State NOLs 9,505 10,796 Tax credit carryforwards 2,620 2,159 Charitable contribution 66 910 Valuation allowance (3,495 ) (4,786 ) Total deferred tax assets 64,931 56,121 Deferred tax liabilities: Depreciation and amortization (82,115 ) (78,967 ) Operating lease liabilities (18,334 ) — Other liabilities (222 ) — Total deferred tax liabilities (100,671 ) (78,967 ) Net noncurrent deferred tax liabilities $ (35,740 ) $ (22,846 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Summary of Stock Option Activity	A summary of stock option activity under the Incentive Plan as of December 31, 2019, and changes during the year ended December 31, 2019, is presented below: Options Shares Weighted Exercise Price Weighted-Average Remaining Contract Term (yrs) Aggregate Intrinsic Value ($000's) Outstanding as of January 1, 2019 1,160 $ 6.52 Granted — — Exercised (650 ) 6.24 Forfeited or Expired (6 ) 6.85 Outstanding as of December 31, 2019 504 $ 6.87 2.9 $ 2,250 Vested at December 31, 2019 504 $ 6.87 2.9 $ 2,250
Summary of Non-Vested Restricted Stock Units	A summary of the status of the Company’s non-vested RSUs as of December 31, 2019, and changes during the year ended December 31, 2019, is presented below: Nonvested Restricted Stock Units Shares Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2019 2,987 $ 4.87 Granted 587 8.64 Vested (1,396 ) 4.56 Forfeited (369 ) 6.49 Outstanding as of December 31, 2019 1,809 $ 6.00 Expected to vest at December 31, 2019 1,670 $ 5.88

Revenue (Tables)

Revenue (Tables)	12 Months Ended
	Dec. 31, 2019
Revenue From Contract With Customer [Abstract]
Summary of Type of Work and Customer, Contract Revenues	The following table sets forth, by type of work, the Company’s contract revenues for the years ended December 31, 2019, 2018 and 2017: Revenues 2019 2018 2017 Capital—U.S. $ 299,706 $ 333,037 $ 185,113 Capital—foreign 48,619 14,088 42,306 Coastal protection 182,369 175,923 191,070 Maintenance 104,753 53,427 134,923 Rivers & lakes 76,071 44,320 38,747 Total revenues $ 711,518 $ 620,795 $ 592,159 The following table sets forth, by type of customer, the Company’s contract revenues for the years ended December 31, 2019, 2018 and 2017: Revenues 2019 2018 2017 Federal government $ 581,157 $ 468,421 $ 375,276 State and local government 71,398 93,499 145,196 Private 10,344 44,787 29,381 Foreign 48,619 14,088 42,306 Total revenues $ 711,518 $ 620,795 $ 592,159
Schedule of Accounts Receivable	Accounts receivable at December 31, 2019 and December 31, 2018 are as follows: 2019 2018 Completed contracts $ 3,444 $ 8,592 Contracts in progress 9,490 48,418 Retainage 7,415 7,969 20,349 64,979 Allowance for doubtful accounts (564 ) (200 ) Total accounts receivable—net $ 19,785 $ 64,779
Components of Contracts in Progress	The components of contracts in progress at December 31, 2019 and December 31, 2018 are as follows: 2019 2018 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 104,620 $ 433,093 Amounts billed (86,074 ) (416,956 ) Costs and earnings in excess of billings for contracts in progress 18,546 16,137 Costs and earnings in excess of billings for completed contracts 6,126 3,928 Total contract revenues in excess of billings $ 24,672 $ 20,065 Current portion of contract revenues in excess of billings $ 22,560 $ 17,953 Long-term contract revenues in excess of billings 2,112 2,112 Total contract revenues in excess of billings $ 24,672 $ 20,065 Billings in excess of costs and earnings: Amounts billed $ (628,491 ) $ (260,691 ) Costs and earnings for contracts in progress 573,225 242,898 Total billings in excess of contract revenues $ (55,266 ) $ (17,793 )
Summary of Revenues and Gross Profit from Foreign Project Operations	The Company derived revenues and gross profit from foreign project operations for the years ended December 31, 2019, 2018, and 2017, as follows: 2019 2018 2017 Contract revenues $ 48,619 $ 14,088 $ 42,306 Costs of contract revenues (66,347 ) (19,866 ) (73,958 ) Gross profit $ (17,728 ) $ (5,778 ) $ (31,652 )

Restructuring charges (Tables)

Restructuring charges (Tables)	12 Months Ended
	Dec. 31, 2019
Restructuring And Related Activities [Abstract]
Schedule of Restructuring Charges	Restructuring charges recognized for the above actions for the years ended December 31, 2018 and 2017 are summarized as follows: 2018 2017 Costs of contract revenues—depreciation $ 6,759 $ 6,859 Costs of contract revenues—other 2,292 16,102 General and administrative expenses 185 1,189 Loss on sale of assets—net 4,572 4,691 Other expense 2,337 — Total 16,145 28,841

Business Dispositions (Tables)

Business Dispositions (Tables)	12 Months Ended
	Dec. 31, 2019
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Discontinued Operations	The results of the business have been reported in discontinued operations as follows: 2019 2018 2017 Revenue $ 25,040 $ 76,843 $ 112,607 Loss before income taxes from discontinued operations $ (8,253 ) $ (9,361 ) $ (25,944 ) Loss on disposal of assets held for sale (2,632 ) (14,110 ) — Income tax benefit 4,556 6,162 10,052 Loss from discontinued operations, net of income taxes $ (6,329 ) $ (17,309 ) $ (15,892 )
Schedule of Major Classes of Assets and Liabilities of Businesses Reported as Discontinued Operations	The major classes of assets and liabilities of businesses reported as discontinued operations are shown below: 2018 Assets: Accounts receivable—net $ 13,943 Contract revenues in excess of billings 9,971 Other current assets 865 Assets held for sale $ 24,779 Property and equipment—net 6,612 Goodwill 7,000 Other intangible assets—net 372 Other assets 1,699 Reserve for loss on disposal (14,110 ) Assets held for sale—noncurrent $ 1,573 Liabilities: Accounts payable $ 8,343 Accrued expenses 4,380 Other current liabilities 1,217 Liabilities held for sale 13,940 Other liabilities 146 Liabilities held for sale—noncurrent $ 146

Nature of Business and Summar_4

Nature of Business and Summary of Significant Accounting Policies (Estimated Useful Lives By Class of Assets) (Details)	12 Months Ended
	Dec. 31, 2019
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Vehicles, Dozers, And Other Light Operating Equipment And Systems [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Vehicles, Dozers, And Other Light Operating Equipment And Systems [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Heavy Operating Equipment (Dredges And Barges) [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Heavy Operating Equipment (Dredges And Barges) [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	30 years

Nature of Business and Summar_5

Nature of Business and Summary of Significant Accounting Policies (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)segment
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of operating Segments	1
Number of reportable segments	1
Number of reportable segment with goodwill	1
Accounting Standards Update 2016-02 [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Cumulative net adjustment to the beginning retained earnings balance | $	$ 2,802

Earnings Per Share - (Computati

Earnings Per Share - (Computations for Basic and Diluted Earnings (Loss) Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 55,668	$ 11,016	$ (15,368)
Loss on discontinued operations, net of income taxes	(6,329)	(17,309)	(15,892)
NET INCOME (LOSS)	$ 49,339	$ (6,293)	$ (31,260)
Weighted-average common shares outstanding — basic	63,597	62,236	61,365
Effect of stock options and restricted stock units	1,445	1,371
Weighted-average common shares outstanding — diluted	65,042	63,607	61,365
Earnings (loss) per share from continuing operations — basic	$ 0.88	$ 0.18	$ (0.25)
Earnings (loss) per share from continuing operations — diluted	$ 0.86	$ 0.17	$ (0.25)

Earnings Per Share (Narrative)

Earnings Per Share (Narrative) (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2017shares
Earnings Per Share [Abstract]
Effect of stock options and restricted stock units	716

Earnings Per Share - (Schedule

Earnings Per Share - (Schedule of Stock Options and Restricted Stock Units Excluded from Calculation of Anti-Diluted Earnings Per Share) (Details) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
Effect of stock options and restricted stock units	16	1,285	2,476

Property and Equipment (Details

Property and Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 769,737	$ 739,278
Accumulated depreciation	(395,141)	(369,415)
Property and equipment — net	374,596	369,863
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	9,992	9,992
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	5,071	5,071
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	16,299	14,087
Operating Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 738,375	$ 710,128

Property and Equipment (Narrati

Property and Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Property, Plant and Equipment [Line Items]
Depreciation	$ 37,145	$ 50,389	$ 55,962
Operating Equipment [Member]
Property, Plant and Equipment [Line Items]
Operating equipment excluded from property and equipment held for sale	$ 3,970	$ 3,537

Leases - (Schedule of Lease Cos

Leases - (Schedule of Lease Costs) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating lease cost	$ 27,259
Short-term lease cost	70,382
Total lease cost	$ 97,641

Lease (Narrative) (Details)

Lease (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Leases [Abstract]
Rent expense under long term operating lease arrangements	$ 21,160	$ 26,664

Leases - (Schedule of Maturity

Leases - (Schedule of Maturity Analysis of Operating Lease Liabilities) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Operating Lease Liabilities Payments Due Rolling Maturity [Abstract]
2020	$ 25,585
2021	21,537
2022	15,620
2023	9,752
2024	7,052
Thereafter	2,852
Minimum lease payments	82,398
Imputed interest	9,916
Present value of minimum operating lease payments	$ 72,482

Leases - (Future Minimum Operat

Leases - (Future Minimum Operating Lease Payments) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Commitments And Contingencies Disclosure [Abstract]
2019	$ 26,554
2020	22,349
2021	18,430
2022	13,552
2023	9,041
Thereafter	8,697
Total minimum operating lease payments	$ 98,623

Leases - (Schedule of Additiona

Leases - (Schedule of Additional Information Related to Leases) (Details)	Dec. 31, 2019
Lease Cost [Abstract]
Weighted average remaining lease term	4 years 2 months 12 days
Weighted average discount rate	6.70%

Leases - (Supplemental Informat

Leases - (Supplemental Information Related to Leases) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)
Leases [Abstract]
Operating cash flows from operating leases	$ (27,235)
Operating lease liabilities arising from obtaining new operating lease assets	$ 13,149

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Payroll and employee benefits	$ 16,859	$ 15,298
Insurance	15,702	13,724
Contract reserves	6,248	1,709
Interest	3,284	3,448
Income and other taxes	1,597	1,175
Fuel hedge contracts		4,710
Accrued rent		496
Other	7,535	7,791
Total accrued expenses	$ 51,225	$ 48,351

Long-Term Debt (Schedule of Lon

Long-Term Debt (Schedule of Long-Term Debt) (Details) - USD ($)	Dec. 31, 2019	Dec. 31, 2018
Debt Disclosure [Abstract]
Revolving credit facility		$ 11,500,000
8% Senior Notes	$ 322,843,000	321,950,000
Line of credit, senior note payable, equipment notes payable and senior note	322,843,000	333,450,000
Current portion of revolving credit facility	0	(11,500,000)
Long term debt	$ 322,843,000	$ 321,950,000

Long-Term Debt (Schedule of L_2

Long-Term Debt (Schedule of Long-Term Debt) (Parenthetical) (Details)	Dec. 31, 2019	May 31, 2017
8.000% Senior Notes Due in 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage	8.00%	8.00%

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	May 03, 2019	Dec. 30, 2016	Feb. 28, 2018	May 31, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Debt Instrument [Line Items]
Revolving credit facility					$ 0	$ 11,500,000
Letters of credit outstanding					35,779,000
Letter of credit remaining borrowing capacity					163,729,000
Availability under credit agreement suppressed					492,000
Net proceeds from issuance							$ 325,000,000
Amortization of deferred financing fees					$ 2,231,000	$ 3,504,000	$ 3,280,000
Senior Notes [Member]
Debt Instrument [Line Items]
Face value of senior notes issued, percentage				100.00%
Net proceeds from issuance				$ 321,653,000
Vessels and Ancillary Equipment [Member]
Debt Instrument [Line Items]
Net proceeds from sale-leaseback of a vessel yielding			$ 4,500,000
8.000% Senior Notes Due in 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				8.00%	8.00%
Debt instrument, face amount				$ 325,000,000	$ 325,000,000
Maturity date				May 15, 2022	May 15, 2022
Owned Domestic Subsidiaries Percent				100.00%
7.375% Senior Notes Due In 2019 [Member]
Debt Instrument [Line Items]
Debt instrument, interest rate, stated percentage				7.375%	7.375%	7.375%
Debt instrument, face amount				$ 275,000,000
Maturity date				Feb. 28, 2019
Redemption of notes				$ 282,638,000
Minimum [Member]
Debt Instrument [Line Items]
Fixed charge coverage ratio	1.10%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity	$ 200,000,000
Line of credit facility optional increase capacity	$ 100,000,000
Revolving credit facility, maturity date					May 3, 2024
Description of refinanced notes maturity after the maturity date					The refinanced 8% Senior Notes must have a maturity on or after the date that is 180 days after the maturity date of the Amended Credit Agreement.
Number of days prior to scheduled maturity date					91 days
Debt instrument, interest rate, stated percentage					8.00%
Revolving Credit Facility [Member] | Domestic Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Interest margin applicable	0.50%
Revolving Credit Facility [Member] | Daily LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%
Revolving Credit Facility [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Interest margin applicable	1.50%
Revolving Credit Facility [Member] | Minimum [Member] | Domestic Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	0.50%
Revolving Credit Facility [Member] | Minimum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.50%
Revolving Credit Facility [Member] | Maximum [Member] | Domestic Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	1.00%
Revolving Credit Facility [Member] | Maximum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate	2.00%
Prior Revolving Credit Agreement [Member]
Debt Instrument [Line Items]
Repayments of lines of credit		$ 250,000,000
Prior Revolving Credit Agreement [Member] | Minimum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.50%
Prior Revolving Credit Agreement [Member] | Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		1.50%
Prior Revolving Credit Agreement [Member] | Maximum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		3.00%
Prior Revolving Credit Agreement [Member] | Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt instrument, basis spread on variable rate		2.00%

Long-Term Debt (Maturities of L

Long-Term Debt (Maturities of Long-Term Debt) (Details) $ in Thousands	Dec. 31, 2019USD ($)
Debt Disclosure [Abstract]
2022	$ 325,000
Total	$ 325,000

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Fair Values of Financial Instruments and Nonfinancial Assets and Liabilities Measured at the Reporting Date) (Details) - Fuel Hedge Contracts [Member] - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 849	$ 4,710
Significant Other Observable Inputs (Level 2) [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 849	$ 4,710

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) gal in Millions	1 Months Ended	12 Months Ended
	May 31, 2017USD ($)	Dec. 31, 2019USD ($)$ / galgal	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent		80.00%
Derivative, Nonmonetary Notional Amount, Volume | gal		10.5
Fair value hedge liabilities			$ 4,710,000
Fair value hedge assets		$ 849,000
Reclassification of derivative (gains) losses to earnings—net of tax		1,458,000	$ (1,569,000)	$ (218,000)
8.000% Senior Notes Due in 2022 [Member]
Derivatives Fair Value [Line Items]
Debt instrument, face amount	$ 325,000,000	$ 325,000,000
Stated interest rate	8.00%	8.00%
Maturity date	May 15, 2022	May 15, 2022
8.000% Senior Notes Due in 2022 [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives Fair Value [Line Items]
Fair value of debt		$ 343,688,000
Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		1.79
Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		2.05

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Derivatives Fair Value [Line Items]
Asset derivatives	$ 849
Liability derivatives		$ 4,710
Other Current Assets [Member] | Derivatives Designated as Hedging Instruments [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Asset derivatives	$ 849
Accrued Liabilities [Member] | Derivatives Designated as Hedging Instruments [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Liability derivatives		$ 4,710

Fair Value Measurements (Change

Fair Value Measurements (Changes in Components of Accumulated Other Comprehensive Income (Loss)) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Fair Value Disclosures [Abstract]
Cumulative translation adjustments—net of tax	[1]		$ 1,513	$ (41)
Reclassification of derivative (gains) losses to earnings—net of tax		$ 1,458	(1,569)	(218)
Change in fair value of derivatives—net of tax		2,646	(3,756)	1,407
Net unrealized (gain) loss on derivatives—net of tax	[2]	4,104	(5,325)	1,189
Other comprehensive income (loss)—net of tax		$ 4,104	$ (3,812)	$ 1,148
[1]	Net of income tax (provision) benefit of $(1,017) and $44 for the years ended December 31, 2018 and 2017, respectively.
[2]	Net of income tax (provision) benefit of $(421), $775 and $1,048 for the years ended December 31, 2019, 2018 and 2017, respectively.

Fair Value Measurements (Adjust

Fair Value Measurements (Adjustments Reclassified from Accumulated Balances Other Comprehensive Income (Loss) to Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Derivative Instruments Gain Loss [Line Items]
Other expense	$ 317	$ (2,590)	$ 11
Costs of contract revenues	557,761	509,335	549,429
Income tax (provision) benefit	(15,253)	(5,437)	33,761
Net income (loss)	(49,339)	6,293	31,260
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments Gain Loss [Line Items]
Other expense		(2,337)
Income tax (provision) benefit		612
Net income (loss)		(1,725)
Fuel Hedge Contracts [Member] | Accumulated Gain Loss Net Cash Flow Hedge Parent [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments Gain Loss [Line Items]
Costs of contract revenues	1,975	(2,125)	(358)
Income tax (provision) benefit	517	(556)	140
Net income (loss)	$ 1,458	$ (1,569)	$ (218)

Income Taxes (Income Tax Provis

Income Taxes (Income Tax Provision (Benefit) from Continuing and Discontinuing Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Income tax provision (benefit) from continuing operations	$ 15,253	$ 5,437	$ (33,761)
Income tax benefit from discontinued operations	(4,556)	(6,162)	(10,052)
Income tax provision (benefit)	$ 10,697	$ (725)	$ (43,813)

Income Taxes (Income (Loss) fro

Income Taxes (Income (Loss) from Continuing Operations before Income Tax from Domestic and Foreign Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Domestic operations	$ 89,344	$ 26,878	$ (12,263)
Foreign operations	(18,423)	(10,425)	(36,866)
Total income (loss) from continuing operations before income tax	$ 70,921	$ 16,453	$ (49,129)

Income Taxes (Provision (Benefi

Income Taxes (Provision (Benefit) For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Current federal tax expense (benefit)			$ (248)
Deferred federal tax expense (benefit)	$ 14,052	$ 3,702	(31,957)
Current state tax expense (benefit)	212	48	29
Deferred state tax expense (benefit)	989	1,687	(1,598)
Current foreign tax expense (benefit)			13
Income tax provision (benefit)	$ 15,253	$ 5,437	$ (33,761)

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Operating Loss Carryforwards [Line Items]
U.S. federal statutory income tax rate	21.00%	21.00%	35.00%
Reduction in net deferred tax liabilities			$ 15,720,000
Increase (decrease) in valuation allowance	$ (3,000)	$ 116,000	1,152,000
Operating loss carryforwards, subject to expiration	2,407,000
Operating loss carryforwards, subject to carry forward indefinitely	4,370,000
Interest and penalties recorded	0	71,000	$ 53,000
Deferred tax assets valuation allowance	3,495,000	4,786,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Loss carryforwards for federal income tax purposes	137,100,000	168,650,000
Deferred tax assets valuation allowance	$ 0	0
Domestic Tax Authority [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2034
Domestic Tax Authority [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2037
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Loss carryforwards for federal income tax purposes	$ 223,634,000	190,901,000
State and Local Jurisdiction [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2023
State and Local Jurisdiction [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year	2029
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Loss carryforwards for federal income tax purposes	$ 6,777,000	9,533,000
Valuation allowance for net operating loss carryforwards	$ 1,717,000	$ 2,338,000
Foreign Tax Authority [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year		2019
Foreign Tax Authority [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards expiration year		2029

Income Taxes (Income Tax Prov_2

Income Taxes (Income Tax Provision (Benefit) Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Tax provision (benefit) at statutory U.S. federal income tax rate	$ 14,893	$ 3,455	$ (17,194)
State income tax — net of federal income tax benefit	3,049	937	(1,746)
Impact of Tax Cuts and Job Act			(15,720)
Change in state law regarding NOL carryforwards		658
Change in deferred state tax rate	(1,835)
Stock based compensation	(1,266)	(8)
Nondeductible officer compensation	1,021	201
Research and development tax credits	(452)	(218)	(170)
Changes in unrecognized tax benefits	(56)	14	10
Changes in valuation allowance	(3)	116	1,152
Other	(98)	282	(93)
Income tax provision (benefit)	$ 15,253	$ 5,437	$ (33,761)

Income Taxes (Reconciliation of

Income Taxes (Reconciliation of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Unrecognized tax benefits — January 1	$ 157	$ 157	$ 157
Gross increases — tax positions in prior period
Gross decreases — tax positions in prior period	$ (157)
Unrecognized tax benefits — December 31,		$ 157	$ 157

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Operating lease assets	$ 18,301
Accrued liabilities	7,426	$ 9,287
Federal NOLs	28,791	35,417
Foreign NOLs	1,717	2,338
State NOLs	9,505	10,796
Tax credit carryforwards	2,620	2,159
Charitable contribution	66	910
Valuation allowance	(3,495)	(4,786)
Total deferred tax assets	64,931	56,121
Depreciation and amortization	(82,115)	(78,967)
Operating lease liabilities	18,334
Other liabilities	(222)
Total deferred tax liabilities	(100,671)	(78,967)
Net noncurrent deferred tax liabilities	$ (35,740)	$ (22,846)

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) $ in Thousands	May 11, 2017	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense		$ 6,908	$ 4,643	$ 2,917
Total unrecognized compensation cost related to non-vested RSUs		4,984
Amount related to shares used for tax withholding obligations		$ 5,008	$ 1,205
Annual retainer per non-employee director, percentage paid in cash		50.00%
Annual retainer per non-employee director, percentage paid in common stock		50.00%
Shares of common stock received by employee directors		78,000	156,000	207,000
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights		RSUs can either vest in equal portions over the three year vesting period or vest in one installment on the third anniversary of the grant date.
Vesting period		3 years
Total unrecognized compensation cost, weighted-average period of recognition		1 year 6 months
Non Qualified Stock Options (NQSO) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting rights		The option awards generally vest in three equal annual installments commencing on the first anniversary of the grant date
Exercise period		10 years
Awards granted in period		0	0	0
Aggregate intrinsic value of stock options exercised		$ 2,534	$ 116	$ 6
Employees and Directors [Member] | 2017 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation arrangement by share-based payment award, number of shares available for grant	3,300,000
Employees and Directors [Member] | 2007 Long-Term Incentive Plan [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Underlying equity awards issued	1,700,000
Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer per non-employee director		$ 155
Chairman of the Board [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional annual retainer paid to non-employee director			$ 100
Additional percentage of annual retainer paid to non-employee director in common stock		100.00%

Share-Based Compensation (Summa

Share-Based Compensation (Summary of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding as of January 1, 2019 | shares	1,160
Exercised | shares	(650)
Forfeited or Expired | shares	(6)
Outstanding as of December 31, 2019 | shares	504
Vested at December 31, 2019 | shares	504
Weighted average exercise price outstanding as of January 1, 2019 | $ / shares	$ 6.52
Weighted average exercise price, exercised | $ / shares	6.24
Weighted average exercise price, forfeited or expired | $ / shares	6.85
Weighted average exercise price outstanding as of December 31, 2019 | $ / shares	6.87
Weighted average exercise price, vested at December 31, 2019 | $ / shares	$ 6.87
Weighted average remaining contractual term, outstanding at December 31, 2019	2 years 10 months 24 days
Weighted average remaining contractual term, vested as of December 31, 2019	2 years 10 months 24 days
Aggregate intrinsic value, outstanding as of December 31, 2019 | $	$ 2,250
Aggregate intrinsic value, vested at December 31, 2019 | $	$ 2,250

Share-Based Compensation (Sum_2

Share-Based Compensation (Summary of Non-Vested Restricted Stock Units) (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2019$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding as of January 1, 2019 | shares	2,987
Options granted | shares	587
Options vested | shares	(1,396)
Options forfeited | shares	(369)
Options outstanding as of December 31, 2019 | shares	1,809
Options expected to vest at December 31, 2019 | shares	1,670
Weighted-average grant-date fair value as of January 1, 2019 | $ / shares	$ 4.87
Weighted-average grant-date fair value, granted | $ / shares	8.64
Weighted-average grant-date fair value, vested | $ / shares	4.56
Weighted-average grant-date fair value, forfeited | $ / shares	6.49
Weighted-average grant-date fair value as of December 31, 2019 | $ / shares	6
Weighted-average grant-date fair value, expected to vest at December 31, 2019 | $ / shares	$ 5.88

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Revenue From Contract With Customer [Line Items]
Revenue, remaining performance obligation	$ 589,406
Percentage of performance obligation to be recognized as revenue	96.00%
Performance obligation, expected to be recognized as revenue year	2020
Remaining performance obligation, expected timing of satisfaction, year	2021
Revenue, description of timing	one year or less
Amortization on pre-contract and pre-construction costs	$ 11,468	$ 15,411
Contract revenues	711,518	620,795	$ 592,159
Long-lived assets, net book value	31,872	$ 30,601
Dredging [Member] | Use of Equipment [Member] | Federal Government [Member]
Revenue From Contract With Customer [Line Items]
Contract revenues	$ 2,103
Dredging [Member] | Sales [Member] | Geographic Concentration Risk [Member] | Middle East [Member] | Maximum [Member]
Revenue From Contract With Customer [Line Items]
Concentration risk percentage	10.00%	10.00%	10.00%
Dredging [Member] | Sales [Member] | Federal Government Agencies [Member] | Customer Concentration Risk [Member]
Revenue From Contract With Customer [Line Items]
Concentration risk percentage	81.70%	75.50%	63.40%
Dredging [Member] | Accounts Receivable [Member] | Geographic Concentration Risk [Member] | Middle East [Member]
Revenue From Contract With Customer [Line Items]
Concentration risk percentage	29.00%
Dredging [Member] | Accounts Receivable [Member] | Geographic Concentration Risk [Member] | Middle East [Member] | Maximum [Member]
Revenue From Contract With Customer [Line Items]
Concentration risk percentage		10.00%
Dredging [Member] | Accounts Receivable [Member] | Federal Government Agencies [Member] | Customer Concentration Risk [Member]
Revenue From Contract With Customer [Line Items]
Concentration risk percentage	54.60%	65.30%
Other Current and Noncurrent Assets [Member]
Revenue From Contract With Customer [Line Items]
Costs to fulfill contracts with customers recognized as an asset	$ 10,300	$ 13,129

Revenue (Summary of Type of Wor

Revenue (Summary of Type of Work, Contract Revenues) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Revenues	$ 711,518	$ 620,795	$ 592,159
Type of Work [Member] | Operating Segment [Member] | Dredging [Member]
Disaggregation Of Revenue [Line Items]
Revenues	711,518	620,795	592,159
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-U.S. [Member]
Disaggregation Of Revenue [Line Items]
Revenues	299,706	333,037	185,113
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	48,619	14,088	42,306
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Coastal Protection [Member]
Disaggregation Of Revenue [Line Items]
Revenues	182,369	175,923	191,070
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Maintenance [Member]
Disaggregation Of Revenue [Line Items]
Revenues	104,753	53,427	134,923
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Rivers & Lakes [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 76,071	$ 44,320	$ 38,747

Revenue (Summary of Type of Cus

Revenue (Summary of Type of Customer, Contract Revenues) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
Revenues	$ 711,518	$ 620,795	$ 592,159
Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	48,619	14,088	42,306
Type of Customer [Member] | Operating Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenues	711,518	620,795	592,159
Type of Customer [Member] | Operating Segment [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	581,157	468,421	375,276
Type of Customer [Member] | Operating Segment [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	71,398	93,499	145,196
Type of Customer [Member] | Operating Segment [Member] | Private [Member]
Disaggregation Of Revenue [Line Items]
Revenues	10,344	44,787	29,381
Type of Customer [Member] | Operating Segment [Member] | Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 48,619	$ 14,088	$ 42,306

Revenue (Schedule of Accounts R

Revenue (Schedule of Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Receivables [Abstract]
Completed contracts	$ 3,444	$ 8,592
Contracts in progress	9,490	48,418
Retainage	7,415	7,969
Accounts receivable, gross	20,349	64,979
Allowance for doubtful accounts	(564)	(200)
Total accounts receivable—net	$ 19,785	$ 64,779

Revenue (Components of Contract

Revenue (Components of Contracts in Progress) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings in excess of billings for contracts in progress	$ 18,546	$ 16,137
Costs and earnings in excess of billings for completed contracts	6,126	3,928
Total contract revenues in excess of billings	24,672	20,065
Current portion of contract revenues in excess of billings	22,560	17,953
Long-term contract revenues in excess of billings	2,112	2,112
Total billings in excess of contract revenues	(55,266)	(17,793)
Costs And Earnings In Excess Of Billings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	104,620	433,093
Amounts billed	(86,074)	(416,956)
Billings In Excess Of Costs And Earnings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	573,225	242,898
Amounts billed	$ (628,491)	$ (260,691)

Revenue (Summary of Gross Profi

Revenue (Summary of Gross Profit from Foreign Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Disaggregation Of Revenue [Line Items]
CONTRACT REVENUES	$ 711,518	$ 620,795	$ 592,159
Costs of contract revenues	(557,761)	(509,335)	(549,429)
GROSS PROFIT	153,757	111,460	42,730
Foreign [Member]
Disaggregation Of Revenue [Line Items]
CONTRACT REVENUES	48,619	14,088	42,306
Costs of contract revenues	(66,347)	(19,866)	(73,958)
GROSS PROFIT	$ (17,728)	$ (5,778)	$ (31,652)

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2019USD ($)item	Dec. 31, 2018USD ($)	Dec. 31, 2017USD ($)
Defined Contribution Plan Disclosure [Line Items]
Number of sponsored 401(k) plans | item	2
Expense for matching and discretionary contributions	$ 5,168	$ 5,060	$ 2,616
Contributes to various multiemployer pension plans	$ 4,517	$ 4,207	$ 4,699
Maximum [Member]
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plans collective-bargaining arrangement percentage of contributions	5.00%

Restructuring Charges (Narrativ

Restructuring Charges (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Severance expense	$ 662
Severance Costs [Member]
Restructuring Cost And Reserve [Line Items]
Estimated restructuring charge		$ 3,549
Asset Retirements [Member]
Restructuring Cost And Reserve [Line Items]
Estimated restructuring charge		32,309
Pre-contract Costs [Member]
Restructuring Cost And Reserve [Line Items]
Estimated restructuring charge		6,441
Closeout Costs [Member]
Restructuring Cost And Reserve [Line Items]
Estimated restructuring charge		$ 4,194

Restructuring Charges (Schedule

Restructuring Charges (Schedule of Restructuring Charges) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 16,145	$ 28,841
Loss on Sale of Assets - Net [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	4,572	4,691
Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	2,337	0
Dredging [Member] | Costs of Contract Revenues - Depreciation [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	6,759	6,859
Dredging [Member] | Costs of Contract Revenues - Other [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	2,292	16,102
Dredging [Member] | General and Administrative Expenses [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 185	$ 1,189

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)	Sep. 27, 2019USD ($)	Feb. 28, 2017USD ($)	Jan. 14, 2015USD ($)	Dec. 31, 2019USD ($)bbl	May 31, 2017USD ($)
Commitments And Contingencies [Line Items]
Outstanding performance bonds				$ 1,278,902,000
Revenue value remaining from outstanding performance bonds				$ 553,692,000
Proceeds from Legal Settlements			$ 5,309,000
Statutory maximum penalty per violation	$ 75
Crude Oil [Member]
Commitments And Contingencies [Line Items]
Quantity of oil spill | bbl				125
Surety Bond [Member]
Commitments And Contingencies [Line Items]
Aggregate demolition surety performance bond		$ 20,000,000
Letter of Credit [Member]
Commitments And Contingencies [Line Items]
Line of credit facility, maximum borrowing capacity					$ 20,881,000
Environmental and Infrastructure Segment [Member]
Commitments And Contingencies [Line Items]
Outstanding performance bonds				$ 17,401,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Bids bond range				$ 1,000,000
Warranty periods				1 year
Maximum [Member]
Commitments And Contingencies [Line Items]
Bids bond range				$ 10,000,000
Warranty periods				3 years

Business Dispositions (Narrativ

Business Dispositions (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended
	Sep. 30, 2019	Jun. 30, 2019
Discontinued Operations And Disposal Groups [Abstract]
Proceeds from sale of historical environmental and infrastructure business	$ 857	$ 17,500

Business Dispositions - (Schedu

Business Dispositions - (Schedule of Discontinued Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Discontinued Operation Income Loss From Discontinued Operation Disclosures [Abstract]
Revenue	$ 25,040	$ 76,843	$ 112,607
Loss before income taxes from discontinued operations	(8,253)	(9,361)	(25,944)
Loss on disposal of assets held for sale	(2,632)	(14,110)
Income tax benefit	4,556	6,162	10,052
Loss from discontinued operations, net of income taxes	$ (6,329)	$ (17,309)	$ (15,892)

Business Dispositions - (Sche_2

Business Dispositions - (Schedule of Major Classes of Assets and Liabilities of Businesses Reported as Discontinued Operations ) (Details) $ in Thousands	Dec. 31, 2018USD ($)
Assets:
Accounts receivable—net	$ 13,943
Contract revenues in excess of billings	9,971
Other current assets	865
Assets held for sale	24,779
Property and equipment—net	6,612
Goodwill	7,000
Other intangible assets—net	372
Other assets	1,699
Reserve for loss on disposal	(14,110)
Assets held for sale—noncurrent	1,573
Liabilities:
Accounts payable	8,343
Accrued expenses	4,380
Other current liabilities	1,217
Liabilities held for sale	13,940
Other liabilities	146
Liabilities held for sale—noncurrent	$ 146

Schedule II-Valuation and Qua_2

Schedule II-Valuation and Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 4,986	$ 4,294	$ 7,391
Additions	364	692	1,152
Deductions	(1,291)		(4,249)
Ending Balance	4,059	4,986	4,294
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	200		258
Additions	364	200
Deductions			(258)
Ending Balance	564	200
Valuation Allowance for Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	4,786	4,294	7,133
Additions		492	1,152
Deductions	(1,291)		(3,991)
Ending Balance	$ 3,495	$ 4,786	$ 4,294