Great Lakes Dredge & Dock (GLDD) 10-K 29 Feb 16 2015 FY Annual report Financial data

Document And Entity Information

Document And Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2015	Feb. 19, 2016	Jun. 30, 2015
Document And Entity Information [Abstract]
Document Type	10-K
Amendment Flag	false
Document Period End Date	Dec. 31, 2015
Document Fiscal Year Focus	2,015
Document Fiscal Period Focus	FY
Trading Symbol	GLDD
Entity Registrant Name	Great Lakes Dredge & Dock CORP
Entity Central Index Key	1,372,020
Current Fiscal Year End Date	--12-31
Entity Filer Category	Accelerated Filer
Entity Common Stock, Shares Outstanding		60,431,841
Entity Public Float			$ 330,554,110
Entity Voluntary Filers	No
Entity Well-known Seasoned Issuer	No
Entity Current Reporting Status	Yes

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
CURRENT ASSETS:
Cash and cash equivalents	$ 14,184	$ 42,389
Accounts receivable—net	130,777	113,188
Contract revenues in excess of billings	81,195	82,557
Inventories	35,963	34,735
Prepaid expenses	7,924	4,708
Other current assets	59,690	64,667
Total current assets	329,733	342,244
PROPERTY AND EQUIPMENT—Net	430,210	399,445
GOODWILL	83,576	86,326
OTHER INTANGIBLE ASSETS — Net	2,428	8,963
INVENTORIES—Noncurrent	41,646	36,262
INVESTMENTS IN JOINT VENTURES	3,761	7,889
OTHER	10,271	12,105
TOTAL	901,625	893,234
CURRENT LIABILITIES:
Accounts payable	118,846	119,971
Accrued expenses	72,277	70,041
Billings in excess of contract revenues	7,061	4,639
Current portion of long term debt	7,506	5,859
Total current liabilities	205,690	200,510
7 3/8% SENIOR NOTES	274,909	274,880
REVOLVING CREDIT FACILITY	20,000
NOTES PAYABLE	54,382	49,497
DEFERRED INCOME TAXES	74,006	92,007
OTHER	20,465	20,377
Total liabilities	$ 649,452	$ 637,271
COMMITMENTS AND CONTINGENCIES (Note 13)
EQUITY:
Common stock—$.0001 par value; 90,000 authorized, 60,709 and 60,170 shares issued; 60,431 and 60,170 outstanding at December 31, 2015 and December 31, 2014, respectively.	$ 6	$ 6
Treasury stock, at cost	(1,433)
Additional paid-in capital	283,247	278,166
Accumulated deficit	(27,664)	(21,475)
Accumulated other comprehensive loss	(1,983)	(734)
Total equity	252,173	255,963
TOTAL	$ 901,625	$ 893,234

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - $ / shares	Dec. 31, 2015	Dec. 31, 2014
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	60,709,000	60,170,000
Common stock, shares outstanding	60,431,000	60,170,000

Consolidated Statements Of Oper

Consolidated Statements Of Operations - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Statement [Abstract]
CONTRACT REVENUES	$ 856,878	$ 806,831	$ 731,418
COSTS OF CONTRACT REVENUES	760,955	714,335	631,123
GROSS PROFIT	95,923	92,496	100,295
OPERATING EXPENSES:
GENERAL AND ADMINISTRATIVE EXPENSES	71,069	67,911	68,039
PROCEEDS FROM LOSS OF USE CLAIM			(13,372)
IMPAIRMENT OF GOODWILL	2,750
(GAIN) LOSS ON SALE OF ASSETS—Net	(855)	732	(5,773)
Total operating income	22,959	23,853	51,401
OTHER EXPENSE:
Interest expense—net	(24,365)	(19,967)	(21,941)
Equity in earnings (loss) of joint ventures	(6,051)	2,895	1,208
Gain on bargain purchase acquisition		2,197
Other income (expense)	(1,229)	210	(351)
Total other expense	(31,645)	(14,665)	(21,084)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES	(8,686)	9,188	30,317
INCOME TAX (PROVISION) BENEFIT	2,497	11,530	(10,460)
INCOME (LOSS) FROM CONTINUING OPERATIONS	(6,189)	20,718	19,857
Loss from discontinued operations, net of income taxes		(10,423)	(54,850)
NET INCOME (LOSS)	(6,189)	10,295	(34,993)
Net loss attributable to noncontrolling interest			632
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION	$ (6,189)	$ 10,295	$ (34,361)
Basic earnings (loss) per share attributable to income from continuing operations	$ (0.10)	$ 0.35	$ 0.33
Basic loss per share attributable to loss on discontinued operations, net of income taxes		(0.17)	(0.91)
Basic earnings (loss) per share attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$ (0.10)	$ 0.18	$ (0.58)
Basic weighted average shares	60,410	59,938	59,495
Diluted earnings (loss) per share attributable to income from continuing operations	$ (0.10)	$ 0.34	$ 0.33
Diluted loss per share attributable to loss on discontinued operations, net of income taxes		(0.17)	(0.90)
Diluted earnings (loss) per share attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$ (0.10)	$ 0.17	$ (0.57)
Diluted weighted average shares	60,410	60,522	60,101

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Income (Loss) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Net income (loss)		$ (6,189)	$ 10,295	$ (34,993)
Currency translation adjustment—net of tax	[1]	(1,249)	(62)	(397)
Net unrealized (gain) loss on derivatives—net of tax	[2]		(199)	304
Other comprehensive loss—net of tax		(1,249)	(261)	(93)
Comprehensive income (loss)		(7,438)	10,034	(35,086)
Comprehensive loss attributable to noncontrolling interests				632
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation		$ (7,438)	$ 10,034	$ (34,454)
[1]	Net of income tax benefit of $827, $41 and $261 for the years ended December 31, 2015, 2014 and 2013, respectively.
[2]	Net of income tax (provision) benefit of $(132) and $204 for the years ended December 31, 2014 and 2013, respectively.

Consolidated Statements of Com6

Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Statement Of Income And Comprehensive Income [Abstract]
Currency translation adjustment, tax	$ 827	$ 41	$ 261
Net unrealized (gain) loss on derivatives-net of tax		$ (132)	$ 204

Consolidated Statements Of Equi

Consolidated Statements Of Equity - USD ($) shares in Thousands, $ in Thousands	Total	Common Stock [Member]	Treasury Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings (Accumulated Deficit) [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]
BALANCE - value at Dec. 31, 2012	$ 273,425	$ 6		$ 271,418	$ 2,591	$ (380)	$ (210)
BALANCE - shares at Dec. 31, 2012		59,359
Share-based compensation, Value	3,251			3,251
Share-based compensation, Shares		96
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(308)			(308)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		75
Exercise of stock options and purchases from employee stock plans, Value	668			668
Exercise of stock options and purchases from employee stock plans, Shares		140
Excess income tax benefit from share-based compensation	154			154
Purchase of noncontrolling interests	(3)						(3)
Net loss	(34,993)				(34,361)		(632)
Other comprehensive loss—net of tax	(93)					(93)
BALANCE - value at Dec. 31, 2013	242,101	$ 6		275,183	(31,770)	(473)	(845)
BALANCE - shares at Dec. 31, 2013		59,670
Share-based compensation, Value	2,694			2,694
Share-based compensation, Shares		118
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(497)			(497)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		111
Exercise of stock options and purchases from employee stock plans, Value	1,568			1,568
Exercise of stock options and purchases from employee stock plans, Shares		271
Excess income tax benefit from share-based compensation	206			206
Purchase of noncontrolling interests	(143)			(988)			$ 845
Net loss	10,295				10,295
Other comprehensive loss—net of tax	(261)					(261)
BALANCE - value at Dec. 31, 2014	255,963	$ 6		278,166	(21,475)	(734)
BALANCE - shares at Dec. 31, 2014		60,170
Share-based compensation, Value	4,040			4,040
Share-based compensation, Shares		154
Vesting of restricted stock units, including impact of shares withheld for taxes, value	(267)			(267)
Vesting of restricted stock units, including impact of shares withheld for taxes, shares		115
Exercise of stock options and purchases from employee stock plans, Value	$ 1,365			1,365
Exercise of stock options and purchases from employee stock plans, Shares	86	270
Excess income tax benefit from share-based compensation	$ (57)			(57)
Purchase of treasury stock, value	(1,433)		$ (1,433)
Purchase of treasury stock, shares			(278)
Net loss	(6,189)				(6,189)
Other comprehensive loss—net of tax	(1,249)					(1,249)
BALANCE - value at Dec. 31, 2015	$ 252,173	$ 6	$ (1,433)	$ 283,247	$ (27,664)	$ (1,983)
BALANCE - shares at Dec. 31, 2015		60,709	(278)

Consolidated Statements Of Cash

Consolidated Statements Of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING ACTIVITIES:
Net income (loss)	$ (6,189)	$ 10,295	$ (34,993)
Loss from discontinued operations, net of income taxes		(10,423)	(54,850)
Income from continuing operations	(6,189)	20,718	19,857
Adjustments to reconcile net income to net cash flows used in operating activities:
Depreciation and amortization	64,585	50,129	46,622
Equity in (earnings) loss of joint ventures	771	(2,895)	(1,208)
Cash distributions from joint ventures	8,384	19,955
Deferred income taxes	(2,689)	(14,504)	(304)
(Gain) loss on dispositions of property and equipment	(855)	732	(5,773)
Impairment of goodwill	2,750
Gain on adjustment of contingent consideration	(8,444)	(1,086)
Amortization of deferred financing fees	2,766	1,453	1,153
Gain on bargain purchase acquisition		(2,197)
Unrealized foreign currency (gain) loss	(1,054)	593	(179)
Unrealized net loss from mark-to-market valuations of derivatives	1,359	3,029
Share-based compensation expense	4,040	2,694	3,251
Excess income tax benefit from share-based compensation	57	(206)	(154)
Changes in assets and liabilities:
Accounts receivable	(20,190)	11,012	36,260
Contract revenues in excess of billings	48	(5,677)	(17,142)
Inventories	(6,612)	120	(5,144)
Prepaid expenses and other current assets	(9,730)	1,780	(10,124)
Accounts payable and accrued expenses	306	(14,113)	22,622
Billings in excess of contract revenues	2,325	(2,624)	(2,900)
Other noncurrent assets and liabilities	(2,506)	(1,759)	(490)
Net cash flows provided by operating activities of continuing operations	29,122	67,154	86,347
Net cash flows used in operating activities of discontinued operations		(18,352)	(11,524)
Cash provided by operating activities	29,122	48,802	74,823
INVESTING ACTIVITIES:
Purchases of property and equipment	(74,455)	(91,910)	(66,654)
Proceeds from dispositions of property and equipment	1,322	68	6,953
Proceeds from (payments on) vendor performance obligations (Note 13)		(3,100)	13,600
Payments for acquisitions of businesses, net of cash acquired		(27,048)
Net cash flows used in investing activities of continuing operations	(73,133)	(121,990)	(46,101)
Net cash flows provided by (used in) investing activities of discontinued operations		5,275	(153)
Cash used in investing activities	(73,133)	(116,715)	(46,254)
FINANCING ACTIVITIES:
Proceeds from term loan facility	2,640	47,360
Repayments of term loan facility	(5,000)	(417)
Proceeds from issuance of 7 3/8% senior notes		24,880
Deferred financing fees	(111)	(2,532)
Repayment of long term note payable	(443)		(13,047)
Distributions paid to minority interests			(3)
Taxes paid on settlement of vested share awards	(267)	(497)	(308)
Purchase of noncontrolling interest		(205)	(3)
Proceeds from equipment debt	410
Repayments of equipment debt	(1,201)	(235)
Exercise of stock options and purchases from employee stock plans	1,365	1,568	668
Excess income tax benefit from share-based compensation	(57)	206	154
Purchase of treasury stock	(1,433)
Borrowings under revolving loans	179,500	236,500	227,000
Repayments of revolving loans	(159,500)	(271,500)	(192,000)
Cash provided by financing activities	15,903	35,128	22,464
Effect of foreign currency exchange rates on cash and cash equivalents	(97)	(164)	(135)
Net increase (decrease) in cash and cash equivalents	(28,205)	(32,949)	50,898
Cash and cash equivalents at beginning of period	42,389	75,338	24,440
Cash and cash equivalents at end of period	14,184	42,389	75,338
Supplemental Cash Flow Information
Cash paid for interest	25,391	18,901	20,083
Cash paid (refunded) for income taxes	586	(10,544)	1,793
Non-cash Investing and Financing Activities
Property and equipment purchased but not yet paid	7,380	10,316	$ 3,552
Property and equipment purchased on capital leases and equipment notes	2,190	3,665
Property & equipment purchased on notes payable	$ 15,569
Magnus [Member]
Non-cash Investing and Financing Activities
Purchase price of Magnus assets comprised of promissory notes and other liabilities		$ 16,210

Nature Of Business And Summary

Nature Of Business And Summary Of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Nature Of Business And Summary Of Significant Accounting Policies	1. NATURE OF BUSINESS AND SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES Organization —Great Lakes Dredge & Dock Corporation and its subsidiaries (the “Company” or “Great Lakes”) are in the business of marine construction, primarily dredging, and soil, water and sediment environmental and remediation services. The Company’s primary dredging customers are domestic and foreign government agencies, as well as private entities, and its environmental and remediation customers are general contractors, corporations, environmental engineering and construction firms that commission projects and local government and municipal agencies. Principles of Consolidation and Basis of Presentation —The consolidated financial statements include the accounts of Great Lakes Dredge & Dock Corporation and its majority-owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation. The equity method of accounting is used for investments in unconsolidated investees in which the Company has significant influence, but not control. Other investments, if any, are carried at cost. Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect certain reported amounts and disclosures. Accordingly, actual results could differ from those estimates. Revenue and Cost Recognition on Contracts —Substantially all of the Company’s contracts for dredging services are fixed-price contracts, which provide for remeasurement based on actual quantities dredged. The majority of the Company’s environmental & remediation contracts are also fixed-price contracts, with others performed on a time-and-materials basis. Contract revenues are recognized under the percentage-of-completion method based on the Company’s engineering estimates of the physical percentage completed for dredging projects and based on costs incurred to date compared to total estimated costs for fixed-price environmental & remediation projects. For dredging projects, costs of contract revenues are adjusted to reflect the gross profit percentage expected to be achieved upon ultimate completion. For environmental & remediation contracts, contract revenues are adjusted to reflect the estimated gross profit percentage. Revisions in estimated gross profit percentages are recorded in the period during which the change in circumstances is experienced or becomes known. As the duration of most of the Company’s contracts is one year or less, the cumulative net impact of these revisions in estimates, individually and in the aggregate across our projects, does not significantly affect our results across annual reporting periods. Provisions for estimated losses on contracts in progress are made in the period in which such losses are determined. Change orders are not recognized in revenue until the recovery is probable and collectability is reasonably assured. Claims for additional compensation due to the Company are not recognized in contract revenues until such claims are settled. Billings on contracts are generally submitted after verification with the customers of physical progress and may not match the timing of revenue recognition. The difference between amounts billed and recognized as revenue is reflected in the balance sheet as either contract revenues in excess of billings or billings in excess of contract revenues. Modifications may be negotiated when a change from the original contract specification is encountered, and a change in project scope, performance methodology and/or material disposal is necessary. Thus, the resulting modification is considered a change in the scope of the original project to which it relates. Significant expenditures incurred incidental to major contracts are deferred and recognized as contract costs based on contract performance over the duration of the related project. These expenditures are reported as prepaid expenses. The components of costs of contract revenues include labor, equipment (including depreciation, maintenance, insurance and long-term rentals), subcontracts, fuel, supplies, short-term rentals and project overhead. Hourly labor generally is hired on a project-by-project basis. Much of our domestic dredging hourly labor force is represented by labor unions with collective bargaining agreements that expire at various dates during 2016 through 2018, which historically have been extended without disruption. The environmental & remediation segment’s hourly labor force is made up of union and non-union employees. Project costs, excluding labor, have averaged approximately 20% to 22% of total costs of contract revenues over the prior three years. During the year, both dredging equipment utilization and the timing of fixed cost expenditures fluctuate significantly. Accordingly, the Company allocates these fixed equipment costs to interim periods in proportion to dredging revenues recognized over the year, to better match revenues and expenses. Specifically, at each interim reporting date the Company compares actual dredging revenues earned to date on the Company’s dredging contracts to expected annual revenues and recognizes dredging equipment costs on the same proportionate basis. In the fourth quarter, any over or under allocated equipment costs are recognized such that the expense for the year equals actual equipment costs incurred during the year. As a result of this methodology, the recorded expense in any interim period may be higher or lower than the actual equipment costs incurred in that interim period. For some environmental & remediation contracts, the Company has entered into unincorporated construction joint ventures under which certain portions of a larger project are performed. These investments are accounted for under the proportionate consolidation method for income statement reporting and under the equity method for balance sheet reporting. The Company’s interests in any profits and assets and proportionate share in any losses and liabilities are recognized based on the Company’s stated percentage partnership interest in the project. For projects related to proportionately consolidated joint ventures, we include only the Company’s percentage ownership of each joint venture's backlog. Classification of Current Assets and Liabilities —The Company includes in current assets and liabilities amounts realizable and payable in the normal course of contract completion, unless completion of such contracts extends significantly beyond one year. Cash Equivalents —The Company considers all highly liquid investments with a maturity at purchase of three months or less to be cash equivalents. Accounts Receivable —Accounts receivable represent amounts due or billable under the terms of contracts with customers, including amounts related to retainage. The Company anticipates collection of retainage generally within one year, and accordingly presents retainage as a current asset. The Company provides an allowance for estimated uncollectible accounts receivable when events or conditions indicate that amounts outstanding are not recoverable. Inventories —Inventories consist of pipe and spare parts used in the Company’s dredging operations. Pipe and spare parts are purchased in large quantities; therefore, a certain amount of pipe and spare part inventories is not anticipated to be used within the current year and is classified as long-term. Spare part inventories are stated at weighted average historical cost, and are charged to expense when used in operations. Pipe inventory is recorded at cost and amortized to expense over the period of its use. Property and Equipment —Capital additions, improvements, and major renewals are classified as property and equipment and are carried at depreciated cost. Maintenance and repairs that do not significantly extend the useful lives of the assets or enhance the capabilities of such assets are charged to expenses as incurred. Depreciation is recorded over the estimated useful lives of property and equipment using the straight-line method and the mid-year depreciation convention. The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30 Leasehold improvements are amortized over the shorter of their remaining useful lives or the remaining terms of the leases. Goodwill and Other Intangible Assets —Goodwill represents the excess of acquisition cost over fair value of the net assets acquired. Other identifiable intangible assets mainly represent developed technology and databases, customer relationships, and customer contracts acquired in business combinations and are being amortized over a one to five-year period. Goodwill is tested annually for impairment in the third quarter of each year, or more frequently should circumstances dictate. GAAP requires that goodwill of a reporting unit be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company assesses the fair values of its reporting units using both a market-based approach and an income-based approach. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows. The income approach is dependent on a number of factors, including estimates of future market growth trends, forecasted revenues and expenses, appropriate discount rates and other variables. The estimates are based on assumptions that the Company believes to be reasonable, but such assumptions are subject to unpredictability and uncertainty. Changes in these estimates and assumptions could materially affect the determination of fair value, and may result in the impairment of goodwill in the event that actual results differ from those estimates. The market approach measures the value of a reporting unit through comparison to comparable companies. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA. The Company analyzes companies that performed similar services or are considered peers. Due to the fact that there are no public companies that are direct competitors, the Company weighs the results of this approach less than the income approach. The Company has three operating segments: dredging, Terra and Magnus, which were aggregated into two reportable segments: dredging and environmental & remediation. As Terra and Magnus have similarity in economic margins, services, production processes, customer types, distribution methods and regulatory environment, they were aggregated into one reporting segment. The historical demolition business has been retrospectively presented as discontinued operations and is no longer reflected in continuing operations. The Company has determined that the operating segments are the Company’s three reporting units. Long-Lived Assets —Long-lived assets are comprised of property and equipment and intangible assets subject to amortization. Long-lived assets to be held and used are reviewed for possible impairment whenever events indicate that the carrying amount of such assets may not be recoverable by comparing the undiscounted cash flows associated with the assets to their carrying amounts. If such a review indicates an impairment, the carrying amount would be reduced to fair value. No triggering events were identified in 2015 or 2014. If long-lived assets are to be disposed, depreciation is discontinued, if applicable, and the assets are reclassified as held for sale at the lower of their carrying amounts or fair values less estimated costs to sell. The Company capitalizes construction in progress and records a corresponding long-term liability for build-to-suit lease agreements where we are considered the owner during the construction period for accounting purposes. There was no build-to-suit equipment capitalized at December 31, 2015. Self-insurance Reserves —The Company self-insures costs associated with its seagoing employees covered by the provisions of Jones Act, workers’ compensation claims, hull and equipment liability, and general business liabilities up to certain limits. Insurance reserves are established for estimates of the loss that the Company may ultimately incur on reported claims, as well as estimates of claims that have been incurred but not yet reported. In determining its estimates, the Company considers historical loss experience and judgments about the present and expected levels of cost per claim. Trends in actual experience are a significant factor in the determination of such reserves. Income Taxes —The provision for income taxes includes federal, foreign, and state income taxes currently payable and those deferred because of temporary differences between the financial statement and tax basis of assets and liabilities. Recorded deferred income tax assets and liabilities are based on the estimated future tax effects of differences between the financial and tax basis of assets and liabilities, given the effect of currently enacted tax laws. The Company’s current policy is to repatriate all earnings from foreign subsidiaries’ operations as generated and at this time no amounts are considered to be permanently reinvested in those operations. Hedging Instruments —At times, the Company designates certain derivative contracts as a cash flow hedge as defined by GAAP. Accordingly, the Company formally documents, at the inception of each hedge, all relationships between hedging instruments and hedged items, as well as our risk-management objective and strategy for undertaking hedge transactions. This process includes linking all derivatives to highly-probable forecasted transactions. The Company formally assesses, at inception and on an ongoing basis, the effectiveness of hedges in offsetting changes in the cash flows of hedged items. Hedge accounting treatment may be discontinued when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the cash flows of a hedged item (including hedged items for forecasted future transactions), (2) the derivative expires or is sold, terminated or exercised, (3) it is no longer probable that the forecasted transaction will occur or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate. If management elects to stop hedge accounting, it would be on a prospective basis and any hedges in place would be recognized in accumulated other comprehensive income (loss) until all the related forecasted transactions are completed or are probable of not occurring. Foreign Currency Translation —The financial statements of the Company’s foreign subsidiaries where the operations are primarily denominated in the foreign currency are translated into U.S. dollars for reporting. Balance sheet accounts are translated at the current foreign exchange rate at the end of each period and income statement accounts are translated at the average foreign exchange rate for each period. Gains and losses on foreign currency translations are reflected as a currency translation adjustment, net of tax, in accumulated other comprehensive income (loss). Foreign currency transaction gains and losses are included in other income (expense). Noncontrolling Interest —On January 1, 2009 the Company acquired a 65% interest in Yankee Environmental Services, LLC (“Yankee”). On April 23, 2014, the Company entered into and completed the sale of NASDI, LLC and Yankee, its two former subsidiaries that comprised the historical demolition business. As a result of the sale, the Company purchased the noncontrolling interest related to the membership interest the Company did not own in Yankee. Noncontrolling interest at December 31, 2013 is related to the membership interest the Company did not own in Yankee. Recent Accounting Pronouncements — In November 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update No. 2015-17 (“ASU 2015-17”), Income Taxes: Balance Sheet Classifications of Deferred Taxes (Topic 740) which simplifies the presentation of deferred income taxes by requiring that deferred tax liabilities and assets be classified as noncurrent in the balance sheet. The update is effective for public companies for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. The guidance may be adopted prospectively or retrospectively and early adoption is permitted. As of December 31, 2015, the Company has elected to early adopt this ASU 2015-17 on a prospective basis and therefore, prior years were not retrospectively adjusted. See Note 10 for additional information. In April 2015, the FASB issued Accounting Standard Update No. 2015-03 (“ASU 2015-03”), Interest - Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs In May 2014, the FASB issued Accounting Standard Update No. 2014-09 (“ASU 2014-09”), Revenue from Contracts with Customers (Topic 606)

Nature Of Business And Summar10

Nature Of Business And Summary Of Significant Accounting Policies (Policy)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Principles Of Consolidation And Basis Of Presentation	Principles of Consolidation and Basis of Presentation —The consolidated financial statements include the accounts of Great Lakes Dredge & Dock Corporation and its majority-owned subsidiaries. All intercompany accounts and transactions are eliminated in consolidation. The equity method of accounting is used for investments in unconsolidated investees in which the Company has significant influence, but not control. Other investments, if any, are carried at cost.
Use Of Estimates	Use of Estimates —The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America (“GAAP”) requires management to make estimates and assumptions that affect certain reported amounts and disclosures. Accordingly, actual results could differ from those estimates.
Revenue and Cost Recognition on Contracts	Revenue and Cost Recognition on Contracts —Substantially all of the Company’s contracts for dredging services are fixed-price contracts, which provide for remeasurement based on actual quantities dredged. The majority of the Company’s environmental & remediation contracts are also fixed-price contracts, with others performed on a time-and-materials basis. Contract revenues are recognized under the percentage-of-completion method based on the Company’s engineering estimates of the physical percentage completed for dredging projects and based on costs incurred to date compared to total estimated costs for fixed-price environmental & remediation projects. For dredging projects, costs of contract revenues are adjusted to reflect the gross profit percentage expected to be achieved upon ultimate completion. For environmental & remediation contracts, contract revenues are adjusted to reflect the estimated gross profit percentage. Revisions in estimated gross profit percentages are recorded in the period during which the change in circumstances is experienced or becomes known. As the duration of most of the Company’s contracts is one year or less, the cumulative net impact of these revisions in estimates, individually and in the aggregate across our projects, does not significantly affect our results across annual reporting periods. Provisions for estimated losses on contracts in progress are made in the period in which such losses are determined. Change orders are not recognized in revenue until the recovery is probable and collectability is reasonably assured. Claims for additional compensation due to the Company are not recognized in contract revenues until such claims are settled. Billings on contracts are generally submitted after verification with the customers of physical progress and may not match the timing of revenue recognition. The difference between amounts billed and recognized as revenue is reflected in the balance sheet as either contract revenues in excess of billings or billings in excess of contract revenues. Modifications may be negotiated when a change from the original contract specification is encountered, and a change in project scope, performance methodology and/or material disposal is necessary. Thus, the resulting modification is considered a change in the scope of the original project to which it relates. Significant expenditures incurred incidental to major contracts are deferred and recognized as contract costs based on contract performance over the duration of the related project. These expenditures are reported as prepaid expenses. The components of costs of contract revenues include labor, equipment (including depreciation, maintenance, insurance and long-term rentals), subcontracts, fuel, supplies, short-term rentals and project overhead. Hourly labor generally is hired on a project-by-project basis. Much of our domestic dredging hourly labor force is represented by labor unions with collective bargaining agreements that expire at various dates during 2016 through 2018, which historically have been extended without disruption. The environmental & remediation segment’s hourly labor force is made up of union and non-union employees. Project costs, excluding labor, have averaged approximately 20% to 22% of total costs of contract revenues over the prior three years. During the year, both dredging equipment utilization and the timing of fixed cost expenditures fluctuate significantly. Accordingly, the Company allocates these fixed equipment costs to interim periods in proportion to dredging revenues recognized over the year, to better match revenues and expenses. Specifically, at each interim reporting date the Company compares actual dredging revenues earned to date on the Company’s dredging contracts to expected annual revenues and recognizes dredging equipment costs on the same proportionate basis. In the fourth quarter, any over or under allocated equipment costs are recognized such that the expense for the year equals actual equipment costs incurred during the year. As a result of this methodology, the recorded expense in any interim period may be higher or lower than the actual equipment costs incurred in that interim period. For some environmental & remediation contracts, the Company has entered into unincorporated construction joint ventures under which certain portions of a larger project are performed. These investments are accounted for under the proportionate consolidation method for income statement reporting and under the equity method for balance sheet reporting. The Company’s interests in any profits and assets and proportionate share in any losses and liabilities are recognized based on the Company’s stated percentage partnership interest in the project. For projects related to proportionately consolidated joint ventures, we include only the Company’s percentage ownership of each joint venture's backlog.
Classification of Current Assets and Liabilities	Classification of Current Assets and Liabilities —The Company includes in current assets and liabilities amounts realizable and payable in the normal course of contract completion, unless completion of such contracts extends significantly beyond one year.
Cash Equivalents	Cash Equivalents —The Company considers all highly liquid investments with a maturity at purchase of three months or less to be cash equivalents.
Accounts Receivable	Accounts Receivable —Accounts receivable represent amounts due or billable under the terms of contracts with customers, including amounts related to retainage. The Company anticipates collection of retainage generally within one year, and accordingly presents retainage as a current asset. The Company provides an allowance for estimated uncollectible accounts receivable when events or conditions indicate that amounts outstanding are not recoverable.
Inventories	Inventories —Inventories consist of pipe and spare parts used in the Company’s dredging operations. Pipe and spare parts are purchased in large quantities; therefore, a certain amount of pipe and spare part inventories is not anticipated to be used within the current year and is classified as long-term. Spare part inventories are stated at weighted average historical cost, and are charged to expense when used in operations. Pipe inventory is recorded at cost and amortized to expense over the period of its use.
Property, Plant and Equipment	Property and Equipment —Capital additions, improvements, and major renewals are classified as property and equipment and are carried at depreciated cost. Maintenance and repairs that do not significantly extend the useful lives of the assets or enhance the capabilities of such assets are charged to expenses as incurred. Depreciation is recorded over the estimated useful lives of property and equipment using the straight-line method and the mid-year depreciation convention. The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30 Leasehold improvements are amortized over the shorter of their remaining useful lives or the remaining terms of the leases.
Goodwill and Other Intangible Assets	Goodwill and Other Intangible Assets —Goodwill represents the excess of acquisition cost over fair value of the net assets acquired. Other identifiable intangible assets mainly represent developed technology and databases, customer relationships, and customer contracts acquired in business combinations and are being amortized over a one to five-year period. Goodwill is tested annually for impairment in the third quarter of each year, or more frequently should circumstances dictate. GAAP requires that goodwill of a reporting unit be tested for impairment between annual tests if an event occurs or circumstances change that would more likely than not reduce the fair value of a reporting unit below its carrying amount. The Company assesses the fair values of its reporting units using both a market-based approach and an income-based approach. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows. The income approach is dependent on a number of factors, including estimates of future market growth trends, forecasted revenues and expenses, appropriate discount rates and other variables. The estimates are based on assumptions that the Company believes to be reasonable, but such assumptions are subject to unpredictability and uncertainty. Changes in these estimates and assumptions could materially affect the determination of fair value, and may result in the impairment of goodwill in the event that actual results differ from those estimates. The market approach measures the value of a reporting unit through comparison to comparable companies. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA. The Company analyzes companies that performed similar services or are considered peers. Due to the fact that there are no public companies that are direct competitors, the Company weighs the results of this approach less than the income approach. The Company has three operating segments: dredging, Terra and Magnus, which were aggregated into two reportable segments: dredging and environmental & remediation. As Terra and Magnus have similarity in economic margins, services, production processes, customer types, distribution methods and regulatory environment, they were aggregated into one reporting segment. The historical demolition business has been retrospectively presented as discontinued operations and is no longer reflected in continuing operations. The Company has determined that the operating segments are the Company’s three reporting units.
Long-Lived Assets	Long-Lived Assets —Long-lived assets are comprised of property and equipment and intangible assets subject to amortization. Long-lived assets to be held and used are reviewed for possible impairment whenever events indicate that the carrying amount of such assets may not be recoverable by comparing the undiscounted cash flows associated with the assets to their carrying amounts. If such a review indicates an impairment, the carrying amount would be reduced to fair value. No triggering events were identified in 2015 or 2014. If long-lived assets are to be disposed, depreciation is discontinued, if applicable, and the assets are reclassified as held for sale at the lower of their carrying amounts or fair values less estimated costs to sell. The Company capitalizes construction in progress and records a corresponding long-term liability for build-to-suit lease agreements where we are considered the owner during the construction period for accounting purposes. There was no build-to-suit equipment capitalized at December 31, 2015.
Self-insurance Reserves	Self-insurance Reserves —The Company self-insures costs associated with its seagoing employees covered by the provisions of Jones Act, workers’ compensation claims, hull and equipment liability, and general business liabilities up to certain limits. Insurance reserves are established for estimates of the loss that the Company may ultimately incur on reported claims, as well as estimates of claims that have been incurred but not yet reported. In determining its estimates, the Company considers historical loss experience and judgments about the present and expected levels of cost per claim. Trends in actual experience are a significant factor in the determination of such reserves.
Income Taxes	Income Taxes —The provision for income taxes includes federal, foreign, and state income taxes currently payable and those deferred because of temporary differences between the financial statement and tax basis of assets and liabilities. Recorded deferred income tax assets and liabilities are based on the estimated future tax effects of differences between the financial and tax basis of assets and liabilities, given the effect of currently enacted tax laws. The Company’s current policy is to repatriate all earnings from foreign subsidiaries’ operations as generated and at this time no amounts are considered to be permanently reinvested in those operations.
Hedging Instruments	Hedging Instruments —At times, the Company designates certain derivative contracts as a cash flow hedge as defined by GAAP. Accordingly, the Company formally documents, at the inception of each hedge, all relationships between hedging instruments and hedged items, as well as our risk-management objective and strategy for undertaking hedge transactions. This process includes linking all derivatives to highly-probable forecasted transactions. The Company formally assesses, at inception and on an ongoing basis, the effectiveness of hedges in offsetting changes in the cash flows of hedged items. Hedge accounting treatment may be discontinued when (1) it is determined that the derivative is no longer highly effective in offsetting changes in the cash flows of a hedged item (including hedged items for forecasted future transactions), (2) the derivative expires or is sold, terminated or exercised, (3) it is no longer probable that the forecasted transaction will occur or (4) management determines that designating the derivative as a hedging instrument is no longer appropriate. If management elects to stop hedge accounting, it would be on a prospective basis and any hedges in place would be recognized in accumulated other comprehensive income (loss) until all the related forecasted transactions are completed or are probable of not occurring.
Foreign Currency Translation	Foreign Currency Translation —The financial statements of the Company’s foreign subsidiaries where the operations are primarily denominated in the foreign currency are translated into U.S. dollars for reporting. Balance sheet accounts are translated at the current foreign exchange rate at the end of each period and income statement accounts are translated at the average foreign exchange rate for each period. Gains and losses on foreign currency translations are reflected as a currency translation adjustment, net of tax, in accumulated other comprehensive income (loss). Foreign currency transaction gains and losses are included in other income (expense).
Noncontrolling Interest	Noncontrolling Interest — On January 1, 2009 the Company acquired a 65% interest in Yankee Environmental Services, LLC (“Yankee”). On April 23, 2014, the Company entered into and completed the sale of NASDI, LLC and Yankee, its two former subsidiaries that comprised the historical demolition business. As a result of the sale, the Company purchased the noncontrolling interest related to the membership interest the Company did not own in Yankee. Noncontrolling interest at December 31, 2013 is related to the membership interest the Company did not own in Yankee.
Recent Accounting Pronouncements	Recent Accounting Pronouncements — In November 2015, the Financial Accounting Standards Board (“FASB”) issued Accounting Standard Update No. 2015-17 (“ASU 2015-17”), Income Taxes: Balance Sheet Classifications of Deferred Taxes (Topic 740) which simplifies the presentation of deferred income taxes by requiring that deferred tax liabilities and assets be classified as noncurrent in the balance sheet. The update is effective for public companies for fiscal years beginning after December 15, 2016, including interim periods within that reporting period. The guidance may be adopted prospectively or retrospectively and early adoption is permitted. As of December 31, 2015, the Company has elected to early adopt this ASU 2015-17 on a prospective basis and therefore, prior years were not retrospectively adjusted. See Note 10 for additional information. In April 2015, the FASB issued Accounting Standard Update No. 2015-03 (“ASU 2015-03”), Interest - Imputation of Interest: Simplifying the Presentation of Debt Issuance Costs In May 2014, the FASB issued Accounting Standard Update No. 2014-09 (“ASU 2014-09”), Revenue from Contracts with Customers (Topic 606)

Earnings per share

Earnings per share	12 Months Ended
	Dec. 31, 2015
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. For the year ended December 31, 2015, the dilutive effect of 431 thousand 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 this period. For the year ended December 31, 2015 and 2014, 1,179 shares and 540 shares 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. The computations for basic and diluted earnings per share for the years ended December 31, 2015, 2014 and 2013 are as follows: (shares in thousands) 2015 2014 2013 Income (loss) from continuing operations $ (6,189 ) $ 20,718 $ 19,857 Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation — (10,423 ) (54,218 ) Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ (6,189 ) $ 10,295 $ (34,361 ) Weighted-average common shares outstanding — basic 60,410 59,938 59,495 Effect of stock options and restricted stock units — 584 606 Weighted-average common shares outstanding — diluted 60,410 60,522 60,101 Earnings (loss) per share from continuing operations — basic $ (0.10 ) $ 0.35 $ 0.33 Earnings (loss) per share from continuing operations — diluted $ (0.10 ) $ 0.34 $ 0.33

Restricted And Escrowed Cash

Restricted And Escrowed Cash	12 Months Ended
	Dec. 31, 2015
Cash And Cash Equivalents [Abstract]
Restricted And Escrowed Cash	3. RESTRICTED AND ESCROWED CASH At December 31, 2015 and 2014, other noncurrent assets include $1,500 of cash held in escrow as security for the Company’s lease rental obligation under a long-term equipment operating lease. At December 31, 2015 and 2014, other current assets include $2,242 and $2,314, respectively, of cash held in escrow related to an outstanding lawsuit at our historical demolition business.

Accounts Receivable And Contrac

Accounts Receivable And Contracts In Progress	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Accounts Receivables And Contracts In Progress	4. ACCOUNTS RECEIVABLE AND CONTRACTS IN PROGRESS Accounts receivable at December 31, 2015 and 2014 are as follows: 2015 2014 Completed contracts $ 37,111 $ 15,342 Contracts in progress 70,787 72,459 Retainage 27,203 27,371 135,101 115,172 Allowance for doubtful accounts (754 ) (578 ) Total accounts receivable—net $ 134,347 $ 114,594 Current portion of accounts receivable—net $ 130,777 $ 113,188 Long-term accounts receivable and retainage 3,570 1,406 Total accounts receivable—net $ 134,347 $ 114,594 The components of contracts in progress at December 31, 2015 and 2014 are as follows: 2015 2014 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 230,159 $ 833,368 Amounts billed (176,283 ) (759,877 ) Costs and earnings in excess of billings for contracts in progress 53,876 73,491 Costs and earnings in excess of billings for completed contracts 27,319 9,066 Total contract revenues in excess of billings $ 81,195 $ 82,557 Billings in excess of costs and earnings: Amounts billed $ (207,550 ) $ (181,698 ) Costs and earnings for contracts in progress 200,489 177,059 Total billings in excess of contract revenues $ (7,061 ) $ (4,639 )

Property And Equipment

Property And Equipment	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Property And Equipment	5. PROPERTY AND EQUIPMENT Property and equipment at December 31, 2015 and 2014 are as follows: 2015 2014 Land $ 9,864 $ 9,220 Buildings and improvements 5,896 5,729 Furniture and fixtures 10,587 8,863 Operating equipment 783,732 698,977 Total property and equipment 810,079 722,789 Accumulated depreciation (379,869 ) (323,344 ) Property and equipment — net $ 430,210 $ 399,445 Depreciation expense was $58,050, $48,569 and $45,531, for the years ended December 31, 2015, 2014 and 2013, respectively.

Goodwill And Other Intangible A

Goodwill And Other Intangible Assets	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Goodwill And Other Intangible Assets	6. The Company’s annual goodwill impairment test is conducted in the third quarter of each year and interim evaluations are performed when the Company determines that a triggering event has occurred that would more likely than not reduce the fair value of goodwill below its carrying value. Due to a decline in the overall financial performance and declining cash flows in the Terra reporting unit, the Company concluded there was a triggering event that required an interim impairment test for the reporting unit in the second quarter of 2015. The Company performed step one of the goodwill impairment test as of June 30, 2015, which compared the fair value of the Terra reporting unit against its carrying amount, including goodwill. In deriving the fair value of the Terra reporting unit, the Company used both a market-based approach and an income-based approach. Under the income approach, the fair value of the reporting unit is based on the present value of estimated future cash flows. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA from continuing operations. Based on the first step analysis, management concluded that the fair value of the Terra reporting unit was less than its carrying value; therefore, the Company performed step two of the goodwill impairment analysis. Step two of the goodwill impairment analysis measures the impairment charge by allocating the reporting unit’s fair value to all of the assets and liabilities of the reporting unit in a hypothetical analysis that calculates implied fair value of goodwill in the same manner as if the reporting unit was being acquired in a business combination. Any excess of the carrying value of the reporting unit’s goodwill over the implied fair value of the reporting unit’s goodwill is recorded as a loss on impairment of goodwill. Management determined that the Terra reporting unit’s implied fair value of goodwill was below the carrying value as of June 30, 2015. As a result, the Company recorded an impairment charge of $2,750 in the second quarter of 2015. The Company performed its annual goodwill impairment test for the remaining reporting units in the third quarter and no additional impairment was recorded for the year ended December 31, 2015. As of the test date, the fair value of the remaining reporting units was substantially in excess of their carrying values. The Company will perform its next scheduled annual test of goodwill in the third quarter of 2016 should no triggering events occur which would require a test prior to the next annual test. The change in the carrying amount of goodwill during the years ended December 31, 2015 and 2014 is as follows: Dredgin g Environmental & Remediatio n Total Balance – January 1, 2014 $ 76,576 $ 2,750 $ 79,326 Acquisition of Magnus Pacific — 7,000 7,000 Balance – December 31, 2014 76,576 9,750 86,326 Impairment of goodwill — (2,750 ) (2,750 ) Balance – December 31, 2015 $ 76,576 $ 7,000 $ 83,576 At December 31, 2015 and 2014, the net book value of identifiable intangible assets was as follows: As of December 31, 2015 Cost Accumulated Amortization Net Non-compete agreements $ 3,085 $ 1,625 $ 1,460 Trade names 1,037 873 164 Other 1,306 502 804 $ 5,428 $ 3,000 $ 2,428 As of December 31, 2014 Non-compete agreements $ 3,085 $ 940 $ 2,145 Customer relationships 51 34 17 Acquired backlog 6,278 1,395 4,883 Trade names 1,037 185 852 Other 1,306 240 1,066 $ 11,757 $ 2,794 $ 8,963 On November 4, 2014, the Company acquired the assets of Magnus Pacific Corporation resulting in recognition of additional intangible assets and goodwill. The weighted average amortization period for intangible assets acquired in 2014 is 3.21 years. Amortization expense was $6,535, $1,560 and $1,091, for the years ended December 31, 2015, 2014 and 2013, respectively, and is included as a component of general and administrative expenses. Amortization expense related to intangible assets is estimated to be $920 in 2016, $920 in 2017, $454 in 2018 and $134 in 2019.

Accrued Expenses

Accrued Expenses	12 Months Ended
	Dec. 31, 2015
Payables And Accruals [Abstract]
Accrued Expenses	7. ACCRUED EXPENSES Accrued expenses at December 31, 2015 and 2014 are as follows: 2015 2014 Insurance $ 16,291 $ 16,778 Accumulated deficit in joint venture 15,408 10,383 Payroll and employee benefits 13,317 8,808 Interest 8,743 8,270 Fuel hedge contracts 4,388 3,029 Income and other taxes 3,726 5,857 Percentage of completion adjustment 2,837 1,870 Other 7,567 15,046 Total accrued expenses $ 72,277 $ 70,041

Long-Term Debt

Long-Term Debt	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Long-Term Debt	8. LONG-TERM DEBT Long-term debt at December 31, 2015 and 2014 is as follows: 2015 2014 Revolving credit facility $ 20,000 $ — Equipment notes payable 3,972 2,857 Notes payable 60,595 54,620 7.375% senior notes 274,909 274,880 Subtotal 359,476 332,357 Current portion of equipment note payable (1,293 ) (736 ) Current portion of note payable (6,213 ) (5,123 ) Capital leases (included in other long term liabilities) (2,679 ) (2,121 ) Total $ 349,291 $ 324,377 Credit agreement On June 4, 2012, the Company entered into a senior revolving credit agreement, as subsequently amended, (the “Credit Agreement”) with certain financial institutions from time to time party thereto as lenders, Wells Fargo Bank, National Association, as Administrative Agent, Swingline Lender and an Issuing Lender, Bank of America, N.A., as Syndication Agent and PNC Bank, National Association, BMO Harris Bank N.A. and Fifth Third Bank, as Co-Documentation Agents. The Credit Agreement provides for a senior revolving credit facility in an aggregate principal amount of up to $210,000, multicurrency borrowings up to a $50,000 sublimit and swingline loans up to a $10,000 sublimit. The Credit Agreement also includes an incremental loans feature that will allow the Company to increase the senior revolving credit facility by an aggregate principal amount of up to $15,000. This feature is subject to lenders providing incremental commitments for such increase, provided that no default or event of default exists, and the Company being in pro forma compliance with the existing financial covenants, both before and after giving effect to the increase, and subject to other standard conditions. The Credit Agreement is secured by a substantial portion of the Company’s operating equipment with a net book value at December 31, 2015 of $151,330. On September 15, 2014, the Company entered into the fifth amendment (the “Fifth Amendment”) to the Credit Agreement which exercised a portion of the incremental loans feature of the Credit Agreement that allowed the Company to increase the aggregate revolving commitment. The Fifth Amendment further amended the Credit Agreement so that the Credit Agreement will remain secured and collateralized by perfected liens on certain of the Company’s vessels and its domestic accounts receivable, subject to permitted liens and prior interests of other parties. In addition, Zurich American Insurance Company, the Company’s surety provider, secured permitted second mortgages on the same vessels securing the obligations under the Credit Agreement. On November 4, 2014, the Company entered into the sixth amendment (“Sixth Amendment”) to the Credit Agreement permitting the entrance into the Term Loan Facility (as defined below) and incurrence of liens securing the Term Loan Facility, subject to certain restrictions and conditions; permitting voluntary prepayments of the Term Loan Facility so long as, after giving effect to any such voluntary prepayment, the Company’s total leverage ratio is less than or equal to 3.00 to 1.00 and its fixed charge coverage ratio is greater than or equal to 1.25 to 1.00; permitting the acquisition of Magnus Pacific Corporation (See Note 16) without diminishing the amount currently available under the Credit Agreement for additional “Permitted Acquisitions” (as defined in the Credit Agreement); excluding the potential earnout obligation of the Company in connection with the acquisition of Magnus Pacific Corporation of up to $11.4 million from “Indebtedness” (as defined in the Credit Agreement) and the total leverage ratio under the Credit Agreement; and permitting the issuance of up to an additional $50 million in aggregate principal amount of the Company’s currently outstanding 7.375% senior notes due 2019. Depending on the Company’s consolidated leverage ratio (as defined in the Credit Agreement), borrowings under the amended revolving credit facility will bear interest at the option of the Company at either a LIBOR rate plus a margin of between 1.50% to 2.50% per annum or a base rate plus a margin of between 0.50% to 1.50% per annum. The Credit Agreement contains affirmative, negative and financial covenants customary for financings of this type. The 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 provider. The Credit Agreement requires the Company to maintain a net leverage ratio less than or equal to 4.50 to 1.00 as of the end of each fiscal quarter and a minimum fixed charge coverage ratio of 1.25 to 1.00. The obligations of Great Lakes under the Credit Agreement are 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. As of December 31, 2015, the Company had $20,000 of borrowings on the revolver and $81,943 of letters of credit outstanding, resulting in $108,057 of availability under the Credit Agreement. At December 31, 2015, the Company was in compliance with its various financial covenants under its Credit Agreement. Term loan facility On November 4, 2014, the Company entered into a new senior secured term loan facility consisting of a term loan in an aggregate principal amount of $50,000 (the “Term Loan Facility”) pursuant to a Loan and Security Agreement (the “Loan Agreement”) by and among, the lenders party thereto from time to time and Bank of America, N.A., as administrative agent. Pursuant to the term loan, the Company borrowed an aggregate principal amount of $47,360 in 2014 and an additional $2,640 in 2015. The proceeds from the Term Loan Facility will be used for the working capital and general corporate purposes of the Company, including to repay borrowings under the Credit Agreement made to finance the construction of the Company’s dual mode articulated tug/barge trailing suction hopper dredge (the “ATB”). The Term Loan Facility has a term of 5 years. The borrowings under the Term Loan Facility bear interest at a fixed rate of 4.655% per annum. If an event of default occurs under the Loan Agreement, the interest rate will increase by 2.00% per annum during the continuance of such event of default. The Term Loan Facility provides for monthly amortization payments, payable in arrears, commencing on December 4, 2014, at an annual amount of (i) approximately 10% of the principal amount of the Term Loan Facility during the first two years of the term, (ii) approximately 20% of the principal amount of the Term Loan Facility during the third and fourth years of the term, and (iii) approximately 25% of the principal amount of the Term Loan Facility during the final year of the term, with the remainder due on the maturity date of the facility. In addition, the Company has usual and customary mandatory prepayment provisions and may optionally prepay the Term Loan Facility in whole or in part at any time, subject to a minimum prepayment amount. The Loan Agreement includes customary representations, affirmative and negative covenants and events of default for financings of this type and includes the same financial covenants that are currently set forth in the Credit Agreement. The Term Loan Facility is secured by a portion of the Company’s operating equipment with a net book value at December 31, 2015 of $49,132. Senior notes The Company has outstanding $275,000 of 7.375% senior notes due February 2019. In January 2011, the Company issued $250,000 of senior notes and in November 2014 added $25,000 of senior notes. The total balance outstanding for all senior notes at December 31, 2015 was $274,909, based on the discounted issuance of the November 2014 notes. As of February 1, 2015, there is an optional redemption on all notes. The redemption prices are 103.7% in 2015, 101.8% in 2016 and 100% in any year following, until the notes mature in 2019. Interest is paid semi-annually and principal is due at maturity. Other In conjunction with the acquisition of Magnus Pacific Corporation (See Note 16), the Company issued a secured promissory note with a fair market value of $8,100 to the former owners of Magnus which had terms that could reduce the amount owed based on minimum EBITDA expectations. Based on the Company’s operating projections at June 30, 2015, Magnus was not expected to reach the minimum EBITDA threshold for 2015 designated in the promissory note; therefore, during the second quarter, the Company reduced the remaining fair value by $7,013 to zero. The corresponding change is reflected in general and administrative expenses. The Company enters into note arrangements to finance certain vessels and ancillary equipment. During the first quarter of 2015, the Company financed the $15,569 acquisition of a vessel previously under an operating lease with a note bearing interest at 5.75% to maturity in 2023. The scheduled principal payments through the maturity date of the Company’s long-term debt, excluding equipment notes and capital leases, at December 31, 2015, are as follows: Years Ending December 31 2016 $ 21,498 2017 16,145 2018 11,421 2019 295,461 2020 1,815 Thereafter 8,800 Total $ 355,140 The Company incurred amortization of deferred financing fees for its long term debt of $1,729, $1,453 and $1,153 for each of the years ended December 31, 2015, 2014 and 2013. Such amortization is recorded as a component of interest expense.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Fair Value Measurements	9. FAIR VALUE MEASUREMENTS Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. A fair value hierarchy has been established by GAAP that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The accounting guidance describes three levels of inputs that may be used to measure fair value: Level 1—Quoted prices in active markets for identical assets or liabilities. Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities. Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities. The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. At times, the Company holds certain derivative contracts that it uses to manage foreign currency risk or commodity price risk. The Company does not hold or issue derivatives for speculative or trading purposes. The fair values of these financial instruments are summarized as follows: Fair Value Measurements at Reporting Date Using Description At December 31, 2015 Quoted Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable (Level 3) Fuel hedge contracts $ 4,388 $ — $ 4,388 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 3,029 $ — $ 3,029 $ — Foreign exchange contracts The Company has various exposures to foreign currencies that fluctuate in relation to the U.S. dollar. The Company periodically enters into foreign exchange forward contracts to hedge this risk. At December 31, 2015 and 2014 there were no outstanding contracts. Fuel hedge contracts The Company is exposed to certain market risks, primarily commodity price risk as it relates to the diesel fuel purchase requirements, which occur in the normal course of business. The Company enters into heating oil commodity swap contracts to hedge the risk that fluctuations in diesel fuel prices will have an adverse impact on cash flows associated with its domestic dredging contracts. The Company’s goal is to hedge approximately 80% of the fuel requirements for work in domestic backlog. As of December 31, 2015, 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 November 2016. As of December 31, 2015, there were 9.2 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted domestic fuel purchases through November 2016. Under these swap agreements, the Company will pay fixed prices ranging from $1.32 to $2.11 per gallon. At December 31, 2015 and 2014, the fair value liability of the fuel hedge contracts was estimated to be $4,388 and $3,029, respectively, and is recorded in accrued expenses. Changes in the fair value of fuel hedge contracts being recorded in the Statement of Operations are recorded as cost of contract revenues. 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 December 31, 2015 and 2014 is as follows: Balance Sheet Location Fair Value at December 31, 2015 2014 Liability derivatives: Derivatives not designated as hedges Fuel hedge contracts Accrued expenses $ 4,388 $ 3,029 Assets and liabilities measured at fair value on a nonrecurring basis All other nonfinancial assets and liabilities measured at fair value in the financial statements on a nonrecurring basis are subject to fair value measurements and disclosures. Nonfinancial assets and liabilities included in our condensed consolidated balance sheets and measured on a nonrecurring basis consist of goodwill and long-lived assets, including other acquired intangibles. Goodwill and long-lived assets are measured at fair value to test for and measure impairment, if any, at least annually for goodwill or when necessary for both goodwill and long-lived assets. The Company estimated the fair value of our Terra reporting unit for our goodwill impairment test by using both a market-based approach and an income-based approach. The income approach is dependent on a number of factors, including estimates of future market growth trends, forecasted revenues and expenses based upon historical operating data, appropriate discount rates and other variables. The market approach measures the value of a reporting unit through comparison to comparable companies. Under the market approach, the Company uses the guideline public company method by applying estimated market-based enterprise value multiples to the reporting unit’s estimated revenue and Adjusted EBITDA from continuing operations. The Company analyzed companies that performed similar services or are considered peers. An impairment of goodwill was recorded in the amount of $2,750 in the second quarter of 2015. The fair value of goodwill was determined using quantitative models that contained significant unobservable inputs and accordingly is a Level 3 fair value measurement. See Note 6. Fair 2015 Goodwill Balance at January 1, $ 86,326 Impairment of goodwill (2,750 ) Balance at December 31, 2015 $ 83,576 Accumulated other comprehensive loss Changes in the components of the accumulated balances of other comprehensive income are as follows: 2015 2014 2013 Cumulative translation adjustments—net of tax $ (1,249 ) $ (62 ) $ (397 ) Derivatives: Reclassification of derivative losses (gains) to earnings—net of tax — (332 ) 270 Change in fair value of derivatives—net of tax — 133 34 Net unrealized (gain) loss on derivatives—net of tax — (199 ) 304 Total other comprehensive loss $ (1,249 ) $ (261 ) $ (93 ) Adjustments reclassified from accumulated balances of other comprehensive income to earnings are as follows: Statement of Operations Location 2014 2013 Derivatives: Fuel hedge contracts Costs of contract revenues $ (286 ) $ 450 Income tax benefit 46 180 $ (332 ) $ 270 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 senior revolving credit agreement approximates fair value. The Company entered into a senior secured term loan facility in November 2014 that approximates fair value based upon comparable interest rates in the asset-backed financing market and the Company’s current credit rating. In January 2011 and again in November 2014, the Company issued a total of $275,000 of 7.375% senior notes due February 1, 2019, which were outstanding at December 31, 2015 (See Note 8). The senior notes are senior unsecured obligations of the Company and its subsidiaries that guarantee the senior notes. The fair value of the senior notes was $255,750 at December 31, 2015, which is a Level 1 fair value measurement as the senior notes value was obtained using quoted prices in active markets. It is impracticable to determine the fair value of outstanding letters of credit or performance, bid and payment bonds due to uncertainties as to the amount and timing of future obligations, if any.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Income Taxes	10. The Company’s income tax (provision) benefit from continuing and discontinued operations for the years ended December 31, 2015, 2014 and 2013 is as follows: 2015 2014 2013 Income tax (provision) benefit from continuing operations $ 2,497 $ 11,530 $ (10,460 ) Income tax benefit from discontinued operations — 8,744 19,116 Income tax benefit $ 2,497 $ 20,274 $ 8,656 The Company’s pre- tax income (loss) from domestic and foreign continuing operations for the years ended December 31, 2015, 2014 and 2013 is as follows: 2015 2014 2013 Domestic operations $ (35,996 ) $ (20,823 ) $ 23,716 Foreign operations 27,310 30,011 6,601 Total pre-tax income (loss) $ (8,686 ) $ 9,188 $ 30,317 The provision (benefit) for income taxes from continuing operations as of December 31, 2015, 2014 and 2013 is as follows: 2015 2014 2013 Federal: Current $ — $ (174 ) $ 8,384 Deferred (2,355 ) (9,531 ) 2,107 State: Current 115 277 439 Deferred (673 ) (3,577 ) (326 ) Foreign: Current 416 1,475 1,831 Deferred — — (1,975 ) Total $ (2,497 ) $ (11,530 ) $ 10,460 The Company’s income tax provision (benefit) from continuing operations reconciles to the provision at the statutory U.S. federal income tax rate of 35% for the years ended December 31, 2015, 2014 and 2013 as follows: 2015 2014 2013 Tax provision at statutory U.S. federal income tax rate $ (3,040 ) $ 3,214 $ 10,611 State income tax — net of federal income tax benefit (676 ) (2,726 ) 500 Worthless stock deduction — (9,631 ) — Charitable contributions (469 ) (1,764 ) — Adjustment to deferred tax depreciation 1,135 (1,670 ) — Change in deferred state tax rate — (811 ) — Research and development tax credits (286 ) (691 ) — Purchase price adjustment 393 (393 ) — Foreign income tax provision (benefit) — — 238 Changes in unrecognized tax benefits (186 ) 127 (196 ) Changes in valuation allowance 270 2,246 (500 ) Other 362 569 (193 ) Income tax provision (benefit) $ (2,497 ) $ (11,530 ) $ 10,460 During the fourth quarter of 2014, the Company liquidated one of its domestic subsidiaries which allowed it to claim a worthless stock deduction on its federal income tax return. The Company recorded an income tax benefit of $9,631 related to the worthless stock deduction. The Company utilized part of the benefit to offset income in the year and carried forward the remainder as a net operating loss to potentially offset future income. Accordingly, this benefit is characterized as a component of our continuing operations. In 2014, an entity 50% owned by the Company sold property to a third party and as part of the transaction donated adjacent property to a municipality. The fair market value of the donated property in excess of cost resulted in a benefit of $1,764 to the Company in 2014. In 2015, additional property was donated to the same municipality and the fair market value of the donated property in excess of the cost resulted in a benefit of $469 to the Company. At December 31, 2015 and 2014, the Company had loss carryforwards for federal income tax purposes of $70,534 and $55,328 respectively, which expire between 2034 and 2036. At December 31, 2015 and 2014, the Company had gross net operating loss carryforwards for state income tax purposes totaling $128,460 and $105,458, respectively, which expire between 2023 and 2035. The Company also has foreign gross net operating loss carryforwards of approximately $11,507 and $13,039 as of December 31, 2015 and 2014, which expire between 2016 and 2035. At December 31, 2015 and 2014, a full valuation allowance has been established for the deferred tax asset of $3,586 and $4,334 related to foreign net operating loss carryforwards, respectively, as the Company believes it is more likely than not that the net operating loss carryforwards will not be realized. As of December 31, 2015 and 2014, the Company had $157 and $442, respectively, in unrecognized tax benefits, the recognition of which would have an impact of $102 and $287 on the effective tax rate. The Company does not expect that total unrecognized tax benefits will significantly increase or decrease within the next 12 months. Below is a tabular reconciliation of the total amounts of unrecognized tax benefits at the beginning and end of each period. 2015 2014 2013 Unrecognized tax benefits — January 1 $ 442 $ 253 $ 471 Gross increases — tax positions in prior period — — — Gross increases — current period tax positions — 270 42 Gross decreases — expirations — (65 ) (201 ) Gross decreases — tax positions in prior period (285 ) (16 ) (59 ) Unrecognized tax benefits — December 31, $ 157 $ 442 $ 253 The Company’s policy is to recognize interest and penalties related to income tax matters in income tax expense. As of December 31, 2015 and 2014, the Company had approximately $23 and $24, respectively, of interest and penalties recorded. The Company files income tax returns at the U.S. federal level and in various state and foreign jurisdictions. U.S. federal income tax years prior to 2011 are closed and no longer subject to examination. The Company’s 2011 and 2012 U.S. federal income tax returns are currently under examination by the Internal Revenue Service. With few exceptions, the statute of limitations in state taxing jurisdictions in which the Company operates has expired for all years prior to 2011. In foreign jurisdictions in which the Company operates, years prior to 2010 are closed and are no longer subject to examination. The Company’s deferred tax assets (liabilities) at December 31, 2015 and 2014 are as follows: 2015 2014 Deferred tax assets: Accrued liabilities $ 17,841 $ 13,288 Federal NOLs 24,687 19,365 Foreign NOLs 3,586 4,334 State NOLs 6,008 4,752 Tax credit carryforwards 5,374 4,651 Charitable contribution 2,233 1,764 Valuation allowance (6,102 ) (6,579 ) Total deferred tax assets 53,627 41,575 Deferred tax liabilities: Depreciation and amortization (126,174 ) (117,286 ) Other liabilities (1,459 ) (1,811 ) Total deferred tax liabilities (127,633 ) (119,097 ) Net deferred tax liabilities $ (74,006 ) $ (77,522 ) As reported in the balance sheet: Net current deferred tax assets (included in other current assets) $ — $ 14,485 Net noncurrent deferred tax liabilities (74,006 ) (92,007 ) Net deferred tax liabilities $ (74,006 ) $ (77,522 ) Deferred tax assets relate primarily to reserves and other liabilities for costs and expenses not currently deductible for tax purposes as well as net operating loss and other carryforwards. Deferred tax liabilities relate primarily to the cumulative difference between book depreciation and amounts deducted for tax purposes. With the exception of foreign net operating loss carryforwards and foreign tax credits, a valuation allowance has not been recorded to reduce the balance of deferred tax assets at either December 31, 2015, or December 31, 2014, because the Company believes that it is more likely than not that the deferred income tax assets will ultimately be realized. As discussed in Note 1, the Company elected to early adopt guidance which requires that deferred tax liabilities and assets be classified as noncurrent in the balance sheet on a prospective basis and therefore, prior years were not retrospectively adjusted. Had the guidance not been adopted in the current year, $8,953 in deferred tax assets would have been presented as current in our Consolidated Balance Sheets as of December 31, 2015.

Share-Based Compensation

Share-Based Compensation	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Share-Based Compensation	11. SHARE-BASED COMPENSATION The Company’s 2007 Long-Term Incentive Plan (“Incentive Plan”) permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to its employees and directors for up to 5,800 shares of common stock. The Company also issues share-based compensation as inducement awards to new employees upon approval of the Board of Directors. Compensation cost charged to expense related to share-based compensation arrangements was $4,040, $2,694 and $3,251, for the years ended December 31, 2015, 2014 and 2013, respectively. Non-qualified stock options The NQSO awards were granted with an exercise price equal to the market price of the Company’s common stock at the date of grant. The option awards generally vest in three equal annual installments commencing on the first anniversary of the grant date, and have ten year exercise periods. The fair value of the NQSOs was determined at the grant date using a Black-Scholes option pricing model, which requires the Company to make several assumptions. The risk-free interest rate is based on the U.S. Treasury yield curve in effect for the expected term of the option at the time of grant. The annual dividend yield on the Company’s common stock is based on estimates of future dividends during the expected term of the NQSOs. The expected life of the NQSOs was determined from historical exercise data providing a reasonable basis upon which to estimate the expected life. For grants issued in 2014 and 2013, the volatility assumptions were based on historical volatility of Great Lakes. There is not an active market for options on the Company’s common stock and, as such, implied volatility for the Company’s stock was not considered. Additionally, the Company’s general policy is to issue new shares of registered common stock to satisfy stock option exercises or grants of restricted stock. No NQSO awards were granted in 2015. The weighted-average grant-date fair value of options granted during the years ended December 31, 2014 and 2013 was $4.23 and $4.06 respectively. The fair value of each option was estimated using the following assumptions: 2014 2013 Expected volatility 53.9 % 58.2 % Expected dividends 0.0 % 0.0 % Expected term (in years) 7.0 6.0 Risk free rate 1.9 % 1.0 % A summary of stock option activity under the Incentive Plan as of December 31, 2015, and changes during the year ended December 31, 2015, is presented below: Options Shares Weighted Exercise Price Weighted-Average Remaining Contract Term (yrs) Aggregate Intrinsic Value ($000's) Outstanding as of January 1, 2015 1,889 $ 6.31 Granted — — Exercised (86 ) 5.35 Forfeited or Expired (77 ) 7.14 Outstanding as of December 31, 2015 1,726 $ 6.32 Vested at December 31, 2015 1,447 $ 6.07 5.3 $ 17 Vested or expected to vest at December 31, 2015 1,724 $ 6.32 5.8 $ 17 Restricted stock units RSUs generally vest in one installment on the third anniversary of the grant date. The fair value of RSUs was based upon the Company’s stock price on the date of grant. A summary of the status of the Company’s non-vested RSUs as of December 31, 2015, and changes during the year ended December 31, 2015, is presented below: Nonvested Restricted Stock Units Shares Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2015 2,063 $ 6.91 Granted 784 5.65 Vested (160 ) 6.42 Forfeited (491 ) 6.79 Outstanding as of December 31, 2015 2,196 $ 6.57 Expected to vest at December 31, 2015 1,140 $ 6.37 As of December 31, 2015, there was $5,234 of total unrecognized compensation cost related to non-vested NQSOs and RSUs granted under the Plan. That cost for non-vested NQSOs and RSUs is expected to be recognized over a weighted-average period of 1.1 years and 2.8 years, respectively. The Incentive Plan permits the employee to use vested shares from RSUs to satisfy the grantee’s U.S. federal income tax liability resulting from the issuance of the shares through the Company’s retention of that number of common shares having a market value as of the vesting date equal to such tax obligation up to the minimum statutory withholding requirements. The amount related to shares used for such tax withholding obligations was approximately $267 and $497 for the years ended December 31, 2015 and 2014, respectively. Director compensation The Company uses a combination of cash and share-based compensation to attract and retain qualified candidates to serve on our Board of Directors. Compensation is paid to non-employee directors. Directors who are employees receive no additional compensation for services as members of the Board or any of its committees. All of our directors are non-employee directors with the exception of Mr. Berger. Share-based compensation is paid pursuant to the Incentive Plan. Each non-employee director of the Company receives an annual retainer of $155, payable quarterly in arrears, and is paid 50% in cash and 50% in common stock of the Company. The Chairman of the Board receives an additional $150 of annual compensation, paid 50% in cash and 50% in common stock. In the years ended December 31, 2015, 2014 and 2013, 112 thousand, 99 thousand and 96 thousand shares, respectively, of the Company’s common stock were issued to non-employee directors under the Incentive Plan.

Retirement Plans

Retirement Plans	12 Months Ended
	Dec. 31, 2015
Compensation And Retirement Disclosure [Abstract]
Retirement Plans	12. RETIREMENT PLANS The Company sponsors four 401(k) savings plans, one covering substantially all non-union salaried employees (“Salaried Plan”), a second covering its hourly employees (“Hourly Plan”), a third plan specifically for its employees that are members of a tugboat union and a fourth for the salary and non-union employees of certain subsidiaries (“Affiliated Plan”). Under the Salaried Plan, the Hourly Plan and the Affiliated Plan, individual employees may contribute a percentage of compensation and the Company will match a portion of the employees’ contributions. The Salaried Plan and Affiliated Plan also include a discretionary profit-sharing component, permitting the Company to make discretionary employer contributions to all eligible employees of these plans. Additionally, the Company sponsors a Supplemental Savings Plan in which the Company makes contributions for certain key executives. The Company’s expense for matching, discretionary and Supplemental Savings Plan contributions for 2015, 2014 and 2013, was $6,772, $5,256 and $5,123, respectively. The Company also contributes to various multiemployer pension plans pursuant to collective bargaining agreements. In 2015, 2014 and 2013, the Company contributed $4,990, $4,383 and $3,870 respectively to all of the multiemployer plans that provide pension benefits in our continuing operations. The information available to the Company about the multiemployer plans in which it participates, whether via request to the plan or publicly available, is generally dated due to the nature of the reporting cycle of multiemployer plans and legal requirements under the Employee Retirement Income Security Act (“ERISA”) as amended by the Multiemployer Pension Plan Amendments Act (“MPPAA”). Based upon these plans’ most recently available annual reports, the Company’s contributions to these plans were less than 5% of each plan’s total contributions. The Company does not expect any future increased contributions to have a material negative impact on its financial position, results of operations or cash flows for future years. The risks of participating in multiemployer plans are different from single employer plans as assets contributed are available to provide benefits to employees of other employers and unfunded obligations from an employer that discontinues contributions are the responsibility of all remaining employers. In addition, in the event of a plan’s termination or the Company’s withdrawal from a plan, the Company may be liable for a portion of the plan’s unfunded vested benefits. However, information from the plans’ administrators is not available to permit the Company to determine its share, if any, of unfunded vested benefits.

Commitments And Contingencies

Commitments And Contingencies	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Commitments And Contingencies	13. COMMITMENTS AND CONTINGENCIES Commercial commitments Performance and bid bonds are customarily required for dredging and marine construction projects, as well as some environmental & remediation projects. The Company has a bonding agreement with Zurich American Insurance Company (“Zurich”) under which the Company can obtain performance, bid and payment bonds. In April 2015, we entered into additional bonding agreements with ACE Holdings, Inc., Argonaut Insurance Company, Berkley Insurance Company, and Liberty Mutual Insurance Company (collectively, the “Additional Sureties”). The bonding agreements with the Additional Sureties contain similar terms and conditions as the Zurich bonding agreement. In connection with the sale of our historic 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. 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. 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. Under the terms of the divestiture, the Company retained certain pre-closing liabilities relating to the disposed business. Certain of these liabilities and a legal action brought by the Company to enforce the buyer’s obligations under the sale agreement are described below. In 2009, NASDI received a letter stating that the Attorney General for the Commonwealth of Massachusetts is investigating alleged violations of the Massachusetts Solid Waste Act. The Company believes that the Massachusetts Attorney General is investigating waste disposal activities at an allegedly unpermitted disposal site owned by a third party with whom NASDI contracted for the disposal of waste materials in 2007 and 2008. Per the Massachusetts Attorney General’s request, NASDI executed a tolling agreement regarding the matter in 2009 and engaged in further discussions with the Massachusetts Attorney General’s office. On or about February 5, 2016, the parties agreed to a tentative settlement in the amount of $275, subject to final documentation. 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 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 and intends to vigorously defend against the counterclaims. In 2012, the Company contracted with a shipyard to perform the functional design drawings, detailed design drawings and follow on construction of a new Articulated Tug & Barge (“ATB”) Trailing Suction Hopper Dredge. In April 2013, the Company terminated the contract with the shipyard for default and the counterparty sent the Company a notice requesting arbitration under the contract with respect to the Company’s termination for default, including but not limited to the Company’s right to draw on letters of credit that had been issued by the shipyard as financial security required by the contract. In May 2013, the Company drew upon the shipyard’s letters of credit related to the contract and received $13,600. Arbitration proceedings were initiated. In January 2014, the Company and the shipyard executed a settlement agreement pursuant to which the Company retained $10,500 of the proceeds of the financial security and remitted $3,100 of those funds to the shipyard, all other claims were released, and the arbitration was dismissed with prejudice. 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 2025. 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 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 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. Future minimum operating lease payments at December 31, 2015, are as follows: 2016 $ 22,516 2017 20,800 2018 13,034 2019 8,802 2020 6,246 Thereafter 10,866 Total minimum operating lease payments $ 82,264 Total rent expense under long-term operating lease arrangements for the years ended December 31, 2015, 2014 and 2013 was $21,697, $25,318 and $21,620, respectively. This excludes expenses for equipment and facilities rented on a short-term, as-needed basis.

Investments

Investments	12 Months Ended
	Dec. 31, 2015
Equity Method Investments And Joint Ventures [Abstract]
Investments	14. INVESTMENTS Amboy Aggregates The Company and a New Jersey aggregates company each own 50% of Amboy Aggregates (“Amboy”). Amboy was formed in December 1984 to mine sand from the entrance channel to New York Harbor to provide sand and aggregate for use in road and building construction and for clean land fill. Amboy sold its interest in a stone import business and its holdings in land during 2014 and is winding down operations. The land owned in conjunction with Lower Main Street Development, LLC (“Lower Main”) was sold for a combined gain of $29,729. The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ 139 $ 13,784 $ 24,399 Gross profit (1,363 ) (118 ) 4,142 Income (loss) from continuing operations (3,152 ) 11,326 2,329 Net income (loss) (3,152 ) 9,527 3,998 Lower Main Street Development The Company and a New Jersey aggregates company each own 50% of Lower Main. Lower Main was organized in February 2003 to hold land for development or sale. This land owned in conjunction with Amboy Aggregates was sold in 2014. Lower Main is winding down operations. The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ — $ 180 $ 180 Gross profit — 180 180 Net income 28 14,803 175 TerraSea Environmental Solutions The Company owns 50% of TerraSea Environmental Solutions (“TerraSea”) as a joint venture. TerraSea is engaged in the environmental services business through its ability to remediate contaminated soil and dredged sediment treatment. At December 31, 2015 and December 31, 2014, the Company had net advances to TerraSea of $27,592 and $22,898, respectively, which are recorded in other current assets. The Company has an accumulated deficit in joint ventures, which represents losses recognized to date in excess of our investment in TerraSea, of $14,271 and $10,383 at December 31, 2015 and December 31, 2014, respectively, which is presented in accrued expenses. The Company has commenced the wind down of TerraSea with its joint venture partner. The Company believes its net advances to TerraSea are ultimately recoverable either through the operations of the joint venture or as an obligation of our joint venture partner. The joint venture partner has notified the Company that it disagrees with the amount of net advances to TerraSea. The Company believes that its joint venture partner remains obligated for its share of net advances, and any future advances necessary to complete TerraSea’s remaining project. During July 2015, the Company proposed taking a larger percent of the loss on a TerraSea project. Based on this proposal, the Company accrued $1,983 for the year ended December 31, 2015representing the estimated share of additional losses to be assumed. The joint venture partner and the Company are continuing discussions. If those discussions do not lead to a resolution satisfactory to both parties, the joint venture partner and the Company will go to binding arbitration as stipulated by the TerraSea operating agreement. To the extent that net advances are not fully recoverable, additional losses may result in future periods. The Company and its joint venture partner remained obligated to fund TerraSea through the completion of its remaining project which occurred in 2015. The remaining TerraSea project was substantially complete at December 31, 2015. The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ 6,960 $ 11,278 $ 7,368 Gross profit (3,800 ) (19,153 ) (956 ) Net income (loss) (3,800 ) (19,856 ) (956 )

Related Party Transactions

Related Party Transactions	12 Months Ended
	Dec. 31, 2015
Related Party Transactions [Abstract]
Related Party Transactions	15. RELATED-PARTY TRANSACTIONS The historical demolition business was operated out of a building owned by a former minority interest owner in Yankee and prior to 2011, a profits interest owner in NASDI. In 2014 and 2013, NASDI and Yankee paid the minority interest owner $375 and $449, respectively, for rent and property taxes. In conjunction with the sale of NASDI and Yankee (See Note 16), the lease was terminated as of October 31, 2014, and the Company also paid $490 in lease termination fees. There were no rents paid related to this building in 2015. In 2013, our rivers & lakes group operated out of facilities owned by the former owner of the group. The Company paid $95 in rent to the building owner during 2013. As the rivers & lakes group relocated to a new facility in late 2013, there were no rents paid in 2014 or 2015. Our Terra Contracting business operates out of two facilities owned by the former owner of Terra Contracting, LLC. The Company paid $243 for rent on these two properties in each of 2015, 2014 and 2013. Our Magnus Pacific business operates out of two facilities owned by Magnus Real Estate Group, LLC, which is owned by the formers owners of Magnus Pacific. In 2015 and 2014, the Company paid rent of $402 and $46, respectively, for these two properties. As the purchase of Magnus Pacific Corporation occurred in late 2014, there were no rents paid in 2013.

Business Dispositions

Business Dispositions	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Business Dispositions	16. BUSINESS COMBINATIONS AND DISPOSITIONS Discontinued operations On April 23, 2014, the Company entered into an agreement and completed the sale of NASDI, LLC and Yankee Environmental Services, LLC, its two former subsidiaries that comprised the historical demolition business. 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, including recovery of outstanding claims for additional compensation from customers, and net of future payments of accounts payable existing at the date of close, including any future payments of obligations associated with outstanding claims. In the fourth quarter of 2013, the Company recorded a preliminary loss on disposal of assets held for sale in discontinued operations. The loss on disposal is subject to change based on the value of additional proceeds received on the working capital existing at the date of disposition. The amount and timing of the working capital settlement and the amount and timing of the realization of additional net proceeds may be impacted by the litigation with the buyer of the historical demolition business (see Note 13). However, management believes that the ultimate resolution of these matters will not be material to the Company’s consolidated financial position or results of operations. The results of the businesses have been reported in discontinued operations as follows: 2014 2013 Revenue $ 14,803 $ 39,550 Loss before income taxes from discontinued operations $ (19,167 ) $ (55,530 ) Loss on disposal of assets held for sale — (18,436 ) Income tax benefit 8,744 19,116 Loss from discontinued operations, net of income taxes $ (10,423 ) $ (54,850 ) Magnus Pacific acquisition On November 4, 2014, the Company acquired Magnus Pacific Corporation, a California corporation, for an aggregate purchase price of approximately $40 million. Magnus Pacific Corporation is engaged in the business of environmental remediation, geotechnical construction, demolition, and sediments and wetlands construction. Under the terms of the acquisition, the aggregate purchase price is satisfied by payment of $25,000 paid at closing, the issuance of a promissory note and an earnout payment. In the event Magnus Pacific (“Magnus”) did not achieve minimum earnings before interest, taxes, depreciation and amortization, as adjusted in the 2015 fiscal year, the principal amount of the promissory note would be reduced. Magnus did not reach the minimum EBITDA threshold for 2015 designated in the secured promissory note; therefore, during the second quarter of 2015, the Company reduced the remaining fair value by $7,013 to zero and the corresponding change was reflected in general and administrative expenses. The maximum potential aggregate earnout payment is $11,400 (the “Earnout Payment”) and will be determined based on the attainment of combined Adjusted EBITDA targets of Magnus and Terra Contracting Services, LLC (“Terra”), a wholly-owned subsidiary of the Company for the year ending December 31, 2019. The Earnout Payment may be paid in cash or shares of the Company’s common stock, at the Company’s option. At December 31, 2015 and 2014, the fair value of the recorded earnout liability was $8,457 and $8,024, respectively, which is recorded in other liabilities. The preliminary purchase price has been allocated to the assets acquired and liabilities assumed using estimated fair values as of the acquisition date. Tangible assets acquired of $57,303 primarily were receivables and contract revenues in excess of billings of $41,067 and property and equipment of $11,573. Finite-lived intangible assets acquired of $8,422 were primarily related to acquired backlog and also include a non-compete agreement, patents and trade names. The acquired backlog was amortized on a straight-line basis over one year while all other finite-lived intangible assets are being amortized on a straight-line basis over five years. Liabilities assumed of $27,586, includes primarily $20,732 of accounts payable. Goodwill of $7,000 represents the excess of cost over the fair value of the net tangible and intangible assets acquired and is included in the environmental & remediation segment. Concurrent with the closing of the acquisition of Magnus Pacific Corporation, the Company granted restricted stock unit awards to the shareholders representing the right to receive, in aggregate, up to 1,500 shares of Great Lakes’ common stock. Each award vests on March 31, 2020, subject to the applicable employee’s continuous employment with Great Lakes through such date and satisfaction of certain business milestones. As the acquisition took place on November 4, 2014, no income or earnings of Magnus were included in the consolidated statement of operations of the Company for the periods ended December 31, 2013. The following unaudited pro forma financial information presents the consolidated results of operations of the Company as they may have appeared had the acquisition described above occurred as of January 1, 2013 for purposes of the unaudited pro forma consolidated statements of operations. The unaudited pro forma consolidated financial information are provided for illustrative purposes only and do not purport to present what the actual results of operations would have been had the transaction actually occurred on the date indicated, nor does it purport to represent results of operations for any future period. The information does not reflect any cost savings or benefits that may be obtained through synergies among the operations of the Company. 2014 2013 (Unaudited) Revenue as reported $ 806,831 $ 731,418 Revenue of purchased businesses for the period prior to the acquisition 106,723 87,943 Pro forma revenue $ 913,554 $ 819,361 Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ 10,295 $ (34,361 ) Net income of Magnus including net income prior to acquisition and pro forma acquisition accounting adjustments 6,328 1,069 Pro forma net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ 16,623 $ (33,292 ) The pro forma adjustments to net income represent amortization of intangibles established in purchase accounting, interest on the debt used to purchase Magnus and taxes on net income at the Company’s effective tax rate, all applied to the period prior to acquisition. Other The Company recorded a $2,197 noncash bargain purchase gain on a small asset acquisition in 2014.

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Information	17. SEGMENT INFORMATION The Company and its subsidiaries currently operate in two reportable segments: dredging and environmental & remediation. The Company’s financial reporting systems present various data for management to run the business, including profit and loss statements prepared according to the segments presented. Management uses operating income to evaluate performance between the two segments. Segment information for 2015, 2014 and 2013, is provided as follows: 2015 2014 2013 Dredging: Contract revenues $ 681,255 $ 697,711 $ 642,602 Operating income 64,073 41,620 54,683 Depreciation and amortization 50,556 43,620 44,118 Total assets 875,797 815,683 821,253 Property and equipment—net 397,468 366,027 330,689 Goodwill 76,576 76,576 76,576 Investment in joint ventures 1 2,114 8,256 Capital expenditures 82,000 79,186 57,902 Environmental & remediation: Contract revenues 181,710 114,412 94,840 Operating loss (41,114 ) (17,767 ) (3,282 ) Depreciation and amortization 14,029 6,509 2,504 Total assets 127,907 134,324 98,505 Property and equipment—net 32,742 33,418 14,931 Goodwill 7,000 9,750 2,750 Investment in joint ventures 3,760 5,775 — Capital expenditures 7,279 12,892 4,100 Intersegment: Contract revenues (6,087 ) (5,292 ) (6,024 ) Total assets (102,080 ) (56,773 ) (67,113 ) Total: Contract revenues 856,878 806,831 731,418 Operating income 22,959 23,853 51,401 Depreciation and amortization 64,585 50,129 46,622 Total assets 901,625 893,234 852,645 Property and equipment—net 430,210 399,445 345,620 Goodwill 83,576 86,326 79,326 Investment in joint ventures 3,761 7,889 8,256 Capital expenditures 89,279 92,078 62,002 The Company classifies the revenue related to its dredging projects into the following types of work: 2015 2014 2013 Capital dredging — U.S. $ 207,058 $ 195,635 $ 153,781 Capital dredging — foreign 139,945 155,000 138,436 Coastal protection dredging 184,060 194,219 228,868 Maintenance dredging 120,055 123,923 90,833 Rivers & lakes 30,137 28,934 30,684 Total dredging $ 681,255 $ 697,711 $ 642,602 The Company derived revenues and gross profit from foreign project operations for the years ended December 31, 2015, 2014, and 2013, as follows: 2015 2014 2013 Contract revenues $ 139,945 $ 155,000 $ 138,436 Costs of contract revenues (105,951 ) (118,682 ) (117,029 ) Gross profit $ 33,994 $ 36,318 $ 21,407 In 2015, foreign revenues were primarily from work done in the Middle East and Brazil. In 2014 and 2013, the majority of the Company’s foreign revenue came from the Wheatstone LNG project in Western Australia and from projects in the Middle East. The majority of the Company’s long-lived assets are marine vessels and related equipment. At any point in time, the Company may employ certain assets outside of the U.S., as needed, to perform work on the Company’s foreign projects. As of December 31, 2015 and 2014, long-lived assets with a net book value of $83,397 and $93,839, respectively, were located outside of the U.S. The Company’s primary customer is the U.S. Army Corps of Engineers (the “Corps”), which has responsibility for federally funded projects related to waterway navigation and flood control. In 2015, 2014 and 2013, 51.0%, 60.4% and 45.0%, respectively, of contract revenues were earned from contracts with federal government agencies, including the Corps, as well as other federal entities such as the U.S. Coast Guard and U.S. Navy. At December 31, 2015 and 2014, approximately 24.9% and 45.9%, respectively, of accounts receivable, including contract revenues in excess of billings and retainage, were due on contracts with federal government agencies. The Company depends on its ability to continue to obtain federal government contracts, and indirectly, on the amount of federal funding for new and current government dredging projects. Therefore, the Company’s operations can be influenced by the level and timing of federal funding. The Company recognized a loss on a landfill project of $7,446 on which the change in estimate to the gross profit percentage in the year resulted in a cumulative net impact on the project margin, which decreased gross profit by extensively the entire amount of the loss in the year ended December 31, 2015. The project was substantially complete in early 2016. In 2014, the Company earned significant revenue from a large, single customer foreign contract. A revision to the estimated gross profit percentage was recognized in the year resulting in a cumulative net impact on the project margin, which increased gross profit by $22,418 for the year ended December 31, 2014, including an increase in gross profit of $7,645 during the fourth quarter. The project was completed in 2014. Revenue from foreign projects has been concentrated in the Middle East which comprised 14.7% of total revenue in 2015. At December 31, 2015 and 2014, approximately 24.6% and 13.3%, respectively, of total accounts receivable, including retainage and contract revenues in excess of billings, were due on contracts in the Middle East. There is a dependence on future projects in the Middle East, as vessels are currently located there. However, some of the vessels located in Middle East can be moved back to the U.S. or all can be moved to other international markets as opportunities arise.

Subsidiary Guarantors

Subsidiary Guarantors	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Subsidiary Guarantors	18. SUBSIDIARY GUARANTORS The Company’s long-term debt at December 31, 2015 includes $275,000 of 7.375% senior notes due February 1, 2019. The Company’s obligations under these senior unsecured notes are guaranteed by the Company’s 100% owned domestic subsidiaries. Such guarantees are full, unconditional and joint and several. The following supplemental financial information sets forth for the Company’s subsidiary guarantors (on a combined basis), the Company’s non-guarantor subsidiaries (on a combined basis) and Great Lakes Dredge & Dock Corporation, exclusive of its subsidiaries (“GLDD Corporation”): (i) balance sheets as of December 31, 2015 and 2014; (ii) statements of operations and comprehensive income (loss) for the years ended December 31, 2015, 2014 and 2013; and (iii) statements of cash flows for the years ended December 31, 2015, 2014 and 2013. GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET AS OF DECEMBER 31, 2015 (In thousands) ASSETS Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated CURRENT ASSETS: Cash and cash equivalents $ 12,035 $ 2,147 $ 2 $ — $ 14,184 Accounts receivable — net 129,978 799 — — 130,777 Contract revenues in excess of billings 79,477 1,718 — — 81,195 Inventories 35,963 — — — 35,963 Prepaid expenses 7,924 — — — 7,924 Other current assets 58,995 218 477 — 59,690 Total current assets 324,372 4,882 479 — 329,733 PROPERTY AND EQUIPMENT—Net 430,192 18 — — 430,210 GOODWILL 83,576 — — — 83,576 OTHER INTANGIBLE ASSETS—Net 2,428 — — — 2,428 INVENTORIES — Noncurrent 41,646 — — — 41,646 INVESTMENTS IN JOINT VENTURES 3,761 — — — 3,761 RECEIVABLES FROM AFFILIATES 18,326 6,009 70,738 (95,073 ) — INVESTMENTS IN SUBSIDIARIES 3,706 — 621,984 (625,690 ) — OTHER 6,702 3 3,566 — 10,271 TOTAL $ 914,709 $ 10,912 $ 696,767 $ (720,763 ) $ 901,625 LIABILITIES AND EQUITY CURRENT LIABILITIES: Accounts payable $ 118,619 $ 227 $ — $ — $ 118,846 Accrued expenses 62,861 509 8,907 — 72,277 Billings in excess of contract revenues 6,964 97 — — 7,061 Current portion of long term debt 1,424 — 6,082 — 7,506 Total current liabilities 189,868 833 14,989 — 205,690 7 3/8% SENIOR NOTES — — 274,909 — 274,909 REVOLVING CREDIT FACILITY — — 20,000 — 20,000 NOTE PAYABLE 323 — 54,059 — 54,382 DEFERRED INCOME TAXES (783 ) — 74,789 — 74,006 PAYABLES TO AFFILIATES 85,859 3,505 5,709 (95,073 ) — OTHER 20,326 — 139 — 20,465 Total liabilities 295,593 4,338 444,594 (95,073 ) 649,452 TOTAL EQUITY 619,116 6,574 252,173 (625,690 ) 252,173 TOTAL $ 914,709 $ 10,912 $ 696,767 $ (720,763 ) $ 901,625 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET AS OF DECEMBER 31, 2014 (In thousands) ASSETS Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated CURRENT ASSETS: Cash and cash equivalents $ 41,724 $ 663 $ 2 $ — $ 42,389 Accounts receivable — net 115,739 355 — (2,906 ) 113,188 Receivables from affiliates 152,822 3,673 55,805 (212,300 ) — Contract revenues in excess of billings 78,631 4,236 — (310 ) 82,557 Inventories 34,735 — — — 34,735 Prepaid expenses 4,708 — — — 4,708 Other current assets 49,619 431 14,617 — 64,667 Total current assets 477,978 9,358 70,424 (215,516 ) 342,244 PROPERTY AND EQUIPMENT—Net 399,421 24 — — 399,445 GOODWILL 86,326 — — — 86,326 OTHER INTANGIBLE ASSETS—Net 8,963 — — — 8,963 INVENTORIES — Noncurrent 36,262 — — — 36,262 INVESTMENTS IN JOINT VENTURES 7,889 — — — 7,889 INVESTMENTS IN SUBSIDIARIES 3,757 — 619,220 (622,977 ) — OTHER 7,135 3 4,967 — 12,105 TOTAL $ 1,027,731 $ 9,385 $ 694,611 $ (838,493 ) $ 893,234 LIABILITIES AND EQUITY CURRENT LIABILITIES: Accounts payable $ 121,282 $ 1,389 $ 516 $ (3,216 ) $ 119,971 Payables to affiliates 196,829 403 15,068 (212,300 ) — Accrued expenses 60,415 659 8,967 — 70,041 Billings in excess of contract revenues 4,639 — — — 4,639 Current portion of long term debt 859 — 5,000 — 5,859 Total current liabilities 384,024 2,451 29,551 (215,516 ) 200,510 7 3/8% SENIOR NOTES — — 274,880 — 274,880 NOTE PAYABLE 7,553 — 41,944 — 49,497 DEFERRED INCOME TAXES 172 — 91,835 — 92,007 OTHER 19,939 — 438 — 20,377 Total liabilities 411,688 2,451 438,648 (215,516 ) 637,271 TOTAL EQUITY 616,043 6,934 255,963 (622,977 ) 255,963 TOTAL $ 1,027,731 $ 9,385 $ 694,611 $ (838,493 ) $ 893,234 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME FOR THE YEAR ENDED DECEMBER 31, 2015 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals Contract revenues $ 845,889 $ 13,698 $ — $ (2,709 ) $ 856,878 Costs of contract revenues (750,509 ) (13,155 ) — 2,709 (760,955 ) Gross profit 95,380 543 — — 95,923 OPERATING EXPENSES: General and administrative expenses 71,069 — — — 71,069 Impairment of goodwill 2,750 — — — 2,750 Gain on sale of assets—net (855 ) — — — (855 ) Operating income 22,416 543 — — 22,959 Interest income (expense)—net (526 ) — (23,839 ) — (24,365 ) Equity in earnings of subsidiaries 8 — 16,282 (16,290 ) — Equity in loss of joint ventures (6,051 ) — — — (6,051 ) Other expense (1,222 ) (7 ) — — (1,229 ) Income (loss) before income taxes 14,625 536 (7,557 ) (16,290 ) (8,686 ) Income tax (provision) benefit 1,505 (376 ) 1,368 — 2,497 Net income (loss) $ 16,130 $ 160 $ (6,189 ) $ (16,290 ) $ (6,189 ) Comprehensive income (loss) $ 16,130 $ (1,089 ) $ (7,438 ) $ (15,041 ) $ (7,438 ) GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME FOR THE YEAR ENDED DECEMBER 31, 2014 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals Contract revenues $ 799,579 $ 26,282 $ — $ (19,030 ) $ 806,831 Costs of contract revenues (707,474 ) (25,891 ) — 19,030 (714,335 ) Gross profit 92,105 391 — — 92,496 OPERATING EXPENSES: General and administrative expenses 67,905 6 — — 67,911 Loss on sale of assets—net 732 — — — 732 Operating income 23,468 385 — — 23,853 Interest income (expense)—net 61 (261 ) (19,767 ) — (19,967 ) Equity in earnings of subsidiaries 20 — 10,373 (10,393 ) — Equity in earnings of joint ventures 2,895 — — — 2,895 Gain on bargain purchase acquisition 2,197 — — — 2,197 Other income 203 7 — — 210 Income (loss) from continuing operations before income taxes 28,844 131 (9,394 ) (10,393 ) 9,188 Income tax (provision) benefit (18,173 ) (409 ) 30,112 — 11,530 Income (loss) from continuing operations 10,671 (278 ) 20,718 (10,393 ) 20,718 Loss from discontinued operations, net of income taxes (10,423 ) (1,343 ) (10,423 ) 11,766 (10,423 ) Net income (loss) $ 248 $ (1,621 ) $ 10,295 $ 1,373 $ 10,295 Comprehensive income (loss) $ 49 $ (1,683 ) $ 10,034 $ 1,634 $ 10,034 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME FOR THE YEAR ENDED DECEMBER 31, 2013 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Corporation Eliminations Consolidated Totals Contract revenues $ 718,041 $ 24,932 $ — $ (11,555 ) $ 731,418 Costs of contract revenues (614,908 ) (27,770 ) — 11,555 (631,123 ) Gross profit 103,133 (2,838 ) — — 100,295 OPERATING EXPENSES: General and administrative expenses 68,029 10 — — 68,039 Proceeds from loss of use claim (13,372 ) — — — (13,372 ) (Gain) loss on sale of assets—net (5,775 ) — 2 — (5,773 ) Operating income (loss) 54,251 (2,848 ) (2 ) — 51,401 Interest income (expense)—net (136 ) (256 ) (21,549 ) — (21,941 ) Equity in earnings of subsidiaries 212 — 59,477 (59,689 ) — Equity in earnings of joint ventures 1,208 — — — 1,208 Other expense (3 ) (348 ) — — (351 ) Income (loss) from continuing operations before income taxes 55,532 (3,452 ) 37,926 (59,689 ) 30,317 Income tax (provision) benefit 293 4 (10,757 ) — (10,460 ) Income (loss) from continuing operations 55,825 (3,448 ) 27,169 (59,689 ) 19,857 Loss from discontinued operations, net of income taxes (55,106 ) (1,448 ) (62,162 ) 63,866 (54,850 ) Net income (loss) 719 (4,896 ) (34,993 ) 4,177 (34,993 ) Net loss attributable to noncontrolling interests — — 632 — 632 Net income (loss) attributable to Great Lakes Dredge & Dock Corporation $ 719 $ (4,896 ) $ (34,361 ) $ 4,177 $ (34,361 ) Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation $ 1,023 $ (5,293 ) $ (34,454 ) $ 4,270 $ (34,454 ) GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE YEAR ENDED DECEMBER 31, 2015 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals OPERATING ACTIVITIES: Cash provided by (used in) operating activities $ 52,498 $ 312 $ (23,688 ) $ — $ 29,122 INVESTING ACTIVITIES: Purchases of property and equipment (74,455 ) — — — (74,455 ) Proceeds from dispositions of property and equipment 1,322 — — — 1,322 Net change in accounts with affiliates (29,402 ) — (12,222 ) 41,624 — Cash used in investing activities (102,535 ) — (12,222 ) 41,624 (73,133 ) FINANCING ACTIVITIES: Proceeds from term loan facility — — 2,640 — 2,640 Repayments of term loan facility — — (5,000 ) — (5,000 ) Deferred financing fees — — (111 ) — (111 ) Repayment of long term note payable — — (443 ) — (443 ) Taxes paid on settlement of vested share awards — — (267 ) — (267 ) Net change in accounts with affiliates 4,291 1,269 36,064 (41,624 ) — Capital contributions 17,258 — (17,258 ) — — Proceeds from equipment debt — — 410 — 410 Repayments of equipment debt (1,201 ) — — — (1,201 ) Exercise of stock options and purchases from employee stock plans — — 1,365 — 1,365 Excess income tax benefit from share-based compensation — — (57 ) — (57 ) Purchase of treasury stock — — (1,433 ) — (1,433 ) Borrowings under revolving loans — — 179,500 — 179,500 Repayments of revolving loans — — (159,500 ) — (159,500 ) Cash provided by financing activities 20,348 1,269 35,910 (41,624 ) 15,903 Effect of foreign currency exchange rates on cash and cash equivalents — (97 ) — — (97 ) Net increase (decrease) in cash and cash equivalents (29,689 ) 1,484 — — (28,205 ) Cash and cash equivalents at beginning of period 41,724 663 2 — 42,389 Cash and cash equivalents at end of period $ 12,035 $ 2,147 $ 2 $ — $ 14,184 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE YEAR ENDED DECEMBER 31, 2014 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals OPERATING ACTIVITIES: Net cash flows provided by operating activities of continuing operations $ 63,276 $ 999 $ 2,879 $ — $ 67,154 Net cash flows used in operating activities of discontinued operations (17,328 ) (1,024 ) — — (18,352 ) Cash provided by (used in) operating activities 45,948 (25 ) 2,879 — 48,802 INVESTING ACTIVITIES: Purchases of property and equipment (91,910 ) — — — (91,910 ) Proceeds from dispositions of property and equipment 68 — — — 68 Payments for acquisitions of businesses (2,048 ) — (25,000 ) — (27,048 ) Proceeds from vendor performance obligations (3,100 ) — — — (3,100 ) Net change in accounts with affiliates 68,187 — — (68,187 ) — Net cash flows used in investing activities of continuing operations (28,803 ) — (25,000 ) (68,187 ) (121,990 ) Net cash flows provided by investing activities of discontinued operations 5,275 — — — 5,275 Cash used in investing activities (23,528 ) — (25,000 ) (68,187 ) (116,715 ) FINANCING ACTIVITIES: Proceeds from term loan facility — — 47,360 — 47,360 Repayments of term loan facility — — (417 ) — (417 ) Proceeds from issuance of 7 3/8% senior notes — — 24,880 — 24,880 Deferred financing fees — — (2,532 ) — (2,532 ) Taxes paid on settlement of vested share awards — — (497 ) — (497 ) Purchase of noncontrolling interest — — (205 ) — (205 ) Net change in accounts with affiliates — (2,547 ) (65,640 ) 68,187 — Intercompany dividends (52,400 ) — 52,400 — — Repayments of equipment debt (235 ) — — — (235 ) Exercise of stock options and purchases from employee stock plans — — 1,568 — 1,568 Excess income tax benefit from share-based compensation — — 206 — 206 Borrowings under revolving loans — — 236,500 — 236,500 Repayments of revolving loans — — (271,500 ) — (271,500 ) Cash provided by (used in) financing activities (52,635 ) (2,547 ) 22,123 68,187 35,128 Effect of foreign currency exchange rates on cash and cash equivalents — (164 ) — — (164 ) Net increase (decrease) in cash and cash equivalents (30,215 ) (2,736 ) 2 — (32,949 ) Cash and cash equivalents at beginning of period 71,939 3,399 — — 75,338 Cash and cash equivalents at end of period $ 41,724 $ 663 $ 2 $ — $ 42,389 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE YEAR ENDED DECEMBER 31, 2013 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Corporation Eliminations Consolidated Totals OPERATING ACTIVITIES: Net cash flows provided by (used in) operating activities of continuing operations $ 126,736 $ (7,748 ) $ (32,641 ) $ — $ 86,347 Net cash flows used in operating activities of discontinued operations (5,049 ) (6,475 ) — — (11,524 ) Cash provided by (used in) operating activities 121,687 (14,223 ) (32,641 ) — 74,823 INVESTING ACTIVITIES: Purchases of property and equipment (66,654 ) — — — (66,654 ) Proceeds from dispositions of property and equipment 6,953 — — — 6,953 Proceeds from vendor performance obligations 13,600 — — — 13,600 Net change in accounts with affiliates (37,282 ) (302 ) — 37,584 — Net cash flows used in investing activities of continuing operations (83,383 ) (302 ) — 37,584 (46,101 ) Net cash flows used in investing activities of discontinued operations (153 ) — — — (153 ) Cash used in investing activities (83,536 ) (302 ) — 37,584 (46,254 ) FINANCING ACTIVITIES: Repayment of long term note payable (2,500 ) — (10,547 ) — (13,047 ) Distributions paid to minority interests — — (3 ) — (3 ) Taxes paid on settlement of vested share awards — — (308 ) — (308 ) Net change in accounts with affiliates — 10,342 8,603 (18,945 ) — Capital contributions — 926 (926 ) — — Exercise of stock options and purchases from employee stock plans — — 668 — 668 Excess income tax benefit from share-based compensation — — 154 — 154 Borrowings under revolving loans — — 227,000 — 227,000 Repayments of revolving loans — — (192,000 ) — (192,000 ) Net cash flows provided by (used in) financing activities of continuing operations (2,500 ) 11,268 32,641 (18,945 ) 22,464 Net cash flows provided by financing activities of discontinued operations 12,016 6,623 — (18,639 ) — Cash provided by financing activities 9,516 17,891 32,641 (37,584 ) 22,464 Effect of foreign currency exchange rates on cash and cash equivalents — (135 ) — — (135 ) Net increase in cash and cash equivalents 47,667 3,231 — — 50,898 Cash and cash equivalents at beginning of period 24,272 168 — — 24,440 Cash and cash equivalents at end of period $ 71,939 $ 3,399 $ — $ — $ 75,338

Schedule II-Valuation And Quali

Schedule II-Valuation And Qualify Accounts	12 Months Ended
	Dec. 31, 2015
Valuation And Qualifying Accounts [Abstract]
Schedule II-Valuation And Qualifying Accounts	Additions Beginning Balance Charged to costs and expenses Charged to other accounts Deductions Ending balance Description Year ended December 31, 2013 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ 1,051 $ 478 $ — $ — $ 1,529 Valuation allowance for deferred tax assets 3,352 (847 ) 2,505 Total $ 4,403 $ (369 ) $ — $ — $ 4,034 Year ended December 31, 2014 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ 1,529 $ 100 $ — $ (1,051 ) $ 578 Valuation allowance for deferred tax assets 2,505 4,074 6,579 Total $ 4,034 $ 4,174 $ — $ (1,051 ) $ 7,157 Year ended December 31, 2015 Allowances deducted from assets to which they apply: Allowances for doubtful accounts $ 578 $ 176 $ — $ — $ 754 Valuation allowance for deferred tax assets 6,579 270 (748 ) 6,101 Total $ 7,157 $ 446 $ — $ (748 ) $ 6,855

Subsidiary Guarantors (Tables)

Subsidiary Guarantors (Tables)	12 Months Ended
	Dec. 31, 2015
Condensed Financial Information Of Parent Company Only Disclosure [Abstract]
Condensed Cash Flow Statement	ERROR: Could not retrieve Word content for note block Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals OPERATING ACTIVITIES: Net cash flows provided by operating activities of continuing operations $ 63,276 $ 999 $ 2,879 $ — $ 67,154 Net cash flows used in operating activities of discontinued operations (17,328 ) (1,024 ) — — (18,352 ) Cash provided by (used in) operating activities 45,948 (25 ) 2,879 — 48,802 INVESTING ACTIVITIES: Purchases of property and equipment (91,910 ) — — — (91,910 ) Proceeds from dispositions of property and equipment 68 — — — 68 Payments for acquisitions of businesses (2,048 ) — (25,000 ) — (27,048 ) Proceeds from vendor performance obligations (3,100 ) — — — (3,100 ) Net change in accounts with affiliates 68,187 — — (68,187 ) — Net cash flows used in investing activities of continuing operations (28,803 ) — (25,000 ) (68,187 ) (121,990 ) Net cash flows provided by investing activities of discontinued operations 5,275 — — — 5,275 Cash used in investing activities (23,528 ) — (25,000 ) (68,187 ) (116,715 ) FINANCING ACTIVITIES: Proceeds from term loan facility — — 47,360 — 47,360 Repayments of term loan facility — — (417 ) — (417 ) Proceeds from issuance of 7 3/8% senior notes — — 24,880 — 24,880 Deferred financing fees — — (2,532 ) — (2,532 ) Taxes paid on settlement of vested share awards — — (497 ) — (497 ) Purchase of noncontrolling interest — — (205 ) — (205 ) Net change in accounts with affiliates — (2,547 ) (65,640 ) 68,187 — Intercompany dividends (52,400 ) — 52,400 — — Repayments of equipment debt (235 ) — — — (235 ) Exercise of stock options and purchases from employee stock plans — — 1,568 — 1,568 Excess income tax benefit from share-based compensation — — 206 — 206 Borrowings under revolving loans — — 236,500 — 236,500 Repayments of revolving loans — — (271,500 ) — (271,500 ) Cash provided by (used in) financing activities (52,635 ) (2,547 ) 22,123 68,187 35,128 Effect of foreign currency exchange rates on cash and cash equivalents — (164 ) — — (164 ) Net increase (decrease) in cash and cash equivalents (30,215 ) (2,736 ) 2 — (32,949 ) Cash and cash equivalents at beginning of period 71,939 3,399 — — 75,338 Cash and cash equivalents at end of period $ 41,724 $ 663 $ 2 $ — $ 42,389 GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS FOR THE YEAR ENDED DECEMBER 31, 2013 (In thousands) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Corporation Eliminations Consolidated Totals OPERATING ACTIVITIES: Net cash flows provided by (used in) operating activities of continuing operations $ 126,736 $ (7,748 ) $ (32,641 ) $ — $ 86,347 Net cash flows used in operating activities of discontinued operations (5,049 ) (6,475 ) — — (11,524 ) Cash provided by (used in) operating activities 121,687 (14,223 ) (32,641 ) — 74,823 INVESTING ACTIVITIES: Purchases of property and equipment (66,654 ) — — — (66,654 ) Proceeds from dispositions of property and equipment 6,953 — — — 6,953 Proceeds from vendor performance obligations 13,600 — — — 13,600 Net change in accounts with affiliates (37,282 ) (302 ) — 37,584 — Net cash flows used in investing activities of continuing operations (83,383 ) (302 ) — 37,584 (46,101 ) Net cash flows used in investing activities of discontinued operations (153 ) — — — (153 ) Cash used in investing activities (83,536 ) (302 ) — 37,584 (46,254 ) FINANCING ACTIVITIES: Repayment of long term note payable (2,500 ) — (10,547 ) — (13,047 ) Distributions paid to minority interests — — (3 ) — (3 ) Taxes paid on settlement of vested share awards — — (308 ) — (308 ) Net change in accounts with affiliates — 10,342 8,603 (18,945 ) — Capital contributions — 926 (926 ) — — Exercise of stock options and purchases from employee stock plans — — 668 — 668 Excess income tax benefit from share-based compensation — — 154 — 154 Borrowings under revolving loans — — 227,000 — 227,000 Repayments of revolving loans — — (192,000 ) — (192,000 ) Net cash flows provided by (used in) financing activities of continuing operations (2,500 ) 11,268 32,641 (18,945 ) 22,464 Net cash flows provided by financing activities of discontinued operations 12,016 6,623 — (18,639 ) — Cash provided by financing activities 9,516 17,891 32,641 (37,584 ) 22,464 Effect of foreign currency exchange rates on cash and cash equivalents — (135 ) — — (135 ) Net increase in cash and cash equivalents 47,667 3,231 — — 50,898 Cash and cash equivalents at beginning of period 24,272 168 — — 24,440 Cash and cash equivalents at end of period $ 71,939 $ 3,399 $ — $ — $ 75,338
Condensed Consolidating of Balance Sheet	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES CONDENSED CONSOLIDATING BALANCE SHEET AS OF DECEMBER 31, 2015 (In thousands) ASSETS Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated CURRENT ASSETS: Cash and cash equivalents $ 12,035 $ 2,147 $ 2 $ — $ 14,184 Accounts receivable — net 129,978 799 — — 130,777 Contract revenues in excess of billings 79,477 1,718 — — 81,195 Inventories 35,963 — — — 35,963 Prepaid expenses 7,924 — — — 7,924 Other current assets 58,995 218 477 — 59,690 Total current assets 324,372 4,882 479 — 329,733 PROPERTY AND EQUIPMENT—Net 430,192 18 — — 430,210 GOODWILL 83,576 — — — 83,576 OTHER INTANGIBLE ASSETS—Net 2,428 — — — 2,428 INVENTORIES — Noncurrent 41,646 — — — 41,646 INVESTMENTS IN JOINT VENTURES 3,761 — — — 3,761 RECEIVABLES FROM AFFILIATES 18,326 6,009 70,738 (95,073 ) — INVESTMENTS IN SUBSIDIARIES 3,706 — 621,984 (625,690 ) — OTHER 6,702 3 3,566 — 10,271 TOTAL $ 914,709 $ 10,912 $ 696,767 $ (720,763 ) $ 901,625 LIABILITIES AND EQUITY CURRENT LIABILITIES: Accounts payable $ 118,619 $ 227 $ — $ — $ 118,846 Accrued expenses 62,861 509 8,907 — 72,277 Billings in excess of contract revenues 6,964 97 — — 7,061 Current portion of long term debt 1,424 — 6,082 — 7,506 Total current liabilities 189,868 833 14,989 — 205,690 7 3/8% SENIOR NOTES — — 274,909 — 274,909 REVOLVING CREDIT FACILITY — — 20,000 — 20,000 NOTE PAYABLE 323 — 54,059 — 54,382 DEFERRED INCOME TAXES (783 ) — 74,789 — 74,006 PAYABLES TO AFFILIATES 85,859 3,505 5,709 (95,073 ) — OTHER 20,326 — 139 — 20,465 Total liabilities 295,593 4,338 444,594 (95,073 ) 649,452 TOTAL EQUITY 619,116 6,574 252,173 (625,690 ) 252,173 TOTAL $ 914,709 $ 10,912 $ 696,767 $ (720,763 ) $ 901,625 ASSETS Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated CURRENT ASSETS: Cash and cash equivalents $ 41,724 $ 663 $ 2 $ — $ 42,389 Accounts receivable — net 115,739 355 — (2,906 ) 113,188 Receivables from affiliates 152,822 3,673 55,805 (212,300 ) — Contract revenues in excess of billings 78,631 4,236 — (310 ) 82,557 Inventories 34,735 — — — 34,735 Prepaid expenses 4,708 — — — 4,708 Other current assets 49,619 431 14,617 — 64,667 Total current assets 477,978 9,358 70,424 (215,516 ) 342,244 PROPERTY AND EQUIPMENT—Net 399,421 24 — — 399,445 GOODWILL 86,326 — — — 86,326 OTHER INTANGIBLE ASSETS—Net 8,963 — — — 8,963 INVENTORIES — Noncurrent 36,262 — — — 36,262 INVESTMENTS IN JOINT VENTURES 7,889 — — — 7,889 INVESTMENTS IN SUBSIDIARIES 3,757 — 619,220 (622,977 ) — OTHER 7,135 3 4,967 — 12,105 TOTAL $ 1,027,731 $ 9,385 $ 694,611 $ (838,493 ) $ 893,234 LIABILITIES AND EQUITY CURRENT LIABILITIES: Accounts payable $ 121,282 $ 1,389 $ 516 $ (3,216 ) $ 119,971 Payables to affiliates 196,829 403 15,068 (212,300 ) — Accrued expenses 60,415 659 8,967 — 70,041 Billings in excess of contract revenues 4,639 — — — 4,639 Current portion of long term debt 859 — 5,000 — 5,859 Total current liabilities 384,024 2,451 29,551 (215,516 ) 200,510 7 3/8% SENIOR NOTES — — 274,880 — 274,880 NOTE PAYABLE 7,553 — 41,944 — 49,497 DEFERRED INCOME TAXES 172 — 91,835 — 92,007 OTHER 19,939 — 438 — 20,377 Total liabilities 411,688 2,451 438,648 (215,516 ) 637,271 TOTAL EQUITY 616,043 6,934 255,963 (622,977 ) 255,963 TOTAL $ 1,027,731 $ 9,385 $ 694,611 $ (838,493 ) $ 893,234
Schedule Of Condensed Consolidating Operations And Comprehensive Income	Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals Contract revenues $ 845,889 $ 13,698 $ — $ (2,709 ) $ 856,878 Costs of contract revenues (750,509 ) (13,155 ) — 2,709 (760,955 ) Gross profit 95,380 543 — — 95,923 OPERATING EXPENSES: General and administrative expenses 71,069 — — — 71,069 Impairment of goodwill 2,750 — — — 2,750 Gain on sale of assets—net (855 ) — — — (855 ) Operating income 22,416 543 — — 22,959 Interest income (expense)—net (526 ) — (23,839 ) — (24,365 ) Equity in earnings of subsidiaries 8 — 16,282 (16,290 ) — Equity in loss of joint ventures (6,051 ) — — — (6,051 ) Other expense (1,222 ) (7 ) — — (1,229 ) Income (loss) before income taxes 14,625 536 (7,557 ) (16,290 ) (8,686 ) Income tax (provision) benefit 1,505 (376 ) 1,368 — 2,497 Net income (loss) $ 16,130 $ 160 $ (6,189 ) $ (16,290 ) $ (6,189 ) Comprehensive income (loss) $ 16,130 $ (1,089 ) $ (7,438 ) $ (15,041 ) $ (7,438 ) Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Eliminations Consolidated Totals Contract revenues $ 799,579 $ 26,282 $ — $ (19,030 ) $ 806,831 Costs of contract revenues (707,474 ) (25,891 ) — 19,030 (714,335 ) Gross profit 92,105 391 — — 92,496 OPERATING EXPENSES: General and administrative expenses 67,905 6 — — 67,911 Loss on sale of assets—net 732 — — — 732 Operating income 23,468 385 — — 23,853 Interest income (expense)—net 61 (261 ) (19,767 ) — (19,967 ) Equity in earnings of subsidiaries 20 — 10,373 (10,393 ) — Equity in earnings of joint ventures 2,895 — — — 2,895 Gain on bargain purchase acquisition 2,197 — — — 2,197 Other income 203 7 — — 210 Income (loss) from continuing operations before income taxes 28,844 131 (9,394 ) (10,393 ) 9,188 Income tax (provision) benefit (18,173 ) (409 ) 30,112 — 11,530 Income (loss) from continuing operations 10,671 (278 ) 20,718 (10,393 ) 20,718 Loss from discontinued operations, net of income taxes (10,423 ) (1,343 ) (10,423 ) 11,766 (10,423 ) Net income (loss) $ 248 $ (1,621 ) $ 10,295 $ 1,373 $ 10,295 Comprehensive income (loss) $ 49 $ (1,683 ) $ 10,034 $ 1,634 $ 10,034 Subsidiary Guarantors Non-Guarantor Subsidiaries GLDD Corporation Eliminations Consolidated Totals Contract revenues $ 718,041 $ 24,932 $ — $ (11,555 ) $ 731,418 Costs of contract revenues (614,908 ) (27,770 ) — 11,555 (631,123 ) Gross profit 103,133 (2,838 ) — — 100,295 OPERATING EXPENSES: General and administrative expenses 68,029 10 — — 68,039 Proceeds from loss of use claim (13,372 ) — — — (13,372 ) (Gain) loss on sale of assets—net (5,775 ) — 2 — (5,773 ) Operating income (loss) 54,251 (2,848 ) (2 ) — 51,401 Interest income (expense)—net (136 ) (256 ) (21,549 ) — (21,941 ) Equity in earnings of subsidiaries 212 — 59,477 (59,689 ) — Equity in earnings of joint ventures 1,208 — — — 1,208 Other expense (3 ) (348 ) — — (351 ) Income (loss) from continuing operations before income taxes 55,532 (3,452 ) 37,926 (59,689 ) 30,317 Income tax (provision) benefit 293 4 (10,757 ) — (10,460 ) Income (loss) from continuing operations 55,825 (3,448 ) 27,169 (59,689 ) 19,857 Loss from discontinued operations, net of income taxes (55,106 ) (1,448 ) (62,162 ) 63,866 (54,850 ) Net income (loss) 719 (4,896 ) (34,993 ) 4,177 (34,993 ) Net loss attributable to noncontrolling interests — — 632 — 632 Net income (loss) attributable to Great Lakes Dredge & Dock Corporation $ 719 $ (4,896 ) $ (34,361 ) $ 4,177 $ (34,361 ) Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation $ 1,023 $ (5,293 ) $ (34,454 ) $ 4,270 $ (34,454 )

Nature Of Business And Summar30

Nature Of Business And Summary Of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2015
Organization Consolidation And Presentation Of Financial Statements [Abstract]
Estimated Useful Lives By Class Of Assets	The estimated useful lives by class of assets are: Class Useful Life (years) Buildings and improvements 10 Furniture and fixtures 5-10 Vehicles, dozers, and other light operating equipment and systems 3-5 Heavy operating equipment (dredges and barges) 10-30

Earnings per share (Tables)

Earnings per share (Tables)	12 Months Ended
	Dec. 31, 2015
Earnings Per Share [Abstract]
Computations For Basic And Diluted Earnings Per Share	The computations for basic and diluted earnings per share for the years ended December 31, 2015, 2014 and 2013 are as follows: (shares in thousands) 2015 2014 2013 Income (loss) from continuing operations $ (6,189 ) $ 20,718 $ 19,857 Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation — (10,423 ) (54,218 ) Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ (6,189 ) $ 10,295 $ (34,361 ) Weighted-average common shares outstanding — basic 60,410 59,938 59,495 Effect of stock options and restricted stock units — 584 606 Weighted-average common shares outstanding — diluted 60,410 60,522 60,101 Earnings (loss) per share from continuing operations — basic $ (0.10 ) $ 0.35 $ 0.33 Earnings (loss) per share from continuing operations — diluted $ (0.10 ) $ 0.34 $ 0.33

Accounts Receivable And Contr32

Accounts Receivable And Contracts In Progress (Tables)	12 Months Ended
	Dec. 31, 2015
Receivables [Abstract]
Schedule Of Accounts Receivable	Accounts receivable at December 31, 2015 and 2014 are as follows: 2015 2014 Completed contracts $ 37,111 $ 15,342 Contracts in progress 70,787 72,459 Retainage 27,203 27,371 135,101 115,172 Allowance for doubtful accounts (754 ) (578 ) Total accounts receivable—net $ 134,347 $ 114,594 Current portion of accounts receivable—net $ 130,777 $ 113,188 Long-term accounts receivable and retainage 3,570 1,406 Total accounts receivable—net $ 134,347 $ 114,594
Components Of Contracts In Progress	The components of contracts in progress at December 31, 2015 and 2014 are as follows: 2015 2014 Costs and earnings in excess of billings: Costs and earnings for contracts in progress $ 230,159 $ 833,368 Amounts billed (176,283 ) (759,877 ) Costs and earnings in excess of billings for contracts in progress 53,876 73,491 Costs and earnings in excess of billings for completed contracts 27,319 9,066 Total contract revenues in excess of billings $ 81,195 $ 82,557 Billings in excess of costs and earnings: Amounts billed $ (207,550 ) $ (181,698 ) Costs and earnings for contracts in progress 200,489 177,059 Total billings in excess of contract revenues $ (7,061 ) $ (4,639 )

Property And Equipment (Tables)

Property And Equipment (Tables)	12 Months Ended
	Dec. 31, 2015
Property Plant And Equipment [Abstract]
Schedule Of Property Plant And Equipment	2015 2014 Land $ 9,864 $ 9,220 Buildings and improvements 5,896 5,729 Furniture and fixtures 10,587 8,863 Operating equipment 783,732 698,977 Total property and equipment 810,079 722,789 Accumulated depreciation (379,869 ) (323,344 ) Property and equipment — net $ 430,210 $ 399,445

Goodwill And Other Intangible34

Goodwill And Other Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2015
Goodwill And Intangible Assets Disclosure [Abstract]
Schedule of Goodwill	Dredgin g Environmental & Remediatio n Total Balance – January 1, 2014 $ 76,576 $ 2,750 $ 79,326 Acquisition of Magnus Pacific — 7,000 7,000 Balance – December 31, 2014 76,576 9,750 86,326 Impairment of goodwill — (2,750 ) (2,750 ) Balance – December 31, 2015 $ 76,576 $ 7,000 $ 83,576
Schedule of the Net Book Value Of Identifiable Intangible Assets	As of December 31, 2015 Cost Accumulated Amortization Net Non-compete agreements $ 3,085 $ 1,625 $ 1,460 Trade names 1,037 873 164 Other 1,306 502 804 $ 5,428 $ 3,000 $ 2,428 As of December 31, 2014 Non-compete agreements $ 3,085 $ 940 $ 2,145 Customer relationships 51 34 17 Acquired backlog 6,278 1,395 4,883 Trade names 1,037 185 852 Other 1,306 240 1,066 $ 11,757 $ 2,794 $ 8,963

Accrued Expenses (Tables)

Accrued Expenses (Tables)	12 Months Ended
	Dec. 31, 2015
Payables And Accruals [Abstract]
Accrued Expenses	Accrued expenses at December 31, 2015 and 2014 are as follows: 2015 2014 Insurance $ 16,291 $ 16,778 Accumulated deficit in joint venture 15,408 10,383 Payroll and employee benefits 13,317 8,808 Interest 8,743 8,270 Fuel hedge contracts 4,388 3,029 Income and other taxes 3,726 5,857 Percentage of completion adjustment 2,837 1,870 Other 7,567 15,046 Total accrued expenses $ 72,277 $ 70,041

Long-Term Debt (Tables)

Long-Term Debt (Tables)	12 Months Ended
	Dec. 31, 2015
Debt Disclosure [Abstract]
Schedule Of Long-Term Debt	Long-term debt at December 31, 2015 and 2014 is as follows: 2015 2014 Revolving credit facility $ 20,000 $ — Equipment notes payable 3,972 2,857 Notes payable 60,595 54,620 7.375% senior notes 274,909 274,880 Subtotal 359,476 332,357 Current portion of equipment note payable (1,293 ) (736 ) Current portion of note payable (6,213 ) (5,123 ) Capital leases (included in other long term liabilities) (2,679 ) (2,121 ) Total $ 349,291 $ 324,377
Maturities Of Long-Term Debt	The scheduled principal payments through the maturity date of the Company’s long-term debt, excluding equipment notes and capital leases, at December 31, 2015, are as follows: Years Ending December 31 2016 $ 21,498 2017 16,145 2018 11,421 2019 295,461 2020 1,815 Thereafter 8,800 Total $ 355,140

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2015
Fair Value Disclosures [Abstract]
Schedule Of Fair Values Of Financial Instruments And Nonfinancial Assets And Liabilities Measured At The Reporting Date	The fair values of these financial instruments are summarized as follows: Fair Value Measurements at Reporting Date Using Description At December 31, 2015 Quoted Active Markets for Identical Assets (Level 1) Significant Observable Inputs (Level 2) Significant Unobservable (Level 3) Fuel hedge contracts $ 4,388 $ — $ 4,388 $ — Fair Value Measurements at Reporting Date Using Description At December 31, 2014 Quoted Prices in Active Markets for Identical Assets (Level 1) Significant Other Observable Inputs (Level 2) Significant Unobservable Inputs (Level 3) Fuel hedge contracts $ 3,029 $ — $ 3,029 $ —
Schedule Fair Value Measurements Balance Sheet Location	The fair value of the fuel hedge contracts outstanding as of December 31, 2015 and 2014 is as follows: Balance Sheet Location Fair Value at December 31, 2015 2014 Liability derivatives: Derivatives not designated as hedges Fuel hedge contracts Accrued expenses $ 4,388 $ 3,029
Fair Value, Assets Measured On Recurring Basis, Unobservable Input Reconciliation	The fair value of goodwill was determined using quantitative models that contained significant unobservable inputs and accordingly is a Level 3 fair value measurement. See Note 6. Fair 2015 Goodwill Balance at January 1, $ 86,326 Impairment of goodwill (2,750 ) Balance at December 31, 2015 $ 83,576
Changes In Components Of Accumulated Other Comprehensive Loss	Changes in the components of the accumulated balances of other comprehensive income are as follows: 2015 2014 2013 Cumulative translation adjustments—net of tax $ (1,249 ) $ (62 ) $ (397 ) Derivatives: Reclassification of derivative losses (gains) to earnings—net of tax — (332 ) 270 Change in fair value of derivatives—net of tax — 133 34 Net unrealized (gain) loss on derivatives—net of tax — (199 ) 304 Total other comprehensive loss $ (1,249 ) $ (261 ) $ (93 )
Adjustments Reclassified From Accumulated Other Comprehensive Loss To Earnings	Adjustments reclassified from accumulated balances of other comprehensive income to earnings are as follows: Statement of Operations Location 2014 2013 Derivatives: Fuel hedge contracts Costs of contract revenues $ (286 ) $ 450 Income tax benefit 46 180 $ (332 ) $ 270

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2015
Income Tax Disclosure [Abstract]
Schedule Of Components Of Income Tax Expense Benefit From Continuing And Discontinued Operations	2015 2014 2013 Income tax (provision) benefit from continuing operations $ 2,497 $ 11,530 $ (10,460 ) Income tax benefit from discontinued operations — 8,744 19,116 Income tax benefit $ 2,497 $ 20,274 $ 8,656
Pre-Tax Income From Domestic And Foreign Operations	2015 2014 2013 Domestic operations $ (35,996 ) $ (20,823 ) $ 23,716 Foreign operations 27,310 30,011 6,601 Total pre-tax income (loss) $ (8,686 ) $ 9,188 $ 30,317
Provision For Income Taxes	2015 2014 2013 Federal: Current $ — $ (174 ) $ 8,384 Deferred (2,355 ) (9,531 ) 2,107 State: Current 115 277 439 Deferred (673 ) (3,577 ) (326 ) Foreign: Current 416 1,475 1,831 Deferred — — (1,975 ) Total $ (2,497 ) $ (11,530 ) $ 10,460
Income Tax Provision (Benefit) Reconciliation	2015 2014 2013 Tax provision at statutory U.S. federal income tax rate $ (3,040 ) $ 3,214 $ 10,611 State income tax — net of federal income tax benefit (676 ) (2,726 ) 500 Worthless stock deduction — (9,631 ) — Charitable contributions (469 ) (1,764 ) — Adjustment to deferred tax depreciation 1,135 (1,670 ) — Change in deferred state tax rate — (811 ) — Research and development tax credits (286 ) (691 ) — Purchase price adjustment 393 (393 ) — Foreign income tax provision (benefit) — — 238 Changes in unrecognized tax benefits (186 ) 127 (196 ) Changes in valuation allowance 270 2,246 (500 ) Other 362 569 (193 ) Income tax provision (benefit) $ (2,497 ) $ (11,530 ) $ 10,460
Reconciliation Of Unrecognized Tax Benefits	2015 2014 2013 Unrecognized tax benefits — January 1 $ 442 $ 253 $ 471 Gross increases — tax positions in prior period — — — Gross increases — current period tax positions — 270 42 Gross decreases — expirations — (65 ) (201 ) Gross decreases — tax positions in prior period (285 ) (16 ) (59 ) Unrecognized tax benefits — December 31, $ 157 $ 442 $ 253
Deferred Tax Assets (Liabilities)	2015 2014 Deferred tax assets: Accrued liabilities $ 17,841 $ 13,288 Federal NOLs 24,687 19,365 Foreign NOLs 3,586 4,334 State NOLs 6,008 4,752 Tax credit carryforwards 5,374 4,651 Charitable contribution 2,233 1,764 Valuation allowance (6,102 ) (6,579 ) Total deferred tax assets 53,627 41,575 Deferred tax liabilities: Depreciation and amortization (126,174 ) (117,286 ) Other liabilities (1,459 ) (1,811 ) Total deferred tax liabilities (127,633 ) (119,097 ) Net deferred tax liabilities $ (74,006 ) $ (77,522 ) As reported in the balance sheet: Net current deferred tax assets (included in other current assets) $ — $ 14,485 Net noncurrent deferred tax liabilities (74,006 ) (92,007 ) Net deferred tax liabilities $ (74,006 ) $ (77,522 )

Share-Based Compensation (Table

Share-Based Compensation (Tables)	12 Months Ended
	Dec. 31, 2015
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Option Pricing Assumptions	The weighted-average grant-date fair value of options granted during the years ended December 31, 2014 and 2013 was $4.23 and $4.06 respectively. The fair value of each option was estimated using the following assumptions: 2014 2013 Expected volatility 53.9 % 58.2 % Expected dividends 0.0 % 0.0 % Expected term (in years) 7.0 6.0 Risk free rate 1.9 % 1.0 %
Summary Of Stock Option Activity	A summary of stock option activity under the Incentive Plan as of December 31, 2015, and changes during the year ended December 31, 2015, is presented below: Options Shares Weighted Exercise Price Weighted-Average Remaining Contract Term (yrs) Aggregate Intrinsic Value ($000's) Outstanding as of January 1, 2015 1,889 $ 6.31 Granted — — Exercised (86 ) 5.35 Forfeited or Expired (77 ) 7.14 Outstanding as of December 31, 2015 1,726 $ 6.32 Vested at December 31, 2015 1,447 $ 6.07 5.3 $ 17 Vested or expected to vest at December 31, 2015 1,724 $ 6.32 5.8 $ 17
Summary of Non-Vested Restricted Stock Units	A summary of the status of the Company’s non-vested RSUs as of December 31, 2015, and changes during the year ended December 31, 2015, is presented below: Nonvested Restricted Stock Units Shares Weighted-Average Grant-Date Fair Value Outstanding as of January 1, 2015 2,063 $ 6.91 Granted 784 5.65 Vested (160 ) 6.42 Forfeited (491 ) 6.79 Outstanding as of December 31, 2015 2,196 $ 6.57 Expected to vest at December 31, 2015 1,140 $ 6.37

Commitments And Contingencies (

Commitments And Contingencies (Tables)	12 Months Ended
	Dec. 31, 2015
Commitments And Contingencies Disclosure [Abstract]
Future Minimum Operating Lease Payments	Future minimum operating lease payments at December 31, 2015, are as follows: 2016 $ 22,516 2017 20,800 2018 13,034 2019 8,802 2020 6,246 Thereafter 10,866 Total minimum operating lease payments $ 82,264

Investment (Tables)

Investment (Tables)	12 Months Ended
	Dec. 31, 2015
Amboy Aggregates [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ 139 $ 13,784 $ 24,399 Gross profit (1,363 ) (118 ) 4,142 Income (loss) from continuing operations (3,152 ) 11,326 2,329 Net income (loss) (3,152 ) 9,527 3,998
Lower Main Street Development [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ — $ 180 $ 180 Gross profit — 180 180 Net income 28 14,803 175
TerraSea Environmental Solutions [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investments	The Company accounts for this investment under the equity method. The following is summarized financial information for this entity: 2015 2014 2013 Revenue $ 6,960 $ 11,278 $ 7,368 Gross profit (3,800 ) (19,153 ) (956 ) Net income (loss) (3,800 ) (19,856 ) (956 )

Business Combinations And Dispo

Business Combinations And Dispositions (Tables)	12 Months Ended
	Dec. 31, 2015
Business Combinations [Abstract]
Unaudited Pro Forma Consolidated Financial Information	The results of the businesses have been reported in discontinued operations as follows: 2014 2013 Revenue $ 14,803 $ 39,550 Loss before income taxes from discontinued operations $ (19,167 ) $ (55,530 ) Loss on disposal of assets held for sale — (18,436 ) Income tax benefit 8,744 19,116 Loss from discontinued operations, net of income taxes $ (10,423 ) $ (54,850 )
Schedule Of Discontinued Operations	The unaudited pro forma consolidated financial information are provided for illustrative purposes only and do not purport to present what the actual results of operations would have been had the transaction actually occurred on the date indicated, nor does it purport to represent results of operations for any future period. The information does not reflect any cost savings or benefits that may be obtained through synergies among the operations of the Company. 2014 2013 (Unaudited) Revenue as reported $ 806,831 $ 731,418 Revenue of purchased businesses for the period prior to the acquisition 106,723 87,943 Pro forma revenue $ 913,554 $ 819,361 Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ 10,295 $ (34,361 ) Net income of Magnus including net income prior to acquisition and pro forma acquisition accounting adjustments 6,328 1,069 Pro forma net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation $ 16,623 $ (33,292 )

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2015
Segment Reporting [Abstract]
Segment Reporting By Segment	2015 2014 2013 Dredging: Contract revenues $ 681,255 $ 697,711 $ 642,602 Operating income 64,073 41,620 54,683 Depreciation and amortization 50,556 43,620 44,118 Total assets 875,797 815,683 821,253 Property and equipment—net 397,468 366,027 330,689 Goodwill 76,576 76,576 76,576 Investment in joint ventures 1 2,114 8,256 Capital expenditures 82,000 79,186 57,902 Environmental & remediation: Contract revenues 181,710 114,412 94,840 Operating loss (41,114 ) (17,767 ) (3,282 ) Depreciation and amortization 14,029 6,509 2,504 Total assets 127,907 134,324 98,505 Property and equipment—net 32,742 33,418 14,931 Goodwill 7,000 9,750 2,750 Investment in joint ventures 3,760 5,775 — Capital expenditures 7,279 12,892 4,100 Intersegment: Contract revenues (6,087 ) (5,292 ) (6,024 ) Total assets (102,080 ) (56,773 ) (67,113 ) Total: Contract revenues 856,878 806,831 731,418 Operating income 22,959 23,853 51,401 Depreciation and amortization 64,585 50,129 46,622 Total assets 901,625 893,234 852,645 Property and equipment—net 430,210 399,445 345,620 Goodwill 83,576 86,326 79,326 Investment in joint ventures 3,761 7,889 8,256 Capital expenditures 89,279 92,078 62,002
Revenue Related to Dredging Projects By Type Of Work	2015 2014 2013 Capital dredging — U.S. $ 207,058 $ 195,635 $ 153,781 Capital dredging — foreign 139,945 155,000 138,436 Coastal protection dredging 184,060 194,219 228,868 Maintenance dredging 120,055 123,923 90,833 Rivers & lakes 30,137 28,934 30,684 Total dredging $ 681,255 $ 697,711 $ 642,602
Revenues And Gross Profit From Foreign Project Operations	2015 2014 2013 Contract revenues $ 139,945 $ 155,000 $ 138,436 Costs of contract revenues (105,951 ) (118,682 ) (117,029 ) Gross profit $ 33,994 $ 36,318 $ 21,407

Nature Of Business And Summar44

Nature Of Business And Summary Of Significant Accounting Policies (Narrative) (Details) - segment	12 Months Ended
	Dec. 31, 2015	Jan. 02, 2009
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of operating Segments	3
Number of reportable segments	2
Terra and Magnus [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Number of reportable segments	1
Yankee Environmental Services, LLC [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Acquired membership interest		65.00%
Minimum [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Average equipment-related costs of total costs of contract revenue	20.00%
Maximum [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]
Average equipment-related costs of total costs of contract revenue	22.00%

Nature Of Business And Summar45

Nature Of Business And Summary Of Significant Accounting Policies (Estimated Useful Lives By Class Of Assets) (Details)	12 Months Ended
	Dec. 31, 2014
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Furniture and Fixtures [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Furniture and Fixtures [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Vehicles, Dozers, And Other Light Operating Equipment And Systems [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	3 years
Vehicles, Dozers, And Other Light Operating Equipment And Systems [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	5 years
Heavy Operating Equipment (Dredges And Barges) [Member] | Minimum [Member]
Property, Plant and Equipment [Line Items]
Useful life	10 years
Heavy Operating Equipment (Dredges And Barges) [Member] | Maximum [Member]
Property, Plant and Equipment [Line Items]
Useful life	30 years

Earnings per share (Narrative)

Earnings per share (Narrative) (Detail) - shares shares in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Earnings Per Share [Abstract]
Shares excluded from computation of diluted earnings per share	1,179	540
Securities excluded from computation of earnings per share amount due to loss	431

Earnings Per Share (Details)

Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Earnings Per Share [Abstract]
Income (loss) from continuing operations	$ (6,189)	$ 20,718	$ 19,857
Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation		(10,423)	(54,218)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION	$ (6,189)	$ 10,295	$ (34,361)
Weighted-average common shares outstanding — basic	60,410	59,938	59,495
Effect of stock options and restricted stock units		584	606
Weighted-average common shares outstanding — diluted	60,410	60,522	60,101
Earnings (loss) per share from continuing operations — basic	$ (0.10)	$ 0.35	$ 0.33
Earnings (loss) per share from continuing operations — diluted	$ (0.10)	$ 0.34	$ 0.33

Restricted And Escrowed Cash (D

Restricted And Escrowed Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Cash And Cash Equivalents [Line Items]
OTHER	$ 10,271	$ 12,105
Escrow Account [Member]
Cash And Cash Equivalents [Line Items]
OTHER	1,500	1,500
Assets held for sale	$ 2,242	$ 2,314

Accounts Receivable And Contr49

Accounts Receivable And Contracts In Progress (Schedule Of Accounts Receivable) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable [Line Items]
Retainage	$ 27,203	$ 27,371
Accounts receivable, gross	135,101	115,172
Allowance for doubtful accounts	(754)	(578)
Total accounts receivable—net	134,347	114,594
Current portion of accounts receivable—net	130,777	113,188
Long-term accounts receivable and retainage	3,570	1,406
Completed Contracts [Member]
Accounts Notes And Loans Receivable [Line Items]
contracts	37,111	15,342
Contracts In Progress [Member]
Accounts Notes And Loans Receivable [Line Items]
contracts	$ 70,787	$ 72,459

Accounts Receivable And Contr50

Accounts Receivable And Contracts In Progress (Components Of Contracts In Progress) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings in excess of billings for contracts in progress	$ 53,876	$ 73,491
Costs and earnings in excess of billings for completed contracts	27,319	9,066
Total contract revenues in excess of billings	81,195	82,557
Total billings in excess of contract revenues	(7,061)	(4,639)
Costs And Earnings In Excess Of Billings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	230,159	833,368
Amounts billed	(176,283)	(759,877)
Billings In Excess Of Costs And Earnings [Member]
Accounts Notes And Loans Receivable [Line Items]
Costs and earnings for contracts in progress	200,489	177,059
Amounts billed	$ (207,550)	$ (181,698)

Accounts Receivable And Contr51

Accounts Receivable And Contracts In Progress (Narrative) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Receivables [Abstract]
Costs in excess of billings	$ 17,875

Property And Equipment (Details

Property And Equipment (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 810,079	$ 722,789
Accumulated depreciation	(379,869)	(323,344)
Property and equipment — net	430,210	399,445	$ 345,620
Land [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	9,864	9,220
Building and Improvements [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	5,896	5,729
Furniture and Fixtures [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	10,587	8,863
Operating Equipment [Member]
Property, Plant and Equipment [Line Items]
Total property and equipment	$ 783,732	$ 698,977

Property And Equipment (Narrati

Property And Equipment (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Property Plant And Equipment [Abstract]
Depreciation	$ 58,050	$ 48,569	$ 45,531

Goodwill And Other Intangible54

Goodwill And Other Intangible Assets (Narrative) (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Jun. 30, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Impairment of goodwill		$ 2,750
Weighted average amortization period			3 years 2 months 16 days
Amortization expense		6,535	$ 1,560	$ 1,091
2,015		920
2,016		920
2,017		454
2,018		134
2,019		$ 134
Terra Contracting Services [Member]
Impairment of goodwill	$ 2,750

Goddwill And Other Intangible A

Goddwill And Other Intangible Assets (Schedule Of Goodwill) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Goodwill [Line Items]
Goodwill, Beginning Balance	$ 86,326	$ 79,326
Acquisition of Magnus Pacific		7,000
Impairment of goodwill	(2,750)
Goodwill, Ending Balance	83,576	86,326
Dredging Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	76,576	76,576
Goodwill, Ending Balance	76,576	76,576
Demolition Segment [Member]
Goodwill [Line Items]
Goodwill, Beginning Balance	9,750	2,750
Acquisition of Magnus Pacific		7,000
Impairment of goodwill	(2,750)
Goodwill, Ending Balance	$ 7,000	$ 9,750

Goodwill And Other Intangible56

Goodwill And Other Intangible Assets (Net Book Value Of Identifiable Assetsl) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Finite Lived Intangible Assets [Line Items]
Cost	$ 5,428	$ 11,757
Accumulated amortization	3,000	2,794
Net	2,428	8,963
Non-compete Agreements [Member]
Finite Lived Intangible Assets [Line Items]
Cost	3,085	3,085
Accumulated amortization	1,625	940
Net	1,460	2,145
Trade Names [Member]
Finite Lived Intangible Assets [Line Items]
Cost	1,037	1,037
Accumulated amortization	873	185
Net	164	852
Other [Member]
Finite Lived Intangible Assets [Line Items]
Cost	1,306	1,306
Accumulated amortization	502	240
Net	$ 804	1,066
Customer Relationships [Member]
Finite Lived Intangible Assets [Line Items]
Cost		51
Accumulated amortization		34
Net		17
Backlog [Member]
Finite Lived Intangible Assets [Line Items]
Cost		6,278
Accumulated amortization		1,395
Net		$ 4,883

Accrued Expenses (Details)

Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Payables And Accruals [Abstract]
Insurance	$ 16,291	$ 16,778
Accumulated deficit in joint venture	15,408	10,383
Payroll and employee benefits	13,317	8,808
Interest	8,743	8,270
Fuel hedge contracts	4,388	3,029
Income and other taxes	3,726	5,857
Percentage of completion adjustment	2,837	1,870
Other	7,567	15,046
Total accrued expenses	$ 72,277	$ 70,041

Long-Term Debt (Schedule Of Lon

Long-Term Debt (Schedule Of Long-Term Debt) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Debt Disclosure [Abstract]
Revolving credit facility	$ 20,000
Equipment notes payable	3,972	$ 2,857
Notes payable	60,595	54,620
7.375% senior notes	274,909	274,880
Line of credit, senior note payable, equipment notes payable and senior note	359,476	332,357
Current portion of equipment note payable	(1,293)	(736)
Current portion of note payable	(6,213)	(5,123)
Capital leases (included in other long term liabilities)	(2,679)	(2,121)
Long term debt	$ 349,291	$ 324,377

Long-Term Debt (Narrative) (Det

Long-Term Debt (Narrative) (Details) - USD ($)	Nov. 04, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Jun. 04, 2015	Feb. 01, 2015	Nov. 04, 2014	Dec. 31, 2011
Debt Instrument [Line Items]
Net book value of related assets				$ 151,330,000
Minimum fixed charge coverage ratio under sixth Term Loan Facility covenant amendment	3.00%
Maximum leverage ratio under sixth Term Loan Facility covenant amendment	1.25%
Net Leverage Ratio				4.50%
Fixed Charge Coverage Ratio				1.25%
Revolving credit facility				$ 20,000,000
Letters of credit outstanding				81,943,000
Letter of credit remaining borrowing capacity				108,057,000
Borrowed aggregate principal amount				2,640,000	$ 47,360,000
7.375% senior notes				274,909,000	274,880,000
Purchases of property and equipment				74,455,000	91,910,000	$ 66,654,000
Amortization of deferred financing fees				1,729,000	$ 1,453,000	$ 1,153,000
Magnus Pacific Acquisition [Member]
Debt Instrument [Line Items]
Purchases of property and equipment			$ 15,569,000
Term Loan Facility [Member]
Debt Instrument [Line Items]
Net book value of related assets				$ 49,132,000
Debt instrument, face amount									$ 50,000,000
Debt Instrument, Term				5 years
Term Loan Facility Bear Interest Fixed Rate				4.655%
Debt Instrument, Interest Rate, Increase (Decrease)				2.00%
Percentage of principal to be repaid yearly during first two years of term				10.00%
Percentage of principal to be repaid yearly during third and fourth years of term				20.00%
Percentage of principal to be repaid during fifth year of term				25.00%
Senior Notes [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage				7.375%
Debt instrument, face amount								$ 25,000,000
7.375% senior notes				$ 274,909,000
Promissory Note [Member]
Debt Instrument [Line Items]
Secured Debt				$ 8,100,000
Adjustment to fair value of debt		$ 7,013,000
Fair value of debt		0
Maximum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				2.50%
Maximum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				1.50%
Minimum [Member] | LIBOR Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				1.50%
Minimum [Member] | Base Rate [Member]
Debt Instrument [Line Items]
Debt Instrument, Basis Spread on Variable Rate				0.50%
7.375% Senior Notes Due In 2019 [Member]
Debt Instrument [Line Items]
Potential senior notes to be issued under sixth Term Loan Facility amendment	$ 50,000,000
Debt Instrument, Interest Rate, Stated Percentage	7.375%			7.375%
Debt instrument, face amount				$ 275,000,000
7.375% senior notes										$ 250,000,000
Maturity date				Feb. 1, 2019
5.75% Senior Notes Due In 2023 [Member] | Magnus Pacific Acquisition [Member]
Debt Instrument [Line Items]
Debt Instrument, Interest Rate, Stated Percentage			5.75%
Adjustment to fair value of debt		7,013,000
Fair value of debt		$ 0
Operating leases expiration year				2,023
Credit Agreement [Member]
Debt Instrument [Line Items]
Business Combination, Contingent Consideration, Liability	$ 11,400,000
If Redeemed In 2015 [Member] | 7.375% Senior Notes Due In 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage				103.70%
If Redeemed In 2016 [Member] | 7.375% Senior Notes Due In 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage				101.80%
If Redeemed After 2016 [Member] | 7.375% Senior Notes Due In 2019 [Member]
Debt Instrument [Line Items]
Debt Instrument, Redemption Price, Percentage				100.00%
Revolving Credit Facility [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							$ 210,000,000
Line of credit facility optional increase capacity							15,000,000
Revolving credit facility, interest rate description				The Credit Agreement is secured by a substantial portion of the Company’s operating equipment with a net book value at December 31, 2015 of $162,037. Depending on the Company’s consolidated leverage ratio (as defined in the Credit Agreement), borrowings under the amended revolving credit facility will bear interest at the option of the Company at either a LIBOR rate plus a margin of between 1.50% to 2.50% per annum or a base rate plus a margin of between 0.50% to 1.50% per annum.
Multicurrency [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							50,000,000
Swingline Loans [Member]
Debt Instrument [Line Items]
Line of credit facility, maximum borrowing capacity							$ 10,000,000

Long-Term Debt (Maturities Of L

Long-Term Debt (Maturities Of Long-Term Debt) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Debt Disclosure [Abstract]
2,016	$ 21,498
2,017	16,145
2,018	11,421
2,019	295,461
2,020	1,815
Thereafter	8,800
Total	$ 355,140

Fair Value Measurements (Fair V

Fair Value Measurements (Fair Value Measurements At Reporting Date Using) (Details) - Fuel Hedge Contracts [Member] - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 4,388	$ 3,029
Fair Value, Inputs, Level 2 [Member]
Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items]
Fair Value, Net Asset (Liability)	$ 4,388	$ 3,029

Fair Value Measurements (Narrat

Fair Value Measurements (Narrative) (Details) gal in Millions	3 Months Ended	12 Months Ended
	Jun. 30, 2015USD ($)	Dec. 31, 2015USD ($)Contract$ / galgal	Nov. 04, 2015	Dec. 31, 2014USD ($)Contract
Derivatives Fair Value [Line Items]
Derivative underlying hedge percent		80.00%
Derivative, Nonmonetary Notional Amount, Volume | gal		9.2
Fair value hedge liabilities		$ 4,388,000		$ 3,029,000
Impairment of goodwill		2,750,000
7.375% Senior Notes Due In 2019 [Member]
Derivatives Fair Value [Line Items]
Debt instrument, face amount		$ 275,000,000
Stated interest rate		7.375%	7.375%
Maturity date		Feb. 1, 2019
7.375% Senior Notes Due In 2019 [Member] | Fair Value, Inputs, Level 1 [Member]
Derivatives Fair Value [Line Items]
Fair value of debt		$ 255,750,000
Terra Contracting Services [Member]
Derivatives Fair Value [Line Items]
Impairment of goodwill	$ 2,750,000
Minimum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		1.32
Maximum [Member]
Derivatives Fair Value [Line Items]
Fixed price range | $ / gal		2.11
Foreign Exchange Contract [Member]
Derivatives Fair Value [Line Items]
Number of outstanding contracts | Contract		0		0

Fair Value Measurements (Schedu

Fair Value Measurements (Schedule of Balance Sheet Location Fuel Hedge Contracts) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Derivatives Fair Value [Line Items]
Fair value hedge liabilities	$ 4,388	$ 3,029
Designated as Hedging Instrument [Member] | Accrued Liabilities [Member] | Fuel Hedge Contracts [Member]
Derivatives Fair Value [Line Items]
Fair value hedge liabilities	$ 4,388	$ 3,029

Fair Value Measurements (Fair64

Fair Value Measurements (Fair Value Measurements Using Significant Unobservable) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Impairment of goodwill	$ (2,750)
Fair Value, Inputs, Level 3 [Member]
Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation [Line Items]
Beginning balance	86,326
Impairment of goodwill	(2,750)
Ending balance	$ 83,576

Fair Value Measurements (Change

Fair Value Measurements (Changes In Components Of Accumulated Other Comprehensive Income) (Details) - USD ($) $ in Thousands		12 Months Ended
		Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Fair Value Disclosures [Abstract]
Cumulative translation adjustments—net of tax		$ (1,249)	$ (62)	$ (397)
Reclassification of derivative losses (gains) to earnings—net of tax			(332)	270
Change in fair value of derivatives—net of tax			133	34
Net unrealized (gain) loss on derivatives—net of tax	[1]		(199)	304
Other comprehensive loss—net of tax		$ (1,249)	$ (261)	$ (93)
[1]	Net of income tax (provision) benefit of $(132) and $204 for the years ended December 31, 2014 and 2013, respectively.

Fair Value Measurements (Adjust

Fair Value Measurements (Adjustments Reclassified From Accumulated Balances Other Comprehensive Loss To Earnings) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Derivative Instruments Gain Loss [Line Items]
Costs of contract revenues	$ (760,955)	$ (714,335)	$ (631,123)
Income tax (provision) benefit	(2,497)	(11,530)	10,460
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION	$ (6,189)	10,295	(34,361)
Fuel Hedge Contracts [Member] | Accumulated Net Gain Loss From Designated Or Qualifying Cash Flow Hedges | Reclassification Out Of Accumulated Other Comprehensive Income
Derivative Instruments Gain Loss [Line Items]
Costs of contract revenues		(286)	450
Income tax (provision) benefit		46	180
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION		$ (332)	$ 270

Income Taxes (Income tax (Provi

Income Taxes (Income tax (Provision) Benefit from Continuing and Discontinuing Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
INCOME TAX (PROVISION) BENEFIT	$ 2,497	$ 11,530	$ (10,460)
Income tax benefit from discontinued operations		8,744	19,116
Income tax benefit	$ 2,497	$ 20,274	$ 8,656

Income Taxes (Pre-Tax Income Fr

Income Taxes (Pre-Tax Income From Domestic And Foreign Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Domestic operations	$ (35,996)	$ (20,823)	$ 23,716
Foreign operations	27,310	30,011	6,601
Total pre-tax income (loss)	$ (8,686)	$ 9,188	$ 30,317

Income Taxes (Provision For Inc

Income Taxes (Provision For Income Taxes) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Current federal tax expense (benefit)		$ (174)	$ 8,384
Deferred federal tax expense (benefit)	$ (2,355)	(9,531)	2,107
Current state tax expense (benefit)	115	277	439
Deferred state tax expense (benefit)	(673)	(3,577)	(326)
Current foreign tax expense (benefit)	416	1,475	1,831
Deferred foreign tax expense (benefit)			(1,975)
Income tax provision (benefit)	$ (2,497)	$ (11,530)	$ 10,460

Income Taxes (Narrative) (Detai

Income Taxes (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Operating Loss Carryforwards [Line Items]
U.S. federal statutory income tax rate	35.00%	35.00%	35.00%
Worthless stock deduction		$ 9,631
Charitable contributions	$ 469	1,764
loss carryforwards for federal income tax purposes	70,534	55,328
Unrecognized tax benefits	157	442	$ 253	$ 471
Amount of unrecognized tax benefits which would have an impact on the effective tax rate	102	287
Interest and penalties recorded	23	24
Deferred tax assets current	8,953	14,485
State and Local Jurisdiction [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	128,460	105,458
Foreign Tax Authority [Member]
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards	11,507	13,039
Valuation allowance for net operating loss carryforwards	$ 3,586	$ 4,334

Income Taxes (Income Tax Provis

Income Taxes (Income Tax Provision (Benefit) Reconciliation) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Tax provision at statutory U.S. federal income tax rate	$ (3,040)	$ 3,214	$ 10,611
State income tax — net of federal income tax benefit	(676)	(2,726)	500
Worthless stock deduction		(9,631)
Charitable contributions	(469)	(1,764)
Adjustment to deferred tax depreciation	1,135	(1,670)
Change in deferred state tax rate		(811)
Research and development tax credits	(286)	(691)
Purchase price adjustment	393	(393)
Foreign income tax provision (benefit)			238
Changes in unrecognized tax benefits	(186)	127	(196)
Changes in valuation allowance	270	2,246	(500)
Other	362	569	(193)
Income tax provision (benefit)	$ (2,497)	$ (11,530)	$ 10,460

Income Taxes (Reconciliation Of

Income Taxes (Reconciliation Of Unrecognized Tax Benefits) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Income Tax Disclosure [Abstract]
Unrecognized tax benefits — January 1	$ 442	$ 253	$ 471
Gross increases — current period tax positions		270	42
Gross decreases — expirations		(65)	(201)
Gross decreases — tax positions in prior period	(285)	(16)	(59)
Unrecognized tax benefits — December 31,	$ 157	$ 442	$ 253

Income Taxes (Deferred Tax Asse

Income Taxes (Deferred Tax Assets (Liabilities) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014
Income Tax Disclosure [Abstract]
Accrued liabilities	$ 17,841	$ 13,288
Federal NOLs	24,687	19,365
Foreign NOLs	3,586	4,334
State NOLs	6,008	4,752
Tax credit carryforwards	5,374	4,651
Charitable contribution	2,233	1,764
Valuation allowance	(6,102)	(6,579)
Total deferred tax assets	53,627	41,575
Depreciation and amortization	(126,174)	(117,286)
Other liabilities	(1,459)	(1,811)
Total deferred tax liabilities	(127,633)	(119,097)
Net deferred tax liabilities	(74,006)	(77,522)
Net current deferred tax assets (included in other current assets)	8,953	14,485
Net noncurrent deferred tax liabilities	$ (74,006)	$ (92,007)

Share-Based Compensation (Narra

Share-Based Compensation (Narrative) (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Share-based compensation expense	$ 4,040	$ 2,694	$ 3,251
Weighted-average grant-date fair value of options granted		$ 4.23	$ 4.06
Total unrecognized compensation cost related to non-vested NQSOs and RSUs	5,234
Amount related to shares used for tax withholding obligations	$ 267	$ 497
Annual retainer per non-employee director, percentage paid in cash	50.00%
Annual retainer per non-employee director, percentage paid in common stock	50.00%
Shares of common stock received by employee directors	112	99		96
Restricted Stock Units (RSUs) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Total unrecognized compensation cost, weighted-average period of recognition	2 years 9 months 18 days
Non Qualified Stock Options (NQSO) [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Awards granted in period	0
Total unrecognized compensation cost, weighted-average period of recognition	1 year 1 month 6 days
Employees And Directors [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	5,800
Non-Employee Directors [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Annual retainer per non-employee director	$ 155
Chairman of the Board [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Additional annual retainer paid to non-employee director	$ 150
Additional percentage of annual retainer paid to non-employee director in common stock	50.00%
Additional percentage of annual retainer paid to non-employee director in cash	50.00%

Share-Based Compensation (Optio

Share-Based Compensation (Option Pricing Assumption (Details)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected volatility	53.90%	58.20%
Expected dividends	0.00%	0.00%
Expected term (in years)	7 years	6 years
Risk free rate	1.90%	1.00%

Share-Based Compensation (Summa

Share-Based Compensation (Summary Of Stock Option Activity) (Details) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)$ / sharesshares
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Outstanding as of January 1, 2015 | shares	1,889
Exercised | shares	(86)
Forfeited or Expired | shares	(77)
Outstanding as of December 31, 2015 | shares	1,726
Vested at December 31, 2015 | shares	1,447
Vested or expected to vest at December 31, 2015 | shares	1,724
Weighted average exercise price outstanding as of January 1, 2015 | $ / shares	$ 6.31
Weighted average exercise price, exercised | $ / shares	5.35
Weighted average exercise price, forfeited or expired | $ / shares	7.14
Weighted average exercise price outstanding as of December 31, 2015 | $ / shares	6.32
Weighted average exercise price, vested at December 31, 2015 | $ / shares	6.07
Weighted average exercise price, vested and expected to vest at December 31, 2015 | $ / shares	$ 6.32
Weighted average remaining contractual term, vested as of December 31, 2015	5 years 3 months 18 days
Weighted average remaining contractual term, vested and expected to vest as of December 31, 2015	5 years 9 months 18 days
Aggregate intrinsic value, vested at December 31, 2015 | $	$ 17
Aggregate intrinsic value, vested and expected to vest at December 31, 2015 | $	$ 17

Share-Based Compensation (Sum77

Share-Based Compensation (Summary Of Non-Vested Restricted Stock Units) (Details) - Restricted Stock Units (RSUs) [Member] shares in Thousands	12 Months Ended
	Dec. 31, 2015$ / sharesshares
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Options outstanding as of January 1, 2015 | shares	2,063
Options granted | shares	784
Options vested | shares	(160)
Options forfeited | shares	(491)
Options outstanding as of December 31, 2015 | shares	2,196
Options expected to vest at December 31, 2015 | shares	1,140
Weighted-average grant-date fair value as of January 1, 2015 | $ / shares	$ 6.91
Weighted-average grant-date fair value, granted | $ / shares	5.65
Weighted-average grant-date fair value, vested | $ / shares	6.42
Weighted-average grant-date fair value, forfeited | $ / shares	6.79
Weighted-average grant-date fair value as of December 31, 2015 | $ / shares	6.57
Weighted-average grant-date fair value, expected to vest at December 31, 2015 | $ / shares	$ 6.37

Retirement Plans (Narrative) (D

Retirement Plans (Narrative) (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2015USD ($)item	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Defined Contribution Plan Disclosure [Line Items]
Number of sponsored 401(k) plans | item	4
Expense for matching and discretionary contributions	$ 6,772	$ 5,256	$ 5,123
Contributes to various multiemployer pension plans	$ 4,990	$ 4,383	$ 3,870
Maximum [Member]
Defined Contribution Plan Disclosure [Line Items]
Multiemployer plans collective-bargaining arrangement percentage of contributions	5.00%

Commitments And Contingencies79

Commitments And Contingencies (Narrative) (Details) - USD ($)	Feb. 05, 2016	Jan. 14, 2015	Jan. 31, 2014	May. 31, 2013	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Commitments And Contingencies [Line Items]
Outstanding performance bonds					$ 1,065,961,000
Revenue value remaining from outstanding performance bonds					622,765,000
Proceeds from Legal Settlements		$ 5,309,000
Proceeds from Lines of Credit				$ 13,600,000
Gain (Loss) Related to Litigation Settlement			$ 10,500,000				$ 13,372,000
Funds remitted			$ 3,100,000
Rent expense under long term operating lease arrangements					21,697,000	$ 25,318,000	$ 21,620,000
Subsequent Event [Member]
Commitments And Contingencies [Line Items]
Tentative settlement subject to final documentation	$ 275,000
Discontinued Operations [Member]
Commitments And Contingencies [Line Items]
Outstanding performance bonds					41,082,000
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

Commitments And Contingencies80

Commitments And Contingencies (Future Minimum Operating Lease Payments) (Details) $ in Thousands	Dec. 31, 2015USD ($)
Commitments And Contingencies Disclosure [Abstract]
2,016	$ 22,516
2,017	20,800
2,018	13,034
2,019	8,802
2,020	6,246
Thereafter	10,866
Total minimum operating lease payments	$ 82,264

Investments (Details)

Investments (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Schedule Of Equity Method Investments [Line Items]
Other current assets	$ 59,690	$ 64,667
Accumulated deficit in joint venture	$ 15,408	$ 10,383
Amboy Aggregates [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership percentage	50.00%
Land sold	$ 29,729
Lower Main Street Development [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership percentage	50.00%
TerraSea Environmental Solutions [Member]
Schedule Of Equity Method Investments [Line Items]
Ownership percentage		50.00%
Other current assets	$ 27,592	$ 22,898
Accumulated deficit in joint venture	14,271	$ 10,383
Provision for losses to be assumed	$ 1,983

Investment (Summary Financial I

Investment (Summary Financial Information Under Equity Method) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Amboy Aggregates [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Revenue	$ 139	$ 13,784	$ 24,399
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	(1,363)	(118)	4,142
Equity Method Investment, Summarized Financial Information, Income (Loss) from Continuing Operations before Extraordinary Items	(3,152)	11,326	2,329
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	(3,152)	9,527	3,998
Lower Main Street Development [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Revenue		180	180
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)		180	180
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	28	14,803	175
TerraSea Environmental Solutions [Member]
Schedule Of Equity Method Investments [Line Items]
Equity Method Investment, Summarized Financial Information, Revenue	6,960	11,278	7,368
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	(3,800)	(19,153)	(956)
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	$ (3,800)	$ (19,856)	$ (956)

Related Party Transactions (Det

Related Party Transactions (Details) - USD ($)	1 Months Ended	12 Months Ended
	Oct. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Related Party Transaction [Line Items]
Rent expense		$ 21,697,000	$ 25,318,000	$ 21,620,000
Rivers And Lakes Group [Member]
Related Party Transaction [Line Items]
Rent expense		0	0	95,000
NASDI And Yankee [Member]
Related Party Transaction [Line Items]
Rent and property taxes			375,000	449,000
Lease termination fees	$ 490,000
Rent expense		0
Terra Contracting L L C
Related Party Transaction [Line Items]
Rent expense		243,000	243,000	243,000
Magnus Real Estate Group L L C
Related Party Transaction [Line Items]
Rent expense		$ 402,000	$ 46,000	$ 0

Business Combinations And Dis84

Business Combinations And Dispositions (Narrative) (Details) - USD ($) shares in Thousands	Nov. 04, 2014	Apr. 23, 2014	Jun. 30, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2013
Business Acquisition [Line Items]
GOODWILL				$ 86,326,000	$ 83,576,000	$ 79,326,000
Gain on bargain purchase acquisition				2,197,000
Magnus Pacific Acquisition [Member]
Business Acquisition [Line Items]
Base purchase price	$ 40,000,000
Payments for Previous Acquisition	$ 25,000,000
Maximum potential aggregate earnout payment				11,400,000
Fair value of earnout liability				8,024,000	$ 8,457,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables				57,303,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Property, Plant, and Equipment				11,573,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Intangibles				8,422,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Liabilities				27,586,000
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Liabilities, Accounts Payable				20,732,000
GOODWILL				$ 7,000,000
Finite-Lived intangible assets amortization Period				5 years
Right to receive, in aggregate maximum, shares				1,500
Magnus Pacific Acquisition [Member] | Excess Of Billings [Member]
Business Acquisition [Line Items]
Business Combination, Recognized Identifiable Assets Acquired and Liabilities Assumed, Current Assets, Receivables				$ 41,067,000
Magnus Pacific Acquisition [Member] | 5.75% Senior Notes Due In 2023 [Member]
Business Acquisition [Line Items]
Adjustment to fair value of debt			$ 7,013,000
Fair value of debt			$ 0
NASDI, LLC and Yankee Environmental Services, LLC
Business Acquisition [Line Items]
Proceeds from Divestiture of Businesses		$ 5,309,000

Business Dispositions (Details)

Business Dispositions (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013
Business Combinations [Abstract]
Revenue	$ 14,803	$ 39,550
Loss before income taxes from discontinued operations	(19,167)	(55,530)
Loss on disposal of assets held for sale		(18,436)
Income tax benefit from discontinued operations	8,744	19,116
Loss from discontinued operations, net of income taxes	$ (10,423)	$ (54,850)

Business Combinations And Dis86

Business Combinations And Dispositions Unaudited Pro Forma) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenue as reported	$ 856,878	$ 806,831	$ 731,418
Revenue of purchased businesses for the period prior to the acquisition		106,723	87,943
Pro forma revenue		913,554	819,361
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$ (6,189)	10,295	(34,361)
Net income of Magnus including net income prior to acquisition and pro forma acquisition accounting adjustments		6,328	1,069
Pro forma net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		16,623	(33,292)
As Reported [Member]
Revenue as reported		806,831	731,418
GLDD Corporation [Member]
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		$ 10,295	$ (34,361)

Segment Information (Narrative)

Segment Information (Narrative) (Details) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2014USD ($)	Dec. 31, 2015USD ($)segment	Dec. 31, 2014USD ($)	Dec. 31, 2013USD ($)
Segment Reporting Information [Line Items]
Number of reportable segments | segment		2
Long-lived assets, net book value	$ 93,839	$ 83,397	$ 93,839
Gross Profit		95,923	92,496	$ 100,295
Landfill [Member]
Segment Reporting Information [Line Items]
Loss on sale of project		$ (7,446)
Single Customer Foreign Contract [Member]
Segment Reporting Information [Line Items]
Gross Profit			$ 22,418
Increase gross profit from foreign contract	$ 7,645
Dredging [Member] | Sales [Member] | Geographic Concentration Risk [Member] | Middle East [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage		14.70%
Dredging [Member] | Sales [Member] | Federal Government Agencies [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage		51.00%	60.40%	45.00%
Dredging [Member] | Accounts Receivable [Member] | Geographic Concentration Risk [Member] | Middle East [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage		24.60%	13.30%
Dredging [Member] | Accounts Receivable [Member] | Federal Government Agencies [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage		24.90%	45.90%

Segment Information (Segment Re

Segment Information (Segment Reporting By Segment) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Segment Reporting Information [Line Items]
CONTRACT REVENUES	$ 856,878	$ 806,831	$ 731,418
Operating income (loss)	22,959	23,853	51,401
Depreciation and amortization	64,585	50,129	46,622
Total assets	901,625	893,234	852,645
PROPERTY AND EQUIPMENT—Net	430,210	399,445	345,620
GOODWILL	83,576	86,326	79,326
INVESTMENTS IN JOINT VENTURES	3,761	7,889	8,256
Capital expenditures	89,279	92,078	62,002
Dredging Segment [Member]
Segment Reporting Information [Line Items]
Operating income (loss)	64,073	41,620	54,683
Depreciation and amortization	50,556	43,620	44,118
Total assets	875,797	815,683	821,253
PROPERTY AND EQUIPMENT—Net	397,468	366,027	330,689
GOODWILL	76,576	76,576	76,576
INVESTMENTS IN JOINT VENTURES	1	2,114	8,256
Capital expenditures	82,000	79,186	57,902
Environmental And Remediation Segment
Segment Reporting Information [Line Items]
Operating income (loss)	(41,114)	(17,767)	(3,282)
Depreciation and amortization	14,029	6,509	2,504
Total assets	127,907	134,324	98,505
PROPERTY AND EQUIPMENT—Net	32,742	33,418	14,931
GOODWILL	7,000	9,750	2,750
INVESTMENTS IN JOINT VENTURES	3,760	5,775
Capital expenditures	7,279	12,892	4,100
Operating Segment [ Member] | Dredging Segment [Member]
Segment Reporting Information [Line Items]
CONTRACT REVENUES	681,255	697,711	642,602
Operating Segment [ Member] | Environmental And Remediation Segment
Segment Reporting Information [Line Items]
CONTRACT REVENUES	181,710	114,412	94,840
Intersegment Revenue [Member]
Segment Reporting Information [Line Items]
CONTRACT REVENUES	(6,087)	(5,292)	(6,024)
Total assets	$ (102,080)	$ (56,773)	$ (67,113)

Segment Information (Dredging R

Segment Information (Dredging Revenue By Type Of Work) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	$ 856,878	$ 806,831	$ 731,418
Dredging [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	681,255	697,711	642,602
Dredging [Member] | Capital Dredging - U.S. [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	207,058	195,635	153,781
Dredging [Member] | Capital dredging - Foreign [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	139,945	155,000	138,436
Dredging [Member] | Beach Nourishment Dredging [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	184,060	194,219	228,868
Dredging [Member] | Maintenance Dredging [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	120,055	123,923	90,833
Dredging [Member] | Rivers & Lakes [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
Revenue as reported	$ 30,137	$ 28,934	$ 30,684

Segment Information (Revenues A

Segment Information (Revenues And Gross Profit From Foreign Operations) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Revenues From External Customers And Long Lived Assets [Line Items]
CONTRACT REVENUES	$ 856,878	$ 806,831	$ 731,418
Costs of contract revenues	(760,955)	(714,335)	(631,123)
GROSS PROFIT	95,923	92,496	100,295
Foreign [Member]
Revenues From External Customers And Long Lived Assets [Line Items]
CONTRACT REVENUES	139,945	155,000	138,436
Costs of contract revenues	(105,951)	(118,682)	(117,029)
GROSS PROFIT	$ 33,994	$ 36,318	$ 21,407

Subsidiary Guarantors (Narrativ

Subsidiary Guarantors (Narrative) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014
Condensed Financial Statements, Captions [Line Items]
7 3/8% SENIOR NOTES	$ 274,909	$ 274,880
Senior Notes [Member]
Condensed Financial Statements, Captions [Line Items]
7 3/8% SENIOR NOTES	$ 275,000
Debt Instrument, Interest Rate, Stated Percentage	7.375%
Owned Domestic Subsidiaries Percent	100.00%

Subsidiary Guarantors (Condense

Subsidiary Guarantors (Condensed Consolidated Balance Sheets) (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
ASSETS
Cash and cash equivalents	$ 14,184	$ 42,389	$ 75,338	$ 24,440
Current portion of accounts receivable—net	130,777	113,188
Contract revenues in excess of billings	81,195	82,557
Inventories	35,963	34,735
Prepaid expenses	7,924	4,708
Other current assets	59,690	64,667
Total current assets	329,733	342,244
PROPERTY AND EQUIPMENT—Net	430,210	399,445	345,620
GOODWILL	83,576	86,326	79,326
OTHER INTANGIBLE ASSETS — Net	2,428	8,963
INVENTORIES—Noncurrent	41,646	36,262
INVESTMENTS IN JOINT VENTURES	3,761	7,889	8,256
OTHER	10,271	12,105
TOTAL	901,625	893,234	852,645
LIABILITIES AND EQUITY
Accounts payable	118,846	119,971
Accrued expenses	72,277	70,041
Billings in excess of contract revenues	7,061	4,639
Current portion of long term debt	7,506	5,859
Total current liabilities	205,690	200,510
7 3/8% SENIOR NOTES	274,909	274,880
REVOLVING CREDIT FACILITY	20,000
NOTES PAYABLE	54,382	49,497
DEFERRED INCOME TAXES	74,006	92,007
OTHER	20,465	20,377
Total liabilities	649,452	637,271
TOTAL EQUITY	252,173	255,963	242,101	273,425
TOTAL	901,625	893,234
Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	12,035	41,724	71,939	24,272
Current portion of accounts receivable—net	129,978	115,739
Receivables from affiliates		152,822
Contract revenues in excess of billings	79,477	78,631
Inventories	35,963	34,735
Prepaid expenses	7,924	4,708
Other current assets	58,995	49,619
Total current assets	324,372	477,978
PROPERTY AND EQUIPMENT—Net	430,192	399,421
GOODWILL	83,576	86,326
OTHER INTANGIBLE ASSETS — Net	2,428	8,963
INVENTORIES—Noncurrent	41,646	36,262
INVESTMENTS IN JOINT VENTURES	3,761	7,889
RECEIVABLES FROM AFFILIATES	18,326
INVESTMENTS IN SUBSIDIARIES	3,706	3,757
OTHER	6,702	7,135
TOTAL	914,709	1,027,731
LIABILITIES AND EQUITY
Accounts payable	118,619	121,282
Payables to affiliates		196,829
Accrued expenses	62,861	60,415
Billings in excess of contract revenues	6,964	4,639
Current portion of long term debt	1,424	859
Total current liabilities	189,868	384,024
NOTES PAYABLE	323	7,553
DEFERRED INCOME TAXES		172
Deferred Tax Assets	(783)
PAYABLES TO AFFILIATES	85,859
OTHER	20,326	19,939
Total liabilities	295,593	411,688
TOTAL EQUITY	619,116	616,043
TOTAL	914,709	1,027,731
Non Guarantor Subsidiaries
ASSETS
Cash and cash equivalents	2,147	663	$ 3,399	$ 168
Current portion of accounts receivable—net	799	355
Receivables from affiliates		3,673
Contract revenues in excess of billings	1,718	4,236
Other current assets	218	431
Total current assets	4,882	9,358
PROPERTY AND EQUIPMENT—Net	18	24
RECEIVABLES FROM AFFILIATES	6,009
OTHER	3	3
TOTAL	10,912	9,385
LIABILITIES AND EQUITY
Accounts payable	227	1,389
Payables to affiliates		403
Accrued expenses	509	659
Billings in excess of contract revenues	97
Total current liabilities	833	2,451
PAYABLES TO AFFILIATES	3,505
Total liabilities	4,338	2,451
TOTAL EQUITY	6,574	6,934
TOTAL	10,912	9,385
Consolidation Eliminations
ASSETS
Current portion of accounts receivable—net		(2,906)
Receivables from affiliates		(212,300)
Contract revenues in excess of billings		(310)
Total current assets		(215,516)
RECEIVABLES FROM AFFILIATES	(95,073)
INVESTMENTS IN SUBSIDIARIES	(625,690)	(622,977)
TOTAL	(720,763)	(838,493)
LIABILITIES AND EQUITY
Accounts payable		(3,216)
Payables to affiliates		(212,300)
Total current liabilities		(215,516)
PAYABLES TO AFFILIATES	(95,073)
Total liabilities	(95,073)	(215,516)
TOTAL EQUITY	(625,690)	(622,977)
TOTAL	(720,763)	(838,493)
GLDD Corporation [Member]
ASSETS
Cash and cash equivalents	2	2
Receivables from affiliates		55,805
Other current assets	477	14,617
Total current assets	479	70,424
RECEIVABLES FROM AFFILIATES	70,738
INVESTMENTS IN SUBSIDIARIES	621,984	619,220
OTHER	3,566	4,967
TOTAL	696,767	694,611
LIABILITIES AND EQUITY
Accounts payable		516
Payables to affiliates		15,068
Accrued expenses	8,907	8,967
Current portion of long term debt	6,082	5,000
Total current liabilities	14,989	29,551
7 3/8% SENIOR NOTES	274,909	274,880
REVOLVING CREDIT FACILITY	20,000
NOTES PAYABLE	54,059	41,944
DEFERRED INCOME TAXES	74,789	91,835
PAYABLES TO AFFILIATES	5,709
OTHER	139	438
Total liabilities	444,594	438,648
TOTAL EQUITY	252,173	255,963
TOTAL	$ 696,767	$ 694,611

Subsidiary Guarantors (Conden93

Subsidiary Guarantors (Condensed Consolidated Statement Operations And Comprehensive Income) (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Condensed Financial Statements, Captions [Line Items]
CONTRACT REVENUES		$ 856,878	$ 806,831	$ 731,418
Costs of contract revenues		(760,955)	(714,335)	(631,123)
GROSS PROFIT		95,923	92,496	100,295
GENERAL AND ADMINISTRATIVE EXPENSES		71,069	67,911	68,039
PROCEEDS FROM LOSS OF USE CLAIM	$ (10,500)			(13,372)
Impairment of goodwill		2,750
(GAIN) LOSS ON SALE OF ASSETS—Net		(855)	732	(5,773)
Total operating income		22,959	23,853	51,401
Interest income (expense)—net		(24,365)	(19,967)	(21,941)
Equity in earnings (loss) of joint ventures		(6,051)	2,895	1,208
Gain on bargain purchase acquisition			2,197
Other income (expense)		(1,229)	210	(351)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		(8,686)	9,188	30,317
INCOME TAX (PROVISION) BENEFIT		2,497	11,530	(10,460)
Income from continuing operations		(6,189)	20,718	19,857
Loss from discontinued operations, net of income taxes			(10,423)	(54,850)
NET INCOME (LOSS)		(6,189)	10,295	(34,993)
Net loss attributable to noncontrolling interest				632
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION		(6,189)	10,295	(34,361)
Comprehensive income (loss)		(7,438)	10,034	(34,454)
Equity in earnings of joint ventures		6,051	(2,895)	(1,208)
Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
CONTRACT REVENUES		845,889	799,579	718,041
Costs of contract revenues		(750,509)	(707,474)	(614,908)
GROSS PROFIT		95,380	92,105	103,133
GENERAL AND ADMINISTRATIVE EXPENSES		71,069	67,905	68,029
PROCEEDS FROM LOSS OF USE CLAIM				(13,372)
Impairment of goodwill		2,750
(GAIN) LOSS ON SALE OF ASSETS—Net		(855)	732	(5,775)
Total operating income		22,416	23,468	54,251
Interest income (expense)—net		(526)	61	(136)
Equity in earnings (loss) of subsidiaries		8	20	212
Equity in earnings (loss) of joint ventures		(6,051)	2,895	1,208
Gain on bargain purchase acquisition			2,197
Other income (expense)		(1,222)	203	(3)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		14,625	28,844	55,532
INCOME TAX (PROVISION) BENEFIT		1,505	(18,173)	293
Income from continuing operations			10,671	55,825
Loss from discontinued operations, net of income taxes			(10,423)	(55,106)
NET INCOME (LOSS)		16,130	248	719
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION				719
Comprehensive income (loss)		16,130	49	1,023
Equity in earnings of joint ventures		6,051	(2,895)	(1,208)
Non Guarantor Subsidiaries
Condensed Financial Statements, Captions [Line Items]
CONTRACT REVENUES		13,698	26,282	24,932
Costs of contract revenues		(13,155)	(25,891)	(27,770)
GROSS PROFIT		543	391	(2,838)
GENERAL AND ADMINISTRATIVE EXPENSES			6	10
Total operating income		543	385	(2,848)
Interest income (expense)—net			(261)	(256)
Other income (expense)		(7)	7	(348)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		536	131	(3,452)
INCOME TAX (PROVISION) BENEFIT		(376)	(409)	4
Income from continuing operations			(278)	(3,448)
Loss from discontinued operations, net of income taxes			(1,343)	(1,448)
NET INCOME (LOSS)		160	(1,621)	(4,896)
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION				(4,896)
Comprehensive income (loss)		(1,089)	(1,683)	(5,293)
Consolidation Eliminations
Condensed Financial Statements, Captions [Line Items]
CONTRACT REVENUES		(2,709)	(19,030)	(11,555)
Costs of contract revenues		2,709	19,030	11,555
Equity in earnings (loss) of subsidiaries		(16,290)	(10,393)	(59,689)
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		(16,290)	(10,393)	(59,689)
Income from continuing operations			(10,393)	(59,689)
Loss from discontinued operations, net of income taxes			11,766	63,866
NET INCOME (LOSS)		(16,290)	1,373	4,177
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION				4,177
Comprehensive income (loss)		(15,041)	1,634	4,270
GLDD Corporation [Member]
Condensed Financial Statements, Captions [Line Items]
(GAIN) LOSS ON SALE OF ASSETS—Net				2
Total operating income				(2)
Interest income (expense)—net		(23,839)	(19,767)	(21,549)
Equity in earnings (loss) of subsidiaries		16,282	10,373	59,477
INCOME (LOSS) FROM CONTINUING OPERATIONS BEFORE INCOME TAXES		(7,557)	(9,394)	37,926
INCOME TAX (PROVISION) BENEFIT		1,368	30,112	(10,757)
Income from continuing operations			20,718	27,169
Loss from discontinued operations, net of income taxes			(10,423)	(62,162)
NET INCOME (LOSS)		(6,189)	10,295	(34,993)
Net loss attributable to noncontrolling interest				632
NET INCOME (LOSS) ATTRIBUTABLE TO COMMON STOCKHOLDERS OF GREAT LAKES DREDGE & DOCK CORPORATION			10,295	(34,361)
Comprehensive income (loss)		$ (7,438)	$ 10,034	$ (34,454)

Subsidiary Guarantors (Conden94

Subsidiary Guarantors (Condensed Consolidated of Cash Flow) (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
OPERATING ACTIVITIES:
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations	$ 29,122	$ 67,154	$ 86,347
Net cash flows used in operating activities of discontinued operations		(18,352)	(11,524)
Cash provided by operating activities	29,122	48,802	74,823
INVESTING ACTIVITIES:
Purchases of property and equipment	(74,455)	(91,910)	(66,654)
Proceeds from dispositions of property and equipment	1,322	68	6,953
Payments for acquisitions of businesses, net of cash acquired		(27,048)
Payments On Vendor Performance Obligations		(3,100)	13,600
Net cash flows used in investing activities of continuing operations	(73,133)	(121,990)	(46,101)
Net cash flows provided by (used in) investing activities of discontinued operations		5,275	(153)
Cash used in investing activities	(73,133)	(116,715)	(46,254)
FINANCING ACTIVITIES:
Proceeds from term loan facility	2,640	47,360
Repayments of term loan facility	(5,000)	(417)
Proceeds from issuance of 7 3/8% senior notes		24,880
Deferred financing fees	(111)	(2,532)
Repayment of long term note payable	(443)		(13,047)
Taxes paid on settlement of vested share awards	(267)	(497)	(308)
Purchase of noncontrolling interest		(205)	(3)
Proceeds from equipment debt	410
Repayments of equipment debt	(1,201)	(235)
Exercise of stock options and purchases from employee stock plans	1,365	1,568	668
Excess income tax benefit from share-based compensation	(57)	206	154
Purchase of treasury stock	(1,433)
Borrowings under revolving loans	179,500	236,500	227,000
Repayments of revolving loans	(159,500)	(271,500)	(192,000)
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations			22,464
Cash provided by financing activities	15,903	35,128	22,464
Effect of foreign currency exchange rates on cash and cash equivalents	(97)	(164)	(135)
Net increase (decrease) in cash and cash equivalents	(28,205)	(32,949)	50,898
Cash and cash equivalents at beginning of period	42,389	75,338	24,440
Cash and cash equivalents at end of period	14,184	42,389	75,338
Guarantor Subsidiaries
OPERATING ACTIVITIES:
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations		63,276	126,736
Net cash flows used in operating activities of discontinued operations		(17,328)	(5,049)
Cash provided by operating activities	52,498	45,948	121,687
INVESTING ACTIVITIES:
Purchases of property and equipment	(74,455)	(91,910)	(66,654)
Proceeds from dispositions of property and equipment	1,322	68	6,953
Payments for acquisitions of businesses, net of cash acquired		(2,048)
Payments On Vendor Performance Obligations		(3,100)	13,600
Net change in accounts with affiliates from investing activities	(29,402)	68,187	(37,282)
Net cash flows used in investing activities of continuing operations		(28,803)	(83,383)
Net cash flows provided by (used in) investing activities of discontinued operations		5,275	(153)
Cash used in investing activities	(102,535)	(23,528)	(83,536)
FINANCING ACTIVITIES:
Repayment of long term note payable			(2,500)
Net change in accounts with affiliates	4,291
Intercompany dividends		(52,400)
Capital contributions	17,258
Repayments of equipment debt	(1,201)	(235)
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations			(2,500)
Cash used in financing activities of discontinued operations			12,016
Cash provided by financing activities	20,348	(52,635)	9,516
Net increase (decrease) in cash and cash equivalents	(29,689)	(30,215)	47,667
Cash and cash equivalents at beginning of period	41,724	71,939	24,272
Cash and cash equivalents at end of period	12,035	41,724	71,939
Non Guarantor Subsidiaries
OPERATING ACTIVITIES:
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations		999	(7,748)
Net cash flows used in operating activities of discontinued operations		(1,024)	(6,475)
Cash provided by operating activities	312	(25)	(14,223)
INVESTING ACTIVITIES:
Net change in accounts with affiliates from investing activities			(302)
Net cash flows used in investing activities of continuing operations			(302)
Cash used in investing activities			(302)
FINANCING ACTIVITIES:
Net change in accounts with affiliates	1,269	(2,547)	10,342
Capital contributions			926
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations			11,268
Cash used in financing activities of discontinued operations			6,623
Cash provided by financing activities	1,269	(2,547)	17,891
Effect of foreign currency exchange rates on cash and cash equivalents	(97)	(164)	(135)
Net increase (decrease) in cash and cash equivalents	1,484	(2,736)	3,231
Cash and cash equivalents at beginning of period	663	3,399	168
Cash and cash equivalents at end of period	2,147	663	3,399
Consolidation Eliminations
INVESTING ACTIVITIES:
Net change in accounts with affiliates from investing activities	41,624	(68,187)	37,584
Net cash flows used in investing activities of continuing operations		(68,187)	37,584
Cash used in investing activities	41,624	(68,187)	37,584
FINANCING ACTIVITIES:
Net change in accounts with affiliates	(41,624)	68,187	(18,945)
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations			(18,945)
Cash used in financing activities of discontinued operations			(18,639)
Cash provided by financing activities	(41,624)	68,187	(37,584)
GLDD Corporation [Member]
OPERATING ACTIVITIES:
NetCashProvidedByUsedInOperatingActivitiesContinuingOperations		2,879	(32,641)
Cash provided by operating activities	(23,688)	2,879	(32,641)
INVESTING ACTIVITIES:
Payments for acquisitions of businesses, net of cash acquired		(25,000)
Net change in accounts with affiliates from investing activities	(12,222)
Net cash flows used in investing activities of continuing operations		(25,000)
Cash used in investing activities	(12,222)	(25,000)
FINANCING ACTIVITIES:
Proceeds from term loan facility	2,640	47,360
Repayments of term loan facility	(5,000)	(417)
Proceeds from issuance of 7 3/8% senior notes		24,880
Deferred financing fees	(111)	(2,532)
Repayment of long term note payable	(443)		(10,547)
Taxes paid on settlement of vested share awards	(267)	(497)	(308)
Purchase of noncontrolling interest		(205)	(3)
Net change in accounts with affiliates	36,064	(65,640)	8,603
Intercompany dividends		52,400
Capital contributions	(17,258)		(926)
Proceeds from equipment debt	410
Exercise of stock options and purchases from employee stock plans	1,365	1,568	668
Excess income tax benefit from share-based compensation	(57)	206	154
Purchase of treasury stock	(1,433)
Borrowings under revolving loans	179,500	236,500	227,000
Repayments of revolving loans	(159,500)	(271,500)	(192,000)
NetCashProvidedByUsedInFinancingActivitiesContinuingOperations			32,641
Cash provided by financing activities	35,910	22,123	$ 32,641
Net increase (decrease) in cash and cash equivalents		2
Cash and cash equivalents at beginning of period	2
Cash and cash equivalents at end of period	$ 2	$ 2

Schedule II-Valuation And Qua95

Schedule II-Valuation And Qualifying Accounts (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	$ 7,157	$ 4,034	$ 4,403
Additions charged to costs and expenses	446	4,174	(369)
Deductions	(748)	(1,051)
Ending Balance	6,855	7,157	4,034
Allowance for Doubtful Accounts [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	578	1,529	1,051
Additions charged to costs and expenses	176	100	478
Deductions		(1,051)
Ending Balance	754	578	1,529
Valuation Allowance of Deferred Tax Assets [Member]
Valuation and Qualifying Accounts Disclosure [Line Items]
Beginning Balance	6,579	2,505	3,352
Additions charged to costs and expenses	270	4,074	(847)
Deductions	(748)
Ending Balance	$ 6,101	$ 6,579	$ 2,505