Great Lakes Dredge & Dock (GLDD) 10-Q 2 Aug 19 2019 Q2 Quarterly report Financial data

Document and Entity Information

Document and Entity Information - shares	6 Months Ended
	Jun. 30, 2019	Jul. 26, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Jun. 30, 2019
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
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 Common Stock, Shares Outstanding		63,826,303
Entity Current Reporting Status	Yes
Entity File Number	001-33225
Entity Tax Identification Number	205336063
City Area Code	630
Local Phone Number	574-3000
Entity Address, Postal Zip Code	60523

Condensed Consolidated Balance

Condensed Consolidated Balance Sheets - USD ($)	Jun. 30, 2019	Dec. 31, 2018
CURRENT ASSETS:
Cash and cash equivalents	$ 125,575,000	$ 34,458,000
Accounts receivable—net	50,767,000	64,779,000
Contract revenues in excess of billings	31,159,000	17,953,000
Inventories	27,477,000	28,112,000
Prepaid expenses and other current assets	31,734,000	36,617,000
Assets held for sale		24,779,000
Total current assets	266,712,000	206,698,000
PROPERTY AND EQUIPMENT—Net	376,635,000	369,863,000
OPERATING LEASE ASSETS	74,684,000
GOODWILL AND OTHER INTANGIBLE ASSETS—Net	76,576,000	76,576,000
INVENTORIES—Noncurrent	63,199,000	61,264,000
OTHER	11,325,000	15,870,000
TOTAL	869,131,000	730,271,000
LIABILITIES AND EQUITY
Accounts payable	87,923,000	71,537,000
Accrued expenses	43,837,000	48,351,000
Operating lease liabilities	20,805,000
Billings in excess of contract revenues	50,610,000	17,793,000
Revolving credit facility	0	11,500,000
Liabilities held for sale		13,940,000
Total current liabilities	203,175,000	163,121,000
LONG-TERM DEBT	322,396,000	321,950,000
OPERATING LEASE LIABILITIES—Noncurrent	53,830,000
DEFERRED INCOME TAXES	33,706,000	22,846,000
OTHER	4,546,000	7,426,000
Total liabilities	617,653,000	515,343,000
COMMITMENTS AND CONTINGENCIES (Note 10)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 63,769 and 62,830 shares issued; 63,769 and 62,552 shares outstanding at June 30, 2019 and December 31, 2018, respectively.	6,000	6,000
Treasury stock, at cost		(1,433,000)
Additional paid-in capital	299,320,000	295,135,000
Accumulated deficit	(47,016,000)	(74,971,000)
Accumulated other comprehensive loss	(832,000)	(3,809,000)
Total equity	251,478,000	214,928,000
TOTAL	$ 869,131,000	$ 730,271,000

Condensed Consolidated Balanc_2

Condensed Consolidated Balance Sheets (Parenthetical) - $ / shares	Jun. 30, 2019	Dec. 31, 2018
Statement Of Financial Position [Abstract]
Common stock, par value	$ 1	$ 1
Common stock, shares authorized	90,000,000	90,000,000
Common stock, shares issued	63,769,000	62,830,000
Common stock, shares outstanding	63,769,000	62,552,000

Condensed Consolidated Statemen

Condensed Consolidated Statements of Operations - USD ($) shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Income Statement [Abstract]
Contract revenues	$ 184,811	$ 135,270	$ 377,448	$ 268,893
Type of Revenue [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
Costs of contract revenues	$ 147,325	$ 113,138	$ 290,085	$ 232,631
Type of Cost, Good or Service [Extensible List]	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember	gldd:ContractMember
Gross profit	$ 37,486	$ 22,132	$ 87,363	$ 36,262
General and administrative expenses	14,613	12,232	29,438	25,325
(Gain) loss on sale of assets—net	81	(1,057)	360	(1,256)
Operating income	22,792	10,957	57,565	12,193
Interest expense—net	(7,188)	(8,991)	(14,739)	(17,644)
Other income (expense)	123	33	295	(2,032)
Income (loss) from continuing operations before income taxes	15,727	1,999	43,121	(7,483)
Income tax (provision) benefit	(4,230)	(818)	(11,076)	1,657
Income (loss) from continuing operations	11,497	1,181	32,045	(5,826)
Loss from discontinued operations, net of income taxes	(3,251)	(2,155)	(6,631)	(4,469)
Net income (loss)	$ 8,246	$ (974)	$ 25,414	$ (10,295)
Basic earnings (loss) per share attributable to continuing operations	$ 0.18	$ 0.02	$ 0.51	$ (0.09)
Basic loss per share attributable to discontinued operations, net of tax	(0.05)	(0.04)	(0.10)	(0.08)
Basic earnings (loss) per share	$ 0.13	$ (0.02)	$ 0.41	$ (0.17)
Basic weighted average shares	63,605	62,267	63,243	62,041
Diluted earnings (loss) per share attributable to continuing operations	$ 0.18	$ 0.02	$ 0.50	$ (0.09)
Diluted loss per share attributable to discontinued operations, net of tax	(0.05)	(0.04)	(0.10)	(0.08)
Diluted earnings (loss) per share	$ 0.13	$ (0.02)	$ 0.40	$ (0.17)
Diluted weighted average shares	64,990	62,267	64,654	62,041

Condensed Consolidated Statem_2

Condensed Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)		$ 8,246	$ (974)	$ 25,414	$ (10,295)
Currency translation adjustment—net of tax	[1]		(57)		1,304
Net change in cash flow derivative hedges—net of tax	[2]	237	(127)	2,977	(861)
Other comprehensive income (loss)—net of tax		237	(184)	2,977	443
Comprehensive income (loss)		$ 8,483	$ (1,158)	$ 28,391	$ (9,852)
[1]	Net of income tax (provision) benefit of $5 and $(530) for the three and six months ended June 30, 2018 respectively.
[2]	Net of income tax benefit of $84 and income tax provision of $(689) for the three months ended June 30, 2019 and 2018, respectively. Net of income tax benefit of $1,055 and income tax provision of $(949) for the six months ended June 30, 2019 and 2018 respectively.

Condensed Consolidated Statem_3

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Statement Of Income And Comprehensive Income [Abstract]
Currency translation adjustment, tax		$ 5		$ (530)
Net change in cash flow derivative hedges, tax	$ 84	$ (689)	$ 1,055	$ (949)

Condensed Consolidated Statem_4

Condensed 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, 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	2,264			2,264
Share-based compensation, shares		72
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(1,060)			(1,060)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		486
Exercise of options and purchases from employee stock plans, value	443			443
Exercise of options and purchases from employee stock plans, shares		128
Net income (loss)	(10,295)				(10,295)
Other comprehensive income—net of tax	443					443
BALANCE - value at Jun. 30, 2018	211,514	$ 6	$ (1,433)	291,468	(78,973)	446
BALANCE - shares at Jun. 30, 2018		62,583	(278)
BALANCE - value at Mar. 31, 2018	211,502	$ 6	$ (1,433)	290,298	(77,999)	630
BALANCE - shares at Mar. 31, 2018		62,485	(278)
Share-based compensation, value	1,255			1,255
Share-based compensation, shares		32
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(124)			(124)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		56
Exercise of options and purchases from employee stock plans, value	39			39
Exercise of options and purchases from employee stock plans, shares		10
Net income (loss)	(974)				(974)
Other comprehensive income—net of tax	(184)					(184)
BALANCE - value at Jun. 30, 2018	211,514	$ 6	$ (1,433)	291,468	(78,973)	446
BALANCE - shares at Jun. 30, 2018		62,583	(278)
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	4,530			4,530
Share-based compensation, shares		45
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(2,929)			(2,929)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		554
Exercise of options and purchases from employee stock plans, value	3,756			3,756
Exercise of options and purchases from employee stock plans, shares		618
Cancellation of treasury stock			$ 1,433	(1,173)	(261)
Cancellation of treasury stock, shares		(278)	278
Net income (loss)	25,414				25,414
Other comprehensive income—net of tax	2,977					2,977
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 Mar. 31, 2019	239,277	$ 6	$ (1,433)	296,774	(55,001)	(1,069)
BALANCE - shares at Mar. 31, 2019		63,600	(278)
Share-based compensation, value	2,329			2,329
Share-based compensation, shares		14
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(741)			(741)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		101
Exercise of options and purchases from employee stock plans, value	2,130			2,130
Exercise of options and purchases from employee stock plans, shares		332
Cancellation of treasury stock			$ 1,433	(1,173)	(261)
Cancellation of treasury stock, shares		(278)	278
Net income (loss)	8,246				8,246
Other comprehensive income—net of tax	237					237
BALANCE - value at Jun. 30, 2019	$ 251,478	$ 6		$ 299,320	$ (47,016)	$ (832)
BALANCE - shares at Jun. 30, 2019		63,769

Condensed Consolidated Statem_5

Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018
OPERATING ACTIVITIES:
Net income (loss)	$ 25,414	$ (10,295)
Loss from discontinued operations, net of income taxes	(6,631)	(4,469)
Income (loss) from continuing operations	32,045	(5,826)
Adjustments to reconcile net income (loss) to net cash flows provided by operating activities:
Depreciation and amortization	18,001	26,838
Deferred income taxes	11,179	(4,434)
(Gain) loss on sale of assets	360	(1,256)
Other non-cash restructuring items		2,015
Amortization of deferred financing fees	1,941	1,769
Unrealized foreign currency gain		(201)
Share-based compensation expense	3,619	1,986
Changes in assets and liabilities:
Accounts receivable	14,012	(11,343)
Contract revenues in excess of billings	(13,207)	23,983
Inventories	(1,300)	1,083
Prepaid expenses and other current assets	870	11,604
Accounts payable and accrued expenses	10,044	(10,946)
Billings in excess of contract revenues	32,817	(3,091)
Other noncurrent assets and liabilities	1,404	(4,743)
Net cash flows provided by operating activities from continuing operations	111,785	27,438
Net cash flows used in operating activities of discontinued operations	(5,814)	(2,162)
Cash provided by operating activities	105,971	25,276
INVESTING ACTIVITIES:
Purchases of property and equipment	(24,316)	(11,754)
Proceeds from dispositions of property and equipment	5,516	9,930
Net cash flows used in investing activities of continuing operations	(18,800)	(1,824)
Net cash flows provided by investing activities of discontinued operations	17,198	13
Cash used in investing activities	(1,602)	(1,811)
FINANCING ACTIVITIES:
Deferred financing fees	(2,388)
Repayments of debt		(297)
Taxes paid on settlement of vested share awards	(2,929)	(1,060)
Exercise of options and purchases from employee stock plans	3,756	443
Borrowings under revolving loans		18,000
Repayments of revolving loans	(11,500)	(42,118)
Net cash flows used in financing activities of continuing operations	(13,061)	(25,032)
Net cash flows used in financing activities of discontinued operations	(191)	(773)
Cash used in financing activities	(13,252)	(25,805)
Effect of foreign currency exchange rates on cash and cash equivalents		26
Net increase (decrease) in cash, cash equivalents and restricted cash	91,117	(2,314)
Cash, cash equivalents and restricted cash at beginning of period	34,458	17,352
Cash, cash equivalents and restricted cash at end of period	125,575	15,038
Cash and cash equivalents	125,575	13,538
Restricted cash included in other long-term assets		1,500
Cash, cash equivalents and restricted cash at end of period	125,575	15,038
Supplemental Cash Flow Information
Cash paid for interest	12,963	16,245
Cash paid for income taxes	168	243
Non-cash Investing and Financing Activities
Property and equipment purchased but not yet paid	$ 7,760	5,220
Repayments of debt with proceeds from sale-leaseback transactions		$ 13,034

Basis of Presentation

Basis of Presentation	6 Months Ended
	Jun. 30, 2019
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, 2018. 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 June 30, 2019, and its results of operations for the three and six months ended June 30, 2019 and 2018 and cash flows for the six months ended June 30, 2019 and 2018 have been included. The Company adopted 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”) on January 1, 2019. The Financial Accounting Standards Board (“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 Company adopted ASC 842 using the package of practical expedients that allowed entities to retain the classification of lease contracts existing as of the date of adoption. Additionally, the Company has 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. Further, the Company adopted ASC 842 using the transition method under which entities initially applied ASC 842 at the adoption date and recognized 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 were not adjusted to apply ASC 842. Upon the adoption of ASC 842, the Company recorded a cumulative net adjustment of $2,802 to the beginning retained earnings balance. 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. During the second quarter of 2019, the Company entered into an agreement and completed the sale of the historical environmental & infrastructure business. The historical environmental & infrastructure segment has been retrospectively presented as discontinued operations and is no longer reflected in continuing operations. The Company performed its most recent annual test of impairment as of July 1, 2018 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 2019. 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. Recent accounting pronouncements In January 2017, the FASB issued Accounting Standard Update No. 2017-04 (“ASU 2017-04”), Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The Company does not anticipate that the adoption of ASU 2017-04 will have a material effect on the Company’s consolidated financial statements.

Earnings Per Share

Earnings Per Share	6 Months Ended
	Jun. 30, 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 are as follows: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2019 2018 2019 2018 Income (loss) from continuing operations $ 11,497 $ 1,181 $ 32,045 $ (5,826 ) Loss from discontinued operations, net of income taxes (3,251 ) (2,155 ) (6,631 ) (4,469 ) Net income (loss) 8,246 (974 ) 25,414 (10,295 ) Weighted-average common shares outstanding — basic 63,605 62,267 63,243 62,041 Effect of stock options and restricted stock units 1,385 — 1,411 — Weighted-average common shares outstanding — diluted 64,990 62,267 64,654 62,041 Earnings (loss) per share from continuing operations — basic $ 0.18 $ 0.02 $ 0.51 $ (0.09 ) Earnings (loss) per share from continuing operations — diluted $ 0.18 $ 0.02 $ 0.50 $ (0.09 ) For the three and six months ended June 30, 2018, the following amounts of 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: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2018 2018 Effect of stock options and restricted stock units 429 920 For the three and six months ended June 30, 2019 and 2018 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: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2019 2018 2019 2018 Effect of stock options and restricted stock units — 1,495 33 1,524

Leases

Leases	6 Months Ended
	Jun. 30, 2019
Leases [Abstract]
Leases	3. Leases The Company leases certain operating equipment and office facilities. 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 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 three and six months ended June 30, 2019, lease costs are as follows: Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating lease cost $ 6,336 $ 12,575 Short-term lease cost 16,718 32,286 Total lease cost $ 23,054 $ 44,861 Lease terms and commitments The Company’s maturity analysis of its operating lease liabilities, recorded on the balance sheet, as of June 30, 2019 is as follows: 2019 $ 12,630 2020 22,883 2021 18,737 2022 13,290 2023 8,613 Thereafter 9,046 Minimum lease payments 85,199 Imputed interest 10,564 Present value of minimum operating lease payments $ 74,635 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 our incremental borrowing rate based on the information available at commencement date in determining the present value of lease payments. At the date of adoption, 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 June 30, 2019 is as follows: June 30, 2019 Weighted average remaining lease term 4.3 years Weighted average discount rate 6.8 % Supplemental information related to leases during the three and six months ended June 30, 2019 is as follows: Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating cash flows from operating leases $ (7,118 ) $ (13,538 ) Operating lease liabilities arising from obtaining new operating lease assets $ 3,179 $ 3,248

Accrued Expenses

Accrued Expenses	6 Months Ended
	Jun. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	4. Accrued expenses Accrued expenses at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Insurance $ 15,303 $ 13,724 Payroll and employee benefits 9,760 15,298 Contract reserves 6,142 1,709 Interest 3,282 3,448 Income and other taxes 1,082 1,175 Fuel hedge contracts 678 4,710 Other 7,590 8,287 Total accrued expenses $ 43,837 $ 48,351

Long-term Debt

Long-term Debt	6 Months Ended
	Jun. 30, 2019
Debt Disclosure [Abstract]
Long-Term Debt	5. Long-term debt 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 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 publically 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 ending 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 June 30, 2019, the Company had no borrowings on the revolver, $36,747 of letters of credit outstanding and $162,761 of availability under the Amended Credit Agreement. The availability under the Amended Credit Agreement is suppressed by $492 as of June 30, 2019 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	6 Months Ended
	Jun. 30, 2019
Fair Value Disclosures [Abstract]
Fair Value Measurements	6. 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 June 30, 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 $ 678 $ — $ 678 $ — 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 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 goal is to hedge approximately 80% of the fuel requirements for work in domestic backlog. As of June 30, 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 June 2020. As of June 30, 2019, there were 8.5 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted domestic fuel purchases through June 2020. Under these swap agreements, the Company will pay fixed prices ranging from $1.86 to $2.34 per gallon. At June 30, 2019 and December 31, 2018, the fair value liabilities of the fuel hedge contracts were estimated to be $678 and $4,710, respectively, and are recorded in accrued expenses. 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 six months ended June 30, 2019 were $1,186. The remaining gains and losses included in accumulated other comprehensive loss at June 30, 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 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 June 30, 2019 and December 31, 2018 is as follows: Fair Value at June 30, December 31, Balance Sheet Location 2019 2018 Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued expenses $ 678 $ 4,710 Accumulated other comprehensive income (loss) Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Cumulative translation adjustments—net of tax $ — $ (57 ) $ — $ 1,304 Derivatives: Reclassification of derivative (gains) losses to earnings—net of tax 295 (1,037 ) 1,186 (1,769 ) Change in fair value of derivatives—net of tax (58 ) 910 1,791 908 Net change in cash flow derivative hedges—net of tax 237 (127 ) 2,977 (861 ) Total other comprehensive income (loss) $ 237 $ (184 ) $ 2,977 $ 443 Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows: Three Months Ended Six Months Ended June 30, June 30, Statement of Operations Location 2019 2018 2019 2018 Derivatives: Fuel Costs of contract revenues $ 399 $ (1,404 ) $ 1,606 $ (2,396 ) Income tax (provision) benefit 104 (367 ) 420 (627 ) $ 295 $ (1,037 ) $ 1,186 $ (1,769 ) During the first quarter of 2018, the Company substantially completed the closeout of its Brazil operations. 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: Six Months Ended Statement of Operations Location June 30, 2018 Cumulative translation adjustment: Other expense $ (2,015 ) Income tax benefit 527 $ (1,487 ) 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 June 30, 2019 (see Note 5, 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 $344,110 at June 30, 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.

Share-Based Compensation

Share-Based Compensation	6 Months Ended
	Jun. 30, 2019
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	7 . 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 six months ended June 30, 2019, the Company granted 542 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 $1,619 and $1,135 for the three months ended June 30, 2019 and 2018, respectively, and $3,619 and $1,986 for the six months ended June 30, 2019 and 2018 respectively.

Revenue

Revenue	6 Months Ended
	Jun. 30, 2019
Revenue From Contract With Customer [Abstract]
Revenue	8. Revenue At June 30, 2019, the Company had $498,089 of remaining performance obligations, which the Company refers to as total backlog. Approximately 64% of the Company’s backlog will be completed in 2019 with the remaining balance expected to be completed by 2020. 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 Six Months Ended June 30, June 30, Revenues 2019 2018 2019 2018 Dredging: Capital—U.S. $ 59,406 $ 69,651 $ 152,150 $ 146,603 Capital—foreign 18,640 3,279 26,969 8,802 Coastal protection 58,195 38,121 91,938 79,982 Maintenance 30,188 19,077 59,837 26,880 Rivers & lakes 18,382 5,142 46,554 6,626 Total revenues $ 184,811 $ 135,270 $ 377,448 $ 268,893 The Company’s contract revenues by type of customer, for the periods indicated, were as follows: Three Months Ended Six Months Ended June 30, June 30, Revenues 2019 2018 2019 2018 Dredging: Federal government $ 126,804 $ 92,913 $ 296,959 $ 169,607 State and local government 36,469 23,346 50,572 69,971 Private 2,898 15,732 2,948 20,513 Foreign 18,640 3,279 26,969 8,802 Total revenues $ 184,811 $ 135,270 $ 377,448 $ 268,893 Contract balances Accounts receivable at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Completed contracts $ 6,709 $ 8,592 Contracts in progress 37,300 48,418 Retainage 6,958 7,969 50,967 64,979 Allowance for doubtful accounts (200 ) (200 ) Total accounts receivable—net $ 50,767 $ 64,779 The components of contracts in progress at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 282,443 $ 433,093 Amounts billed (258,668 ) (416,956 ) Costs and earnings in excess of billings for contracts in progress 23,775 16,137 Costs and earnings in excess of billings for completed contracts 9,496 3,928 Total contract revenues in excess of billings $ 33,271 $ 20,065 Current portion of contract revenues in excess of billings $ 31,159 $ 17,953 Long-term contract revenues in excess of billings 2,112 2,112 Total contract revenues in excess of billings $ 33,271 $ 20,065 Billings in excess of costs and earnings: Amounts billed $ (515,791 ) $ (260,691 ) Costs and earnings for contracts in progress 465,181 242,898 Total billings in excess of contract revenues $ (50,610 ) $ (17,793 ) For amounts included in billings in excess of contract revenues balance at the beginning of the year, the Company recognized nearly all of the related revenue during the six months ended June 30, 2019. At June 30, 2019 and December 31, 2018, costs to fulfill a contract with a customer recognized as an asset were $10,046 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 three and six months ended June 30, 2019 and 2018, the company amortized $2,998 and $5,749 and $3,968 and $6,465, respectively, of pre-construction costs.

Restructuring Charges

Restructuring Charges	6 Months Ended
	Jun. 30, 2019
Restructuring And Related Activities [Abstract]
Restructuring Charges	9 . 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 our extensive fleet with new and efficient dredges to best serve our 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 for restructuring charges, including amounts presented in discontinued operations, include severance of $3,549, asset retirements of $32,309, pre-contract costs of $6,441 and closeout costs of $4,194. Restructuring activities were substantially completed in 2018. Restructuring charges recognized for the above actions for the three and six months ended June 30, 2018 are summarized as follows: Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Costs of contract revenues—depreciation $ 1,676 $ 4,668 Costs of contract revenues—other (274 ) 993 General and administrative expenses (28 ) (21 ) Loss on sale of assets—net (840 ) (847 ) Other expense — 2,015 Total $ 534 $ 6,808 The Company had accrued severance expense of $41 and $662 at June 30, 2019 and December 31, 2018, respectively, which are expected to be settled in 2019. Accrued severance is included in accrued expenses.

Commitments and Contingencies

Commitments and Contingencies	6 Months Ended
	Jun. 30, 2019
Commitments And Contingencies Disclosure [Abstract]
Commitments and Contingencies	10. 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 June 30, 2019, the Company had outstanding performance bonds with a notional amount of approximately $1,249,824 of which $41,085 relates to projects from the Company’s historical environmental & infrastructure businesses. The revenue value remaining in backlog related to these projects totaled approximately $442,475. In connection with the sale of our 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 our availability under the revolving credit facility, this draw down on our letter of credit did not impact our liquidity or capital availability. Pursuant to the terms of sale of our 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. 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. Except as noted below, the Company has not accrued any amounts with respect to the below 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. 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 our 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. The Company is in estimates matter 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. In September 2018, the EPA Region informed the Company of the EPA’s intent to file an administrative complaint against the Company relating to project the Company performed at PortMiami 2013-2015, although no complaint has been filed to date. The EPA is alleging violations of Section 103 of the Marine Protection, Research, and Sanctuaries Act (“MPRSA”) and to report violations of MPRSA. In December 2018, EPA proposed a tolling agreement to provide additional time for EPA to assess the case and possible resolution. EPA and Great Lakes negotiated and executed a tolling agreement that suspended the running of any statute of limitations until May 15, 2019, and then extended that agreement through August 14, 2019. Company disagrees with the EPA on whether violation occurred and, if violation did occur, the appropriate penalty calculation.

Business Dispositions

Business Dispositions	6 Months Ended
	Jun. 30, 2019
Discontinued Operations And Disposal Groups [Abstract]
Business Dispositions	11. 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. The final purchase price amount is subject to change based on the settlement of the working capital existing at the date of disposition. The results of the historical environmental & infrastructure businesses have been reported in discontinued operations as follows: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Revenue $ 15,856 $ 15,320 $ 25,040 $ 28,290 Loss before income taxes from discontinued operations (2,044 ) (2,919 ) (6,237 ) (6,053 ) Loss on disposal of assets held for sale (2,315 ) — (2,630 ) — Income tax benefit 1,108 764 2,236 1,584 Loss from discontinued operations, net of income taxes $ (3,251 ) $ (2,155 ) $ (6,631 ) $ (4,469 ) The major classes of assets and liabilities of businesses reported as discontinued operations are shown below: December 31, 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 Operating lease assets — 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 Operating lease liabilities — Other current liabilities 1,217 Liabilities held for sale $ 13,940 Other liabilities 146 Operating lease liabilities—noncurrent — Liabilities held for sale—noncurrent $ 146

Basis of Presentation (Policies

Basis of Presentation (Policies)	6 Months Ended
	Jun. 30, 2019
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Recent Accounting Pronouncements	Recent accounting pronouncements In January 2017, the FASB issued Accounting Standard Update No. 2017-04 (“ASU 2017-04”), Intangibles—Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment The Company does not anticipate that the adoption of ASU 2017-04 will have a material effect on the Company’s consolidated financial statements.

Earnings Per Share (Tables)

Earnings Per Share (Tables)	6 Months Ended
	Jun. 30, 2019
Earnings Per Share [Abstract]
Computations for Basic and Diluted Earnings (Loss) Per Share	The computations for basic and diluted earnings (loss) per share are as follows: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2019 2018 2019 2018 Income (loss) from continuing operations $ 11,497 $ 1,181 $ 32,045 $ (5,826 ) Loss from discontinued operations, net of income taxes (3,251 ) (2,155 ) (6,631 ) (4,469 ) Net income (loss) 8,246 (974 ) 25,414 (10,295 ) Weighted-average common shares outstanding — basic 63,605 62,267 63,243 62,041 Effect of stock options and restricted stock units 1,385 — 1,411 — Weighted-average common shares outstanding — diluted 64,990 62,267 64,654 62,041 Earnings (loss) per share from continuing operations — basic $ 0.18 $ 0.02 $ 0.51 $ (0.09 ) Earnings (loss) per share from continuing operations — diluted $ 0.18 $ 0.02 $ 0.50 $ (0.09 )
Schedule of Stock Options and Restricted Stock Units Excluded from Diluted Weighted-Average Common Shares	For the three and six months ended June 30, 2018, the following amounts of 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: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2018 2018 Effect of stock options and restricted stock units 429 920
Schedule of Stock Options and Restricted Stock Units Excluded from Calculation of Anti-Diluted Earnings Per Share	For the three and six months ended June 30, 2019 and 2018 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: Three Months Ended Six Months Ended (shares in thousands) June 30, June 30, 2019 2018 2019 2018 Effect of stock options and restricted stock units — 1,495 33 1,524

Leases (Tables)

Leases (Tables)	6 Months Ended
	Jun. 30, 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 three and six months ended June 30, 2019, lease costs are as follows: Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating lease cost $ 6,336 $ 12,575 Short-term lease cost 16,718 32,286 Total lease cost $ 23,054 $ 44,861
Schedule of Maturity Analysis of Operating Lease Liabilities	The Company’s maturity analysis of its operating lease liabilities, recorded on the balance sheet, as of June 30, 2019 is as follows: 2019 $ 12,630 2020 22,883 2021 18,737 2022 13,290 2023 8,613 Thereafter 9,046 Minimum lease payments 85,199 Imputed interest 10,564 Present value of minimum operating lease payments $ 74,635
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 June 30, 2019 is as follows: June 30, 2019 Weighted average remaining lease term 4.3 years Weighted average discount rate 6.8 %
Supplemental Information Related to Leases	Supplemental information related to leases during the three and six months ended June 30, 2019 is as follows: Three Months Ended Six Months Ended June 30, 2019 June 30, 2019 Operating cash flows from operating leases $ (7,118 ) $ (13,538 ) Operating lease liabilities arising from obtaining new operating lease assets $ 3,179 $ 3,248

Accrued Expenses (Tables)

Accrued Expenses (Tables)	6 Months Ended
	Jun. 30, 2019
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Insurance $ 15,303 $ 13,724 Payroll and employee benefits 9,760 15,298 Contract reserves 6,142 1,709 Interest 3,282 3,448 Income and other taxes 1,082 1,175 Fuel hedge contracts 678 4,710 Other 7,590 8,287 Total accrued expenses $ 43,837 $ 48,351

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	6 Months Ended
	Jun. 30, 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 June 30, 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 $ 678 $ — $ 678 $ — 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 June 30, 2019 and December 31, 2018 is as follows: Fair Value at June 30, December 31, Balance Sheet Location 2019 2018 Liability derivatives: Derivatives designated as hedging instruments Fuel hedge contracts Accrued expenses $ 678 $ 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: Three Months Ended Six Months Ended June 30, June 30, 2019 2018 2019 2018 Cumulative translation adjustments—net of tax $ — $ (57 ) $ — $ 1,304 Derivatives: Reclassification of derivative (gains) losses to earnings—net of tax 295 (1,037 ) 1,186 (1,769 ) Change in fair value of derivatives—net of tax (58 ) 910 1,791 908 Net change in cash flow derivative hedges—net of tax 237 (127 ) 2,977 (861 ) Total other comprehensive income (loss) $ 237 $ (184 ) $ 2,977 $ 443
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 Six Months Ended June 30, June 30, Statement of Operations Location 2019 2018 2019 2018 Derivatives: Fuel Costs of contract revenues $ 399 $ (1,404 ) $ 1,606 $ (2,396 ) Income tax (provision) benefit 104 (367 ) 420 (627 ) $ 295 $ (1,037 ) $ 1,186 $ (1,769 ) Six Months Ended Statement of Operations Location June 30, 2018 Cumulative translation adjustment: Other expense $ (2,015 ) Income tax benefit 527 $ (1,487 )

Revenue (Tables)

Revenue (Tables)	6 Months Ended
	Jun. 30, 2019
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 Six Months Ended June 30, June 30, Revenues 2019 2018 2019 2018 Dredging: Capital—U.S. $ 59,406 $ 69,651 $ 152,150 $ 146,603 Capital—foreign 18,640 3,279 26,969 8,802 Coastal protection 58,195 38,121 91,938 79,982 Maintenance 30,188 19,077 59,837 26,880 Rivers & lakes 18,382 5,142 46,554 6,626 Total revenues $ 184,811 $ 135,270 $ 377,448 $ 268,893 The Company’s contract revenues by type of customer, for the periods indicated, were as follows: Three Months Ended Six Months Ended June 30, June 30, Revenues 2019 2018 2019 2018 Dredging: Federal government $ 126,804 $ 92,913 $ 296,959 $ 169,607 State and local government 36,469 23,346 50,572 69,971 Private 2,898 15,732 2,948 20,513 Foreign 18,640 3,279 26,969 8,802 Total revenues $ 184,811 $ 135,270 $ 377,448 $ 268,893
Schedule of Accounts Receivable	Accounts receivable at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Completed contracts $ 6,709 $ 8,592 Contracts in progress 37,300 48,418 Retainage 6,958 7,969 50,967 64,979 Allowance for doubtful accounts (200 ) (200 ) Total accounts receivable—net $ 50,767 $ 64,779
Components of Contracts in Progress	The components of contracts in progress at June 30, 2019 and December 31, 2018 are as follows: June 30, December 31, 2019 2018 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 282,443 $ 433,093 Amounts billed (258,668 ) (416,956 ) Costs and earnings in excess of billings for contracts in progress 23,775 16,137 Costs and earnings in excess of billings for completed contracts 9,496 3,928 Total contract revenues in excess of billings $ 33,271 $ 20,065 Current portion of contract revenues in excess of billings $ 31,159 $ 17,953 Long-term contract revenues in excess of billings 2,112 2,112 Total contract revenues in excess of billings $ 33,271 $ 20,065 Billings in excess of costs and earnings: Amounts billed $ (515,791 ) $ (260,691 ) Costs and earnings for contracts in progress 465,181 242,898 Total billings in excess of contract revenues $ (50,610 ) $ (17,793 )

Restructuring charges (Tables)

Restructuring charges (Tables)	6 Months Ended
	Jun. 30, 2019
Restructuring And Related Activities [Abstract]
Schedule of Restructuring Charges	Restructuring charges recognized for the above actions for the three and six months ended June 30, 2018 are summarized as follows: Three Months Ended Six Months Ended June 30, 2018 June 30, 2018 Costs of contract revenues—depreciation $ 1,676 $ 4,668 Costs of contract revenues—other (274 ) 993 General and administrative expenses (28 ) (21 ) Loss on sale of assets—net (840 ) (847 ) Other expense — 2,015 Total $ 534 $ 6,808

Business Dispositions (Tables)

Business Dispositions (Tables)	6 Months Ended
	Jun. 30, 2019
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 Six Months Ended June 30, June 30, 2019 2018 2019 2018 Revenue $ 15,856 $ 15,320 $ 25,040 $ 28,290 Loss before income taxes from discontinued operations (2,044 ) (2,919 ) (6,237 ) (6,053 ) Loss on disposal of assets held for sale (2,315 ) — (2,630 ) — Income tax benefit 1,108 764 2,236 1,584 Loss from discontinued operations, net of income taxes $ (3,251 ) $ (2,155 ) $ (6,631 ) $ (4,469 )
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: December 31, 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 Operating lease assets — 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 Operating lease liabilities — Other current liabilities 1,217 Liabilities held for sale $ 13,940 Other liabilities 146 Operating lease liabilities—noncurrent — Liabilities held for sale—noncurrent $ 146

Basis of Presentation (Narrativ

Basis of Presentation (Narrative) (Details) $ in Thousands	6 Months Ended
	Jun. 30, 2019segment	Jan. 01, 2019USD ($)
Organization Consolidation and Presentation [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]
Organization Consolidation and Presentation [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	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ 11,497	$ 1,181	$ 32,045	$ (5,826)
Loss from discontinued operations, net of income taxes	(3,251)	(2,155)	(6,631)	(4,469)
Net income (loss)	$ 8,246	$ (974)	$ 25,414	$ (10,295)
Weighted-average common shares outstanding — basic	63,605	62,267	63,243	62,041
Effect of stock options and restricted stock units	1,385		1,411
Weighted-average common shares outstanding — diluted	64,990	62,267	64,654	62,041
Earnings (loss) per share from continuing operations — basic	$ 0.18	$ 0.02	$ 0.51	$ (0.09)
Earnings (loss) per share from continuing operations — diluted	$ 0.18	$ 0.02	$ 0.50	$ (0.09)

Earnings Per Share - (Schedule

Earnings Per Share - (Schedule of Stock Options and Restricted Stock Units Excluded from Diluted Weighted-Average Common Shares) (Details) - shares shares in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Earnings Per Share [Abstract]
Effect of stock options and restricted stock units	429	920

Earnings Per Share - (Schedul_2

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	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Earnings Per Share [Abstract]
Effect of stock options and restricted stock units	1,495	33	1,524

Leases - (Schedule of Lease Cos

Leases - (Schedule of Lease Costs) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating lease cost	$ 6,336	$ 12,575
Short-term lease cost	16,718	32,286
Total lease cost	$ 23,054	$ 44,861

Leases - (Schedule of Maturity

Leases - (Schedule of Maturity Analysis of Operating Lease Liabilities) (Details) $ in Thousands	Jun. 30, 2019USD ($)
Operating Lease Liabilities Payments Due Rolling Maturity [Abstract]
2019	$ 12,630
2020	22,883
2021	18,737
2022	13,290
2023	8,613
Thereafter	9,046
Minimum lease payments	85,199
Imputed interest	10,564
Present value of minimum operating lease payments	$ 74,635

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)	Jun. 30, 2019
Lease Cost [Abstract]
Weighted average remaining lease term	4 years 3 months 18 days
Weighted average discount rate	6.80%

Leases - (Supplemental Informat

Leases - (Supplemental Information Related to Leases) (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
	Jun. 30, 2019	Jun. 30, 2019
Leases [Abstract]
Operating cash flows from operating leases	$ (7,118)	$ (13,538)
Operating lease liabilities arising from obtaining new operating lease assets	$ 3,179	$ 3,248

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Payables And Accruals [Abstract]
Insurance	$ 15,303	$ 13,724
Payroll and employee benefits	9,760	15,298
Contract reserves	6,142	1,709
Interest	3,282	3,448
Income and other taxes	1,082	1,175
Fuel hedge contracts	678	4,710
Other	7,590	8,287
Total accrued expenses	$ 43,837	$ 48,351

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	May 03, 2019	May 31, 2017	Jun. 30, 2019	Dec. 31, 2018
Debt Instrument [Line Items]
Revolving credit facility			$ 0	$ 11,500,000
Letters of credit outstanding			36,747,000
Letter of credit remaining borrowing capacity			162,761,000
Availability under credit agreement suppressed			$ 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%
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 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
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%

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	Jun. 30, 2019	Dec. 31, 2018
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 678	$ 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)	$ 678	$ 4,710

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) gal in Millions	1 Months Ended	3 Months Ended		6 Months Ended
	May 31, 2017USD ($)	Jun. 30, 2019USD ($)$ / gal	Jun. 30, 2018USD ($)	Jun. 30, 2019USD ($)$ / galgal	Jun. 30, 2018USD ($)	Dec. 31, 2018USD ($)
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent				80.00%
Derivative, Nonmonetary Notional Amount, Volume | gal				8.5
Fair value hedge liabilities		$ 678,000		$ 678,000		$ 4,710,000
Reclassification of derivative gains (losses) to earnings—net of tax		(295,000)	$ 1,037,000	(1,186,000)	$ 1,769,000
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		$ 344,110,000		$ 344,110,000
Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		1.86		1.86
Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		2.34		2.34

Fair Value Measurements (Sche_2

Fair Value Measurements (Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Derivatives Fair Value [Line Items]
Liability derivatives	$ 678	$ 4,710
Accrued Expenses [Member] | Derivatives Designated as Hedging Instruments [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Liability derivatives	$ 678	$ 4,710

Fair Value Measurements (Change

Fair Value Measurements (Changes in Components of Accumulated Other Comprehensive Income (Loss) (Details) - USD ($) $ in Thousands		3 Months Ended		6 Months Ended
		Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Fair Value Disclosures [Abstract]
Cumulative translation adjustments—net of tax	[1]		$ (57)		$ 1,304
Reclassification of derivative (gains) losses to earnings—net of tax		$ 295	(1,037)	$ 1,186	(1,769)
Change in fair value of derivatives—net of tax		(58)	910	1,791	908
Net change in cash flow derivative hedges—net of tax	[2]	237	(127)	2,977	(861)
Other comprehensive income—net of tax		$ 237	$ (184)	$ 2,977	$ 443
[1]	Net of income tax (provision) benefit of $5 and $(530) for the three and six months ended June 30, 2018 respectively.
[2]	Net of income tax benefit of $84 and income tax provision of $(689) for the three months ended June 30, 2019 and 2018, respectively. Net of income tax benefit of $1,055 and income tax provision of $(949) for the six months ended June 30, 2019 and 2018 respectively.

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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Derivative Instruments Gain Loss [Line Items]
Other expense	$ 123	$ 33	$ 295	$ (2,032)
Costs of contract revenues	147,325	113,138	290,085	232,631
Income tax (provision) benefit	(4,230)	(818)	(11,076)	1,657
Net income (loss)	(8,246)	974	(25,414)	10,295
Accumulated Foreign Currency Adjustment Attributable to Parent [Member] | Reclassification Out of Accumulated Other Comprehensive Income [Member]
Derivative Instruments Gain Loss [Line Items]
Other expense				(2,015)
Income tax (provision) benefit				527
Net income (loss)				(1,487)
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	399	(1,404)	1,606	(2,396)
Income tax (provision) benefit	104	(367)	420	(627)
Net income (loss)	$ 295	$ (1,037)	$ 1,186	$ (1,769)

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) shares in Thousands, $ in Thousands	May 11, 2017	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Restricted stock units				542
Share-based compensation expense		$ 1,619	$ 1,135	$ 3,619	$ 1,986
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		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018	Dec. 31, 2018
Revenue From Contract With Customer [Line Items]
Revenue, remaining performance obligation	$ 498,089		$ 498,089
Percentage of performance obligation to be recognized as revenue			64.00%
Performance obligation, expected to be recognized as revenue year			2019
Remaining performance obligation, expected timing of satisfaction, year	2020		2020
Amortization on pre-construction costs	$ 2,998	$ 3,968	$ 5,749	$ 6,465
Other Current and Noncurrent Assets [Member]
Revenue From Contract With Customer [Line Items]
Costs to fulfill a contract with customer recognized as an asset	$ 10,046		$ 10,046		$ 13,129

Revenue (Summary of Contract Re

Revenue (Summary of Contract Revenues by Type of Work) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 184,811	$ 135,270	$ 377,448	$ 268,893
Type of Work [Member] | Operating Segment [Member] | Dredging [Member]
Disaggregation Of Revenue [Line Items]
Revenues	184,811	135,270	377,448	268,893
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-U.S. [Member]
Disaggregation Of Revenue [Line Items]
Revenues	59,406	69,651	152,150	146,603
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Capital-Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	18,640	3,279	26,969	8,802
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Coastal Protection [Member]
Disaggregation Of Revenue [Line Items]
Revenues	58,195	38,121	91,938	79,982
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Maintenance [Member]
Disaggregation Of Revenue [Line Items]
Revenues	30,188	19,077	59,837	26,880
Type of Work [Member] | Operating Segment [Member] | Dredging [Member] | Rivers & Lakes [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 18,382	$ 5,142	$ 46,554	$ 6,626

Revenue (Summary of Contract _2

Revenue (Summary of Contract Revenues by Type of Customer) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Disaggregation Of Revenue [Line Items]
Revenues	$ 184,811	$ 135,270	$ 377,448	$ 268,893
Type of Customer [Member] | Operating Segment [Member] | Dredging [Member]
Disaggregation Of Revenue [Line Items]
Revenues	184,811	135,270	377,448	268,893
Type of Customer [Member] | Operating Segment [Member] | Dredging [Member] | Federal Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	126,804	92,913	296,959	169,607
Type of Customer [Member] | Operating Segment [Member] | Dredging [Member] | State and Local Government [Member]
Disaggregation Of Revenue [Line Items]
Revenues	36,469	23,346	50,572	69,971
Type of Customer [Member] | Operating Segment [Member] | Dredging [Member] | Private [Member]
Disaggregation Of Revenue [Line Items]
Revenues	2,898	15,732	2,948	20,513
Type of Customer [Member] | Operating Segment [Member] | Dredging [Member] | Foreign [Member]
Disaggregation Of Revenue [Line Items]
Revenues	$ 18,640	$ 3,279	$ 26,969	$ 8,802

Revenue (Schedule of Accounts R

Revenue (Schedule of Accounts Receivable) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Receivables [Abstract]
Completed contracts	$ 6,709	$ 8,592
Contracts in progress	37,300	48,418
Retainage	6,958	7,969
Accounts receivable, gross	50,967	64,979
Allowance for doubtful accounts	(200)	(200)
Total accounts receivable—net	$ 50,767	$ 64,779

Revenue (Components of Contract

Revenue (Components of Contracts in Progress) (Details) - USD ($) $ in Thousands	Jun. 30, 2019	Dec. 31, 2018
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings in excess of billings for contracts in progress	$ 23,775	$ 16,137
Costs and earnings in excess of billings for completed contracts	9,496	3,928
Total contract revenues in excess of billings	33,271	20,065
Contract revenues in excess of billings	31,159	17,953
Long-term contract revenues in excess of billings	2,112	2,112
Total billings in excess of contract revenues	(50,610)	(17,793)
Costs And Earnings In Excess Of Billings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	282,443	433,093
Amounts billed	(258,668)	(416,956)
Billings In Excess Of Costs And Earnings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	465,181	242,898
Amounts billed	$ (515,791)	$ (260,691)

Restructuring Charges (Narrativ

Restructuring Charges (Narrative) (Details) - USD ($) $ in Thousands	6 Months Ended	12 Months Ended
	Jun. 30, 2019	Dec. 31, 2018	Dec. 31, 2017
Restructuring Cost And Reserve [Line Items]
Severance expense	$ 41	$ 662
Severance [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	3 Months Ended	6 Months Ended
	Jun. 30, 2018	Jun. 30, 2018
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ 534	$ 6,808
Loss on Sale of Assets - Net [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	(840)	(847)
Other Expense [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges		2,015
Dredging [Member] | Costs of Contract Revenues - Depreciation [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	1,676	4,668
Dredging [Member] | Costs of Contract Revenues - Other [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	(274)	993
Dredging [Member] | General and Administrative Expenses [Member]
Restructuring Cost And Reserve [Line Items]
Restructuring charges	$ (28)	$ (21)

Commitments and Contingencies (

Commitments and Contingencies (Narrative) (Details)	Feb. 28, 2017USD ($)	Jan. 14, 2015USD ($)	Jun. 30, 2019USD ($)bbl	May 31, 2017USD ($)
Commitments And Contingencies [Line Items]
Outstanding performance bonds			$ 1,249,824,000
Revenue value remaining from outstanding performance bonds			$ 442,475,000
Proceeds from Legal Settlements		$ 5,309,000
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			$ 41,085,000
Minimum [Member]
Commitments And Contingencies [Line Items]
Bids bond range			$ 1,000,000
Warranty periods			1 year
Loss contingency, Estimate of possible loss			$ 200,000
Maximum [Member]
Commitments And Contingencies [Line Items]
Bids bond range			$ 10,000,000
Warranty periods			3 years
Loss contingency, Estimate of possible loss			$ 250,000

Business Dispositions (Narrativ

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

Business Dispositions - (Schedu

Business Dispositions - (Schedule of Discontinued Operations) (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2019	Jun. 30, 2018	Jun. 30, 2019	Jun. 30, 2018
Discontinued Operation Income Loss From Discontinued Operation Disclosures [Abstract]
Revenue	$ 15,856	$ 15,320	$ 25,040	$ 28,290
Loss before income taxes from discontinued operations	(2,044)	(2,919)	(6,237)	(6,053)
Loss on disposal of assets held for sale	(2,315)		(2,630)
Income tax benefit	1,108	764	2,236	1,584
Loss from discontinued operations, net of income taxes	$ (3,251)	$ (2,155)	$ (6,631)	$ (4,469)

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