Great Lakes Dredge & Dock (GLDD) 10-Q 4 Nov 20 2020 Q3 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	9 Months Ended
	Sep. 30, 2020	Oct. 29, 2020
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Sep. 30, 2020
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q3
Trading Symbol	GLDD
Entity Registrant Name	Great Lakes Dredge & Dock Corporation
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	1 Parkview Plaza
Entity Address, City or Town	Oakbrook Terrace
Entity Address, State or Province	IL
Entity Common Stock, Shares Outstanding		64,970,532
Entity Current Reporting Status	Yes
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	60181
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 Quarterly Report	true
Document Transition Report	false

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
CURRENT ASSETS:
Cash and cash equivalents	$ 229,725	$ 186,995
Accounts receivable—net	47,218	19,785
Contract revenues in excess of billings	20,588	22,560
Inventories	32,980	30,189
Prepaid expenses and other current assets	34,220	41,183
Total current assets	364,731	300,712
PROPERTY AND EQUIPMENT—Net	372,847	374,596
OPERATING LEASE ASSETS	66,148	72,612
GOODWILL	76,576	76,576
INVENTORIES—Noncurrent	61,416	61,126
ASSETS HELD FOR SALE— Noncurrent	3,970	3,970
OTHER	8,777	7,960
TOTAL	954,465	897,552
LIABILITIES AND EQUITY
Accounts payable	79,312	76,091
Accrued expenses	52,112	51,225
Operating lease liabilities	19,019	21,351
Billings in excess of contract revenues	38,154	55,266
Total current liabilities	188,597	203,933
LONG-TERM DEBT	323,512	322,843
OPERATING LEASE LIABILITIES—Noncurrent	47,280	51,131
DEFERRED INCOME TAXES	53,299	35,740
OTHER	8,878	4,506
Total liabilities	621,566	618,153
COMMITMENTS AND CONTINGENCIES (Note 8)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 64,645 and 64,283 shares issued and outstanding at September 30, 2020 and December 31, 2019, respectively.	6	6
Additional paid-in capital	305,070	302,189
Retained earnings (accumulated deficit)	30,335	(23,091)
Accumulated other comprehensive income (loss)	(2,512)	295
Total equity	332,899	279,399
TOTAL	$ 954,465	$ 897,552

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Sep. 30, 2020	Dec. 31, 2019
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	64,645,000	64,283,000
Common stock, shares outstanding	64,645,000	64,283,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Income Statement [Abstract]
Contract revenues	$ 175,841	$ 169,775	$ 561,456	$ 547,223
Type of Revenue [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
Costs of contract revenues	$ 139,490	$ 137,942	$ 423,615	$ 428,027
Type of Cost, Good or Service [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
Gross profit	$ 36,351	$ 31,833	$ 137,841	$ 119,196
General and administrative expenses	14,888	13,488	45,263	42,926
Proceeds from loss of use claim	(1,723)		(1,723)
(Gain) loss on sale of assets—net		(27)	(184)	333
Operating income	23,186	18,372	94,485	75,937
Interest expense—net	(6,719)	(6,335)	(20,074)	(21,074)
Other income (expense)	156	(22)	(400)	273
Income from continuing operations before income taxes	16,623	12,015	74,011	55,136
Income tax provision	(4,076)	(3,204)	(18,517)	(14,280)
Income from continuing operations	12,547	8,811	55,494	40,856
Loss from discontinued operations, net of income taxes		(859)		(7,490)
Net income	$ 12,547	$ 7,952	$ 55,494	$ 33,366
Basic earnings per share attributable to continuing operations	$ 0.19	$ 0.14	$ 0.86	$ 0.64
Basic loss per share attributable to discontinued operations, net of tax		(0.02)		(0.12)
Basic earnings per share	$ 0.19	$ 0.12	$ 0.86	$ 0.52
Basic weighted average shares	64,860	63,861	64,726	63,449
Diluted earnings per share attributable to continuing operations	$ 0.19	$ 0.14	$ 0.84	$ 0.63
Diluted loss per share attributable to discontinued operations, net of tax		(0.02)		(0.12)
Diluted earnings per share	$ 0.19	$ 0.12	$ 0.84	$ 0.51
Diluted weighted average shares	65,894	65,071	65,861	64,860

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income - USD ($) $ in Thousands		3 Months Ended		9 Months Ended
		Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net income		$ 12,547	$ 7,952	$ 55,494	$ 33,366
Net unrealized (gain) loss on derivatives—net of tax	[1]	879	(160)	(2,807)	2,817
Comprehensive income		$ 13,426	$ 7,792	$ 52,687	$ 36,183
[1]	Net of income tax (provision) benefit of $296 and $(57) for the three months ended September 30, 2020 and 2019, respectively. Net of income tax (provision) benefit of $(959) and $998 for the nine months ended September 30, 2020 and 2019 respectively.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Statement Of Income And Comprehensive Income [Abstract]
Net unrealized loss on derivatives, tax	$ 296	$ (57)	$ (959)	$ 998

Condensed Consolidated Statem_4

Condensed Consolidated Statements of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Cumulative Effect of Recent Accounting Pronouncements [Member]	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Retained Earnings (Accumulated Deficit) [Member]Cumulative Effect of Recent Accounting Pronouncements [Member]	Accumulated Other Comprehensive Income (Loss) [Member]
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)
BALANCE - value at Sep. 30, 2019	261,824	$ 2,802	$ 6		301,874	(39,064)	$ 2,802	(992)
Share-based compensation, value	6,720				6,720
Share-based compensation, shares			60
Vesting of restricted stock units and impact of shares withheld for taxes, value	(3,164)				(3,164)
Vesting of restricted stock units and impact of shares withheld for taxes, shares			605
Exercise of stock options and purchases from employee stock purchase plan, value	4,355				4,355
Exercise of stock options and purchases from employee stock purchase plan, shares			699
Cancellation of treasury stock, value				$ 1,433	(1,173)	(261)
Cancellation of treasury stock, shares			(278)	278
Net income	33,366					33,366
Other comprehensive income (loss)—net of tax	2,817							2,817
BALANCE - shares at Sep. 30, 2019			63,916
BALANCE - value at Jun. 30, 2019	251,478		$ 6		299,320	(47,016)		(832)
BALANCE - shares at Jun. 30, 2019			63,769
BALANCE - value at Sep. 30, 2019	261,824	$ 2,802	$ 6		301,874	(39,064)	$ 2,802	(992)
Share-based compensation, value	2,190				2,190
Share-based compensation, shares			15
Vesting of restricted stock units and impact of shares withheld for taxes, value	(235)				(235)
Vesting of restricted stock units and impact of shares withheld for taxes, shares			51
Exercise of stock options and purchases from employee stock purchase plan, value	599				599
Exercise of stock options and purchases from employee stock purchase plan, shares			81
Net income	7,952					7,952
Other comprehensive income (loss)—net of tax	(160)							(160)
BALANCE - shares at Sep. 30, 2019			63,916
BALANCE - value at Dec. 31, 2019	279,399		$ 6		302,189	(23,091)		295
BALANCE - shares at Dec. 31, 2019			64,283
BALANCE - value at Sep. 30, 2020	332,899		$ 6		305,070	30,335		(2,512)
Share-based compensation, value	4,891				4,891
Share-based compensation, shares			80
Vesting of restricted stock units and impact of shares withheld for taxes, value	(2,174)				(2,174)
Vesting of restricted stock units and impact of shares withheld for taxes, shares			432
Exercise of stock options and purchases from employee stock purchase plan, value	1,956				1,956
Exercise of stock options and purchases from employee stock purchase plan, shares			275
Repurchase of common stock, value	(3,860)				(1,792)	(2,068)
Repurchase of common stock, shares			(425)
Net income	55,494					55,494
Other comprehensive income (loss)—net of tax	(2,807)							(2,807)
BALANCE - shares at Sep. 30, 2020			64,645
BALANCE - value at Jun. 30, 2020	321,002		$ 6		304,531	19,856		(3,391)
BALANCE - shares at Jun. 30, 2020			64,947
BALANCE - value at Sep. 30, 2020	332,899		$ 6		305,070	30,335		(2,512)
Share-based compensation, value	1,761				1,761
Share-based compensation, shares			19
Vesting of restricted stock units and impact of shares withheld for taxes, value	(68)				(68)
Vesting of restricted stock units and impact of shares withheld for taxes, shares			20
Exercise of stock options and purchases from employee stock purchase plan, value	638				638
Exercise of stock options and purchases from employee stock purchase plan, shares			84
Repurchase of common stock, value	(3,860)				$ (1,792)	(2,068)
Repurchase of common stock, shares			(425)
Net income	12,547					$ 12,547
Other comprehensive income (loss)—net of tax	$ 879							$ 879
BALANCE - shares at Sep. 30, 2020			64,645

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
OPERATING ACTIVITIES:
Net income	$ 55,494	$ 33,366
Loss from discontinued operations, net of income taxes		(7,490)
Income from continuing operations	55,494	40,856
Adjustments to reconcile net income to net cash flows provided by operating activities:
Depreciation and amortization	27,584	26,772
Deferred income taxes	18,517	14,382
(Gain) loss on sale of assets	(184)	333
Amortization of deferred financing fees	1,208	2,344
Share-based compensation expense	4,891	5,234
Changes in assets and liabilities:
Accounts receivable	(27,379)	33,736
Contract revenues in excess of billings	1,971	(7,430)
Inventories	(3,080)	(1,178)
Prepaid expenses and other current assets	6,115	454
Accounts payable and accrued expenses	4,707	13,384
Billings in excess of contract revenues	(17,112)	51,594
Other noncurrent assets and liabilities	3,264	1,556
Net cash flows provided by operating activities from continuing operations	75,996	182,037
Net cash flows used in operating activities of discontinued operations		(8,757)
Cash provided by operating activities	75,996	173,280
INVESTING ACTIVITIES:
Purchases of property and equipment	(30,124)	(37,608)
Proceeds from dispositions of property and equipment	936	5,557
Net cash flows used in investing activities of continuing operations	(29,188)	(32,051)
Net cash flows provided by investing activities of discontinued operations		18,056
Cash used in investing activities	(29,188)	(13,995)
FINANCING ACTIVITIES:
Deferred financing fees		(2,388)
Taxes paid on settlement of vested share awards	(2,174)	(3,164)
Exercise of options and purchases from employee stock plans	1,956	4,355
Repurchase of common stock	(3,860)
Repayments of revolving loans		(11,500)
Net cash flows used in financing activities of continuing operations	(4,078)	(12,697)
Net cash flows used in financing activities of discontinued operations		(191)
Cash used in financing activities	(4,078)	(12,888)
Net increase in cash, cash equivalents and restricted cash	42,730	146,397
Cash, cash equivalents and restricted cash at beginning of period	186,995	34,458
Cash, cash equivalents and restricted cash at end of period	229,725	180,855
Supplemental Cash Flow Information
Cash paid for interest	12,659	12,396
Cash paid for income taxes	385	344
Non-cash Investing and Financing Activities
Property and equipment purchased but not yet paid	$ 2,958	$ 4,455

Basis of Presentation

Basis of Presentation	9 Months Ended
	Sep. 30, 2020
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Basis of Presentation	1. Basis of presentation The unaudited condensed consolidated financial statements and notes herein should be read in conjunction with the audited consolidated financial statements of Great Lakes Dredge & Dock Corporation and Subsidiaries (the “Company” or “Great Lakes”) and the notes thereto, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2019. The condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to the SEC’s rules and regulations, although management believes that the disclosures are adequate and make the information presented not misleading. In the opinion of management, all adjustments, which are of a normal and recurring nature (except as otherwise noted), that are necessary to present fairly the Company’s financial position as of September 30, 2020 and December 31, 2019, and its results of operations for the three and nine months ended September 30, 2020 and 2019 and cash flows for the nine months ended September 30, 2020 and 2019 have been included. On March 27, 2020, the U.S. government enacted the Coronavirus Aid, Relief and Economic Security Act (the “CARES Act”). The CARES Act is an emergency economic stimulus package in response to the coronavirus (COVID-19) pandemic which, among other things, includes various tax provisions relating to refundable payroll tax credits, deferment of the employer side of certain payroll taxes and social security payments, net operating loss carryback periods, alternative minimum tax credit refunds, modifications to the net interest deduction limitations and technical corrections to tax depreciation methods for qualified improvement property. The Company has elected to defer the employer side of certain payroll taxes and is continually assessing the financial impact of these tax-related changes. As of September 30, 2020, the Company has not been significantly impacted by COVID-19 but the uncertainty that surrounds this virus means that the Company must continue to monitor and assess any potential future impact on the Company’s business, financial condition and results of operations. 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 is generally hired on a project-by-project basis. Costs of contract revenues vary significantly depending on the type and location of work performed and assets utilized. The Company has one operating segment which is also the Company’s reportable segment and reporting unit of which the Company tests goodwill for impairment. The Company performed its most recent annual test of impairment as of July 1, 2020 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 2021. On August 4, 2020, the Company announced that its board of directors approved a share repurchase program, authorizing, but not obligating, the repurchase of up to an aggregate amount of $75.0 million of its common stock from time to time through July 31, 2021. The condensed consolidated results of operations and comprehensive income for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year.

Earnings Per Share

Earnings Per Share	9 Months Ended
	Sep. 30, 2020
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 per share are as follows: Three Months Ended Nine Months Ended (shares in thousands) September 30, September 30, 2020 2019 2020 2019 Income from continuing operations $ 12,547 $ 8,811 $ 55,494 $ 40,856 Loss from discontinued operations, net of income taxes — (859 ) — (7,490 ) Net income $ 12,547 $ 7,952 $ 55,494 $ 33,366 Weighted-average common shares outstanding — basic 64,860 63,861 64,726 63,449 Effect of stock options and restricted stock units 1,034 1,210 1,135 1,411 Weighted-average common shares outstanding — diluted 65,894 65,071 65,861 64,860 Earnings per share from continuing operations — basic $ 0.19 $ 0.14 $ 0.86 $ 0.64 Earnings per share from continuing operations — diluted $ 0.19 $ 0.14 $ 0.84 $ 0.63

Accrued Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	3 . Accrued expenses Accrued expenses at September 30, 2020 and December 31, 2019 were as follows: September 30, December 31, 2020 2019 Insurance $ 15,512 $ 15,702 Payroll and employee benefits 10,627 16,859 Interest 9,784 3,284 Contract reserves 3,052 6,248 Fuel hedge contracts 2,917 — Income and other taxes 2,198 1,597 Other 8,022 7,535 Total accrued expenses $ 52,112 $ 51,225

Long-term Debt

Long-term Debt	9 Months Ended
	Sep. 30, 2020
Debt Disclosure [Abstract]
Long-Term Debt	4 . Long-term debt Credit agreement As of September 30, 2020 and December 31, 2019, the Company had no borrowings outstanding under our $200,000 amended and restated revolving credit and security agreement (as amended, the “Amended Credit Agreement”). There were $36,391 and $35,779 of letters of credit outstanding and $163,247 and $163,729 of availability under the Amended Credit Agreement as of September 30, 2020 and December 31, 2019, respectively. The availability under the Amended Credit Agreement is suppressed by $362 and $492 as of September 30, 2020 and December 31, 2019, respectively, as a result of certain limitations set forth in the Amended Credit Agreement. Senior Notes and subsidiary guarantors In May 2017, the Company issued $325,000 of 8.000% senior notes (“8% Senior Notes”) due May 15, 2022. The interest is paid semi-annually. 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.

Fair Value Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 2020
Fair Value Disclosures [Abstract]
Fair Value Measurements	5 . 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 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 September 30, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 2,917 $ — $ 2,917 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 849 $ — $ 849 $ — Fuel hedge contracts The Company is exposed to certain market risks, primarily commodity price risk as it relates to 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 could have an adverse impact on cash flows associated with its domestic dredging contracts. The Company’s typical goal is to hedge approximately 80% of the fuel requirements for work in domestic backlog. As of September 30, 2020, the Company was party to various swap arrangements to hedge the price of its diesel fuel purchase requirements for work in its backlog to be performed through September 2021. As of September 30, 2020, there were 11.6 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted domestic fuel purchases through September 2021. Under these swap agreements, the Company will pay fixed prices ranging from $1.12 to $2.00 per gallon. At September 30, 2020, the fair value liability of the fuel hedge contracts was estimated to be $2,917, and is recorded in accrued expenses. At December 31, 2019, the fair value asset of the fuel hedge contracts was estimated to be $849, and is recorded in prepaid expenses and other current assets. 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 nine months ended September 30, 2020 were $5,338. The remaining gains and losses included in accumulated other comprehensive loss at September 30, 2020 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 values of fuel hedges are corroborated using inputs that are readily observable in public markets; therefore, the Company determines fair value 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 September 30, 2020 and December 31, 2019 is as follows: Fair Value at September 30, December 31, Balance Sheet Location 2020 2019 Asset derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Prepaid expenses and other current assets $ — $ 849 Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued expenses $ 2,917 $ — Accumulated other comprehensive income (loss) Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Derivatives: Reclassification of derivative losses to earnings—net of tax 1,510 327 5,338 1,513 Change in fair value of derivatives—net of tax (631 ) (487 ) (8,145 ) 1,304 Total other comprehensive income (loss) $ 879 $ (160 ) $ (2,807 ) $ 2,817 Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Three Months Ended Nine Months Ended September 30, September 30, Statement of Operations Location 2020 2019 2020 2019 Derivatives: Fuel Costs of contract revenues $ 2,029 $ 443 $ 7,161 $ 2,049 Income tax benefit 519 116 1,823 536 $ 1,510 $ 327 $ 5,338 $ 1,513 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 our revolving credit agreement approximates fair value. In May 2017, the Company issued a total of $325,000 of 8% senior notes due May 15, 2022, which were outstanding at September 30, 2020 (see Note 4, Long-term debt). The 8% Senior Notes are senior unsecured obligations of the Company and its subsidiaries that guarantee the 8% Senior Notes. The fair value of the senior notes was $333,278 at September 30, 2020, 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.

Share-Based Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2020
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	6 . Share-based compensation On May 11, 2017, the Company’s stockholders approved the Great Lakes Dredge & Dock Corporation 2017 Long-Term Incentive Plan (the “Incentive Plan”), which previously had been approved by the Company’s board of directors subject to stockholder approval. The Incentive Plan permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to the Company’s 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. During the nine months ended September 30, 2020, the Company granted 790 thousand restricted stock units to certain employees. In addition, all non-employee directors on the Company’s board of directors are paid a portion of their board-related compensation in stock grants or restricted stock units. Compensation cost charged to expense related to share-based compensation arrangements was $1,761 and $1,615 for the three months ended September 30, 2020 and 2019, respectively. Compensation cost charged to expense related to share-based compensation arrangements was $4,891 and $5,234 for the nine months ended September 30, 2020 and 2019, respectively.

Revenue

Revenue	9 Months Ended
	Sep. 30, 2020
Revenue From Contract With Customer [Abstract]
Revenue	7 . Revenue At September 30, 2020, the Company had $661,281 of remaining performance obligations, which the Company refers to as total backlog. Approximately 28% of the Company’s backlog will be completed in 2020 with the remaining balance expected to be completed in 2021. Revenue by category The following series of tables presents our revenue disaggregated by several categories. Domestically, our 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 Company’s contract revenues by type of work, for the periods indicated, were as follows: Three Months Ended Nine Months Ended September 30, September 30, Revenues 2020 2019 2020 2019 Dredging: Capital—U.S. $ 98,194 $ 62,518 $ 245,183 $ 214,668 Capital—foreign 9,787 12,554 20,630 39,523 Coastal protection 29,780 41,959 165,668 133,897 Maintenance 33,453 30,074 117,806 89,911 Rivers & lakes 4,627 22,670 12,169 69,224 Total revenues $ 175,841 $ 169,775 $ 561,456 $ 547,223 The Company’s contract revenues by type of customer, for the periods indicated, were as follows: Three Months Ended Nine Months Ended September 30, September 30, Revenues 2020 2019 2020 2019 Dredging: Federal government $ 154,083 $ 134,763 $ 453,346 $ 431,722 State and local government 4,464 18,505 76,489 69,077 Private 7,507 3,953 10,991 6,901 Foreign 9,787 12,554 20,630 39,523 Total revenues $ 175,841 $ 169,775 $ 561,456 $ 547,223 Contract balances Accounts receivable at September 30, 2020 and December 31, 2019 are as follows: September 30, December 31, 2020 2019 Completed contracts $ 12,140 $ 3,444 Contracts in progress 27,083 9,490 Retainage 8,559 7,415 47,782 20,349 Allowance for doubtful accounts (564 ) (564 ) Total accounts receivable—net $ 47,218 $ 19,785 The components of contracts in progress at September 30, 2020 and December 31, 2019 are as follows: September 30, December 31, 2020 2019 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 324,464 $ 104,620 Amounts billed (307,991 ) (86,074 ) Costs and earnings in excess of billings for contracts in progress 16,473 18,546 Costs and earnings in excess of billings for completed contracts 6,174 6,126 Total contract revenues in excess of billings $ 22,647 $ 24,672 Current portion of contract revenues in excess of billings $ 20,588 $ 22,560 Long-term contract revenues in excess of billings 2,059 2,112 Total contract revenues in excess of billings $ 22,647 $ 24,672 Billings in excess of costs and earnings: Amounts billed $ (330,853 ) $ (628,491 ) Costs and earnings for contracts in progress 292,699 573,225 Total billings in excess of contract revenues $ (38,154 ) $ (55,266 ) At September 30, 2020 and December 31, 2019, costs to fulfill a contract with a customer recognized as an asset were $8,848 and $10,300, respectively, and are recorded in other current assets and other noncurrent assets. These costs relate to pre-contract and pre-construction activities. During the three and nine months ended September 30, 2020 and 2019, the Company amortized $2,891 and $11,695 and $3,097 and $8,846, respectively, of pre-construction costs.

Commitments and Contingencies

Commitments and Contingencies	9 Months Ended
	Sep. 30, 2020
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	8 . 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, under which the Company can obtain performance, bid and payment bonds. The Company also has outstanding bonds with Travelers Casualty, Surety Company of America and Zurich American Insurance Company (“Zurich”). Bid bonds are generally obtained for a percentage of bid value and amounts outstanding typically range from $1,000 to $10,000. At September 30, 2020, the Company had outstanding performance bonds with a notional amount of approximately $1,254,315 of which $17,401 relates to projects from the Company’s historical environmental & infrastructure businesses. The revenue value remaining in backlog related to these projects totaled approximately $593,142. 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 commitment from the buyer for losses resulting from the bonding arrangement. In April 2020, the Court granted the Company’s motion for entry of final judgment in the amount of $21,934 based upon the buyer’s default of its obligations to indemnify the Company for losses resulting from the bonding arrangement. In May 2020, the Court entered that final judgment, and in June 2020, Defendants filed a notice of appeal from that judgment. 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. 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 160 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 has calculated and proposed that the administrative court issue a penalty in the total amount of $973. 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. Lease obligations The Company leases certain operating equipment and office facilities under long-term operating leases expiring at various dates through 2026. 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.

Business Dispositions

Business Dispositions	9 Months Ended
	Sep. 30, 2020
Discontinued Operations And Disposal Groups [Abstract]
Business Dispositions	9 . Business dispositions Discontinued operations During the second quarter of 2019, the Company entered into an agreement and 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 historical environmental & infrastructure businesses have been reported in discontinued operations as follows: Three Months Ended Nine Months Ended September 30, September 30, 2019 2019 Revenue $ — $ 25,040 Loss before income taxes from discontinued operations (1,184 ) (7,421 ) Loss on disposal of assets held for sale (2 ) (2,632 ) Income tax benefit 327 2,563 Loss from discontinued operations, net of income taxes $ (859 ) $ (7,490 )

Earnings Per Share (Tables)

Earnings Per Share (Tables)	9 Months Ended
	Sep. 30, 2020
Earnings Per Share [Abstract]
Computations for Basic and Diluted Earnings Per Share	The computations for basic and diluted earnings per share are as follows: Three Months Ended Nine Months Ended (shares in thousands) September 30, September 30, 2020 2019 2020 2019 Income from continuing operations $ 12,547 $ 8,811 $ 55,494 $ 40,856 Loss from discontinued operations, net of income taxes — (859 ) — (7,490 ) Net income $ 12,547 $ 7,952 $ 55,494 $ 33,366 Weighted-average common shares outstanding — basic 64,860 63,861 64,726 63,449 Effect of stock options and restricted stock units 1,034 1,210 1,135 1,411 Weighted-average common shares outstanding — diluted 65,894 65,071 65,861 64,860 Earnings per share from continuing operations — basic $ 0.19 $ 0.14 $ 0.86 $ 0.64 Earnings per share from continuing operations — diluted $ 0.19 $ 0.14 $ 0.84 $ 0.63

Accrued Expenses (Tables)

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2020
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses at September 30, 2020 and December 31, 2019 were as follows: September 30, December 31, 2020 2019 Insurance $ 15,512 $ 15,702 Payroll and employee benefits 10,627 16,859 Interest 9,784 3,284 Contract reserves 3,052 6,248 Fuel hedge contracts 2,917 — Income and other taxes 2,198 1,597 Other 8,022 7,535 Total accrued expenses $ 52,112 $ 51,225

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2020
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 September 30, 2020 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 2,917 $ — $ 2,917 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2019 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 849 $ — $ 849 $ —
Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location	The fair value of the fuel hedge contracts outstanding as of September 30, 2020 and December 31, 2019 is as follows: Fair Value at September 30, December 31, Balance Sheet Location 2020 2019 Asset derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Prepaid expenses and other current assets $ — $ 849 Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued expenses $ 2,917 $ —
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: Three Months Ended Nine Months Ended September 30, September 30, 2020 2019 2020 2019 Derivatives: Reclassification of derivative losses to earnings—net of tax 1,510 327 5,338 1,513 Change in fair value of derivatives—net of tax (631 ) (487 ) (8,145 ) 1,304 Total other comprehensive income (loss) $ 879 $ (160 ) $ (2,807 ) $ 2,817
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: Three Months Ended Nine Months Ended September 30, September 30, Statement of Operations Location 2020 2019 2020 2019 Derivatives: Fuel Costs of contract revenues $ 2,029 $ 443 $ 7,161 $ 2,049 Income tax benefit 519 116 1,823 536 $ 1,510 $ 327 $ 5,338 $ 1,513

Revenue (Tables)

Revenue (Tables)	9 Months Ended
	Sep. 30, 2020
Revenue From Contract With Customer [Abstract]
Summary of Contract Revenues by Type of Work and Customer	The Company’s contract revenues by type of work, for the periods indicated, were as follows: Three Months Ended Nine Months Ended September 30, September 30, Revenues 2020 2019 2020 2019 Dredging: Capital—U.S. $ 98,194 $ 62,518 $ 245,183 $ 214,668 Capital—foreign 9,787 12,554 20,630 39,523 Coastal protection 29,780 41,959 165,668 133,897 Maintenance 33,453 30,074 117,806 89,911 Rivers & lakes 4,627 22,670 12,169 69,224 Total revenues $ 175,841 $ 169,775 $ 561,456 $ 547,223 The Company’s contract revenues by type of customer, for the periods indicated, were as follows: Three Months Ended Nine Months Ended September 30, September 30, Revenues 2020 2019 2020 2019 Dredging: Federal government $ 154,083 $ 134,763 $ 453,346 $ 431,722 State and local government 4,464 18,505 76,489 69,077 Private 7,507 3,953 10,991 6,901 Foreign 9,787 12,554 20,630 39,523 Total revenues $ 175,841 $ 169,775 $ 561,456 $ 547,223
Schedule of Accounts Receivable	Accounts receivable at September 30, 2020 and December 31, 2019 are as follows: September 30, December 31, 2020 2019 Completed contracts $ 12,140 $ 3,444 Contracts in progress 27,083 9,490 Retainage 8,559 7,415 47,782 20,349 Allowance for doubtful accounts (564 ) (564 ) Total accounts receivable—net $ 47,218 $ 19,785
Components of Contracts in Progress	The components of contracts in progress at September 30, 2020 and December 31, 2019 are as follows: September 30, December 31, 2020 2019 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 324,464 $ 104,620 Amounts billed (307,991 ) (86,074 ) Costs and earnings in excess of billings for contracts in progress 16,473 18,546 Costs and earnings in excess of billings for completed contracts 6,174 6,126 Total contract revenues in excess of billings $ 22,647 $ 24,672 Current portion of contract revenues in excess of billings $ 20,588 $ 22,560 Long-term contract revenues in excess of billings 2,059 2,112 Total contract revenues in excess of billings $ 22,647 $ 24,672 Billings in excess of costs and earnings: Amounts billed $ (330,853 ) $ (628,491 ) Costs and earnings for contracts in progress 292,699 573,225 Total billings in excess of contract revenues $ (38,154 ) $ (55,266 )

Business Dispositions (Tables)

Business Dispositions (Tables)	9 Months Ended
	Sep. 30, 2020
Discontinued Operations And Disposal Groups [Abstract]
Schedule of Discontinued Operations	The results of the historical environmental & infrastructure businesses have been reported in discontinued operations as follows: Three Months Ended Nine Months Ended September 30, September 30, 2019 2019 Revenue $ — $ 25,040 Loss before income taxes from discontinued operations (1,184 ) (7,421 ) Loss on disposal of assets held for sale (2 ) (2,632 ) Income tax benefit 327 2,563 Loss from discontinued operations, net of income taxes $ (859 ) $ (7,490 )

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details)	9 Months Ended
	Sep. 30, 2020segment	Aug. 04, 2020USD ($)
Organization Consolidation and Presentation [Line Items]
Number of operating Segments	1
Number of reportable segments	1
Number of reportable segment with goodwill	1
Common Stock [Member] | Maximum [Member]
Organization Consolidation and Presentation [Line Items]
Stock repurchase program, authorized amount | $		$ 75,000,000

Earnings Per Share - (Computati

Earnings Per Share - (Computations for Basic and Diluted Earnings Per Share) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Earnings Per Share [Abstract]
Income from continuing operations	$ 12,547	$ 8,811	$ 55,494	$ 40,856
Loss from discontinued operations, net of income taxes		(859)		(7,490)
Net income	$ 12,547	$ 7,952	$ 55,494	$ 33,366
Weighted-average common shares outstanding — basic	64,860	63,861	64,726	63,449
Effect of stock options and restricted stock units	1,034	1,210	1,135	1,411
Weighted-average common shares outstanding — diluted	65,894	65,071	65,861	64,860
Earnings per share from continuing operations — basic	$ 0.19	$ 0.14	$ 0.86	$ 0.64
Earnings per share from continuing operations — diluted	$ 0.19	$ 0.14	$ 0.84	$ 0.63

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Payables And Accruals [Abstract]
Insurance	$ 15,512	$ 15,702
Payroll and employee benefits	10,627	16,859
Interest	9,784	3,284
Contract reserves	3,052	6,248
Fuel hedge contracts	2,917
Income and other taxes	2,198	1,597
Other	8,022	7,535
Total accrued expenses	$ 52,112	$ 51,225

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	1 Months Ended
	May 31, 2017	Sep. 30, 2020	Dec. 31, 2019
Debt Instrument [Line Items]
Revolving credit facility		$ 0	$ 0
Letters of credit outstanding		36,391,000	35,779,000
Letter of credit remaining borrowing capacity		163,247,000	163,729,000
Availability under credit agreement suppressed		362,000	492,000
8.000% Senior Notes Due in 2022 [Member]
Debt Instrument [Line Items]
Debt instrument, face amount	$ 325,000,000
Debt instrument, interest rate, stated percentage	8.00%
Maturity date	May 15, 2022
Owned Domestic Subsidiaries Percent	100.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity		$ 200,000,000	$ 200,000,000

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	Sep. 30, 2020	Dec. 31, 2019
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 2,917	$ 849
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)	$ 2,917	$ 849

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) gal in Millions	1 Months Ended	3 Months Ended		9 Months Ended
	May 31, 2017USD ($)	Sep. 30, 2020USD ($)$ / gal	Sep. 30, 2019USD ($)	Sep. 30, 2020USD ($)$ / galgal	Sep. 30, 2019USD ($)	Dec. 31, 2019USD ($)
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent				80.00%
Derivative, Nonmonetary Notional Amount, Volume | gal				11.6
Fair value hedge liability		$ 2,917,000		$ 2,917,000
Fair value hedge assets						$ 849,000
Reclassification of derivative (gains) losses to earnings—net of tax		1,510,000	$ 327,000	5,338,000	$ 1,513,000
8.000% Senior Notes Due in 2022 [Member]
Derivatives Fair Value [Line Items]
Debt instrument, face amount	$ 325,000,000
Stated interest rate	8.00%
Maturity date	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		$ 333,278,000		$ 333,278,000
Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		1.12		1.12
Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		2		2
Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent				80.00%

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Derivatives Fair Value [Line Items]
Asset derivatives		$ 849
Liability derivatives	$ 2,917
Accrued Expenses [Member] | Derivatives Designated as Hedging Instruments [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Liability derivatives	$ 2,917
Prepaid Expenses and Other Current Assets [Member] | Derivatives Designated as Hedging Instruments [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Asset derivatives		$ 849

Fair Value Measurements (Change

Fair Value Measurements (Changes in Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Fair Value Disclosures [Abstract]
Reclassification of derivative losses to earnings—net of tax	$ 1,510	$ 327	$ 5,338	$ 1,513
Change in fair value of derivatives—net of tax	(631)	(487)	(8,145)	1,304
Total other comprehensive income (loss)	$ 879	$ (160)	$ (2,807)	$ 2,817

Fair Value Measurements (Adjust

Fair Value Measurements (Adjustments Reclassified from Accumulated Balances Other Comprehensive Income (Loss) to Earnings) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Derivative Instruments Gain Loss [Line Items]
Other expense	$ 156	$ (22)	$ (400)	$ 273
Costs of contract revenues	139,490	137,942	423,615	428,027
Income tax benefit	(4,076)	(3,204)	(18,517)	(14,280)
Net income (loss)	(12,547)	(7,952)	(55,494)	(33,366)
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	2,029	443	7,161	2,049
Income tax benefit	519	116	1,823	536
Net income (loss)	$ 1,510	$ 327	$ 5,338	$ 1,513

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	May 11, 2017	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units				790
Share-based compensation expense		$ 1,761	$ 1,615	$ 4,891	$ 5,234
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
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

Revenue (Narrative) (Details)

Revenue (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019	Dec. 31, 2019
Revenue From Contract With Customer [Line Items]
Revenue, remaining performance obligation	$ 661,281		$ 661,281
Percentage of performance obligation to be recognized as revenue			28.00%
Performance obligation, expected to be recognized as revenue year			2020
Remaining performance obligation, expected timing of satisfaction, year	2021		2021
Amortization on pre-construction costs	$ 2,891	$ 3,097	$ 11,695	$ 8,846
Other Current and Noncurrent Assets [Member]
Revenue From Contract With Customer [Line Items]
Costs to fulfill a contract with customer recognized as an asset	$ 8,848		$ 8,848		$ 10,300

Revenue (Summary of Contract Re

Revenue (Summary of Contract Revenues by Type of Work) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenues	$ 175,841	$ 169,775	$ 561,456	$ 547,223
Type of Work [Member] | Operating Segment [Member] | Dredging [Member]
Disaggregation Of Revenue [Line Items]
Revenues	175,841	169,775	561,456	547,223
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-U.S. [Member]
Disaggregation Of Revenue [Line Items]
Revenues	98,194	62,518	245,183	214,668
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	9,787	12,554	20,630	39,523
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Coastal Protection [Member]
Disaggregation Of Revenue [Line Items]
Revenues	29,780	41,959	165,668	133,897
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Maintenance [Member]
Disaggregation Of Revenue [Line Items]
Revenues	33,453	30,074	117,806	89,911
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Rivers & Lakes [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 4,627	$ 22,670	$ 12,169	$ 69,224

Revenue (Summary of Contract _2

Revenue (Summary of Contract Revenues by Type of Customer) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2020	Sep. 30, 2019
Disaggregation Of Revenue [Line Items]
Revenues	$ 175,841	$ 169,775	$ 561,456	$ 547,223
Type of Customer [Member] | Operating Segment [Member]
Disaggregation Of Revenue [Line Items]
Revenues	175,841	169,775	561,456	547,223
Type of Customer [Member] | Operating Segment [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	154,083	134,763	453,346	431,722
Type of Customer [Member] | Operating Segment [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	4,464	18,505	76,489	69,077
Type of Customer [Member] | Operating Segment [Member] | Private [Member]
Disaggregation Of Revenue [Line Items]
Revenues	7,507	3,953	10,991	6,901
Type of Customer [Member] | Operating Segment [Member] | Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 9,787	$ 12,554	$ 20,630	$ 39,523

Revenue (Schedule of Accounts R

Revenue (Schedule of Accounts Receivable) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Receivables [Abstract]
Completed contracts	$ 12,140	$ 3,444
Contracts in progress	27,083	9,490
Retainage	8,559	7,415
Accounts receivable, gross	47,782	20,349
Allowance for doubtful accounts	(564)	(564)
Total accounts receivable—net	$ 47,218	$ 19,785

Revenue (Components of Contract

Revenue (Components of Contracts in Progress) (Details) - USD ($) $ in Thousands	Sep. 30, 2020	Dec. 31, 2019
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings in excess of billings for contracts in progress	$ 16,473	$ 18,546
Costs and earnings in excess of billings for completed contracts	6,174	6,126
Total contract revenues in excess of billings	22,647	24,672
Current portion of contract revenues in excess of billings	20,588	22,560
Long-term contract revenues in excess of billings	2,059	2,112
Total billings in excess of contract revenues	(38,154)	(55,266)
Costs And Earnings In Excess Of Billings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	324,464	104,620
Amounts billed	(307,991)	(86,074)
Billings In Excess Of Costs And Earnings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	292,699	573,225
Amounts billed	$ (330,853)	$ (628,491)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)	Sep. 27, 2019USD ($)	Feb. 28, 2017USD ($)	Jan. 14, 2015USD ($)	Apr. 30, 2020USD ($)	Sep. 30, 2020USD ($)bbl	May 31, 2017USD ($)
Commitments And Contingencies [Line Items]
Outstanding performance bonds					$ 1,254,315,000
Revenue value remaining from outstanding performance bonds					$ 593,142,000
Proceeds from Legal Settlements			$ 5,309,000
Total penalty issued by administrative court	$ 973
Crude Oil [Member]
Commitments And Contingencies [Line Items]
Quantity of oil spill | bbl					160
Surety Bond [Member]
Commitments And Contingencies [Line Items]
Aggregate demolition surety performance bond		$ 20,000,000
Indemnification Commitment [Member]
Commitments And Contingencies [Line Items]
Aggregate demolition surety performance bond				$ 21,934,000
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	3 Months Ended	9 Months Ended
	Sep. 30, 2019	Sep. 30, 2019
Discontinued Operation Income Loss From Discontinued Operation Disclosures [Abstract]
Revenue		$ 25,040
Loss before income taxes from discontinued operations	$ (1,184)	(7,421)
Loss on disposal of assets held for sale	(2)	(2,632)
Income tax benefit	327	2,563
Loss from discontinued operations, net of income taxes	$ (859)	$ (7,490)