Great Lakes Dredge & Dock (GLDD) 10-Q 7 May 14 2014 Q1 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	3 Months Ended
	Mar. 31, 2014	2-May-14
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	31-Mar-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q1	'
Trading Symbol	'GLDD	'
Entity Registrant Name	'Great Lakes Dredge & Dock CORP	'
Entity Central Index Key	'0001372020	'
Current Fiscal Year End Date	'--12-31	'
Entity Filer Category	'Accelerated Filer	'
Entity Common Stock, Shares Outstanding	'	59,815,840

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$58,695	$75,338
Accounts receivable-net	65,507	96,515
Contract revenues in excess of billings	93,061	67,432
Inventories	34,707	32,500
Prepaid Expense and Other Assets, Current	39,461	44,164
Assets Held-for-sale, Current	32,773	45,104
Total current assets	324,204	361,053
PROPERTY AND EQUIPMENT-Net	356,986	345,620
GOODWILL AND OTHER INTANGIBLE	81,047	81,302
INVENTORIES-Noncurrent	36,707	38,496
INVESTMENTS IN JOINT VENTURES	7,055	8,256
ASSETS HELD FOR SALE-Noncurrent	9,274	8,856
OTHER	10,517	9,062
TOTAL	825,790	852,645
CURRENT LIABILITIES:	'	'
Accounts payable	109,535	116,121
Accrued expenses	32,251	38,531
Billings in excess of contract revenues	4,961	6,754
Liabilities held for sale	26,581	32,493
Total current liabilities	173,328	193,899
7 3/8% SENIOR NOTES	250,000	250,000
REVOLVING CREDIT FACILITY	37,000	35,000
DEFERRED INCOME TAXES	107,931	108,511
Liabilities held for sale, noncurrent	707	1,212
OTHER	19,124	21,922
Total liabilities	588,090	610,544
EQUITY:	'	'
Common stock-$.0001 par value; 90,000 authorized, 59,784 and 59,670 shares issued and outstanding at March 31, 2014 and December 31, 2013, respectively.	6	6
Additional paid-in capital	275,610	275,183
Accumulated deficit	-36,965	-31,770
Accumulated other comprehensive loss	-951	-473
Total Great Lakes Dredge & Dock Corporation equity	237,700	242,946
NONCONTROLLING INTERESTS	'	-845
Total equity	237,700	242,101
TOTAL	$825,790	$852,645

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Mar. 31, 2014	Dec. 31, 2013
Consolidated Balance Sheets [Abstract]	'	'
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	90,000	90,000
Common stock, shares issued	59,784	59,359
Common stock, shares outstanding	59,625	59,359

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Operations (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Consolidated Statements Of Operations [Abstract]	'	'
CONTRACT REVENUES	$174,382	$180,153
COSTS OF CONTRACT REVENUES	153,475	149,419
GROSS PROFIT	20,907	30,734
OPERATING EXPENSES:	'	'
GENERAL AND ADMINISTRATIVE EXPENSES	17,870	16,236
Loss on sale of assets-net	152	2
Total operating income	2,885	14,496
OTHER EXPENSE:	'	'
Interest expense-net	-5,016	-5,733
Equity in loss of joint ventures	-1,843	-591
Loss on foreign currency transactions-net	65	36
Income (loss) from continuing operations before income taxes	-3,909	8,208
Income tax (provision) benefit	1,453	-3,456
Income (Loss) from Continuing Operations Attributable to Parent, Total	-2,456	4,752
Loss from discontinued operations, net of income taxes	-2,739	-4,341
Net income (loss)	-5,195	411
Net (income) loss attributable to noncontrolling interests	'	22
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	($5,195)	$433
Basic earnings (loss) per share attributable to continuing operations	($0.04)	$0.08
Basic loss per share attributable to discontinued operations, net of tax	($0.05)	($0.07)
Basic earnings (loss) per share attributable to Great Lakes Dredge & Dock Corporation	($0.09)	$0.01
Diluted earnings (loss) per share attributable to continuing operations	($0.04)	$0.08
Diluted loss per share attributable to discontinued operations, net of tax	($0.05)	($0.07)
Basic weighted average shares	59,708	59,369
Diluted earnings (loss) per share attributable to Great Lakes Dredge & Dock Corporation	($0.09)	$0.01
Diluted weighted average shares	59,708	60,017

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Consolidated Statements Of Comprehensive Income [Abstract]	'		'
Net income	($5,195)		$411
Currency translation adjustment-net of tax	-189	[1]	-6	[1]
Net unrealized (gain) loss on derivatives-net of tax (2)	-289	[2]	17	[2]
Other comprehensive income (loss)-net of tax	-478	[3]	11	[3]
Comprehensive income (loss)	-5,673		422
Comprehensive loss attributable to noncontrolling interests	'		22
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	($5,673)		$444
[1]	Net of income tax expense of $126 and $4 for three months ended March 31, 2014 and 2013, respectively.
[2]	Net of income tax (expense) benefit of $(194) and $11 for the three months ended March 31, 2014 and 2013, respectively.
[3]

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements Of Comprehensive Income (Parenthetical) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Consolidated Statements Of Comprehensive Income [Abstract]	'	'
Currency translation adjustment, tax	$126	$4
Reclassification of derivative gains (losses) to earnings, tax	($194)	$11

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Equity (USD $)	Common Stock [Member]	Additional Paid-In Capital [Member]	Retained Earnings [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Income (Loss)[Member]	Noncontrolling Interests [Member]	Total
In Thousands, except Share data
BALANCE - value at Dec. 31, 2012	$6	$271,418	$2,591	'	($380)	($210)	$273,425
BALANCE - shares at Dec. 31, 2012	59,359	'	'	'	'	'	'
Share-based compensation, Value	'	751	'	'	'	'	751
Share-based compensation, Shares	27	'	'	'	'	'	'
Vesting of restricted stock units, including impact of shares withheld for taxes, value	'	-28	'	'	'	'	-28
Vesting of restricted stock units, including impact of shares withheld for taxes, shares	5	'	'	'	'	'	'
Excess income tax benefit from share based compensation	'	15	'	'	'	'	15
Net income	'	'	433	'	'	-22	411
Other comprehensive loss-net of tax	'	'	'	'	11	'	11	[1]
BALANCE - value at Mar. 31, 2013	6	272,156	3,024	'	-369	-232	274,585
BALANCE - shares at Mar. 31, 2013	59,391	'	'	'	'	'	'
BALANCE - value at Dec. 31, 2013	6	275,183	'	-31,770	-473	-845	242,101
BALANCE - shares at Dec. 31, 2013	59,670	'	'	'	'	'	'
Share-based compensation, Value	'	996	'	'	'	'	996
Share-based compensation, Shares	40	'	'	'	'	'	'
Exercise of stock options, Value	'	415	'	'	'	'	415
Exercise of stock options, Shares	74	'	'	'	'	'	'
Excess income tax benefit from share based compensation	'	4	'	'	'	'	4
Distributions paid to noncontrolling interests	'	-988	'	'	'	845	-143
Net income	'	'	'	-5,195	'	'	-5,195
Other comprehensive loss-net of tax	'	'	'	'	-478	'	-478	[1]
BALANCE - value at Mar. 31, 2014	$6	$275,610	'	($36,965)	($951)	'	$237,700
BALANCE - shares at Mar. 31, 2014	59,784	'	'	'	'	'	'
[1]

Condensed_Condensed_Consolidat

Condensed Condensed Consolidated Statements Of Cash Flows (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
OPERATING ACTIVITIES:	'	'
Nte income (loss)	($5,195)	$433
Loss from discontinued operations, net of income taxes	-2,739	-4,319
Income (loss) from continuing operations	-2,456	4,752
Adjustments to reconcile net income to net cash flows used in operating activities:	'	'
Depreciation and amortization	10,885	11,451
Equity in loss of joint ventures	1,843	591
Deferred income taxes	-3,125	-1,691
Loss on dispositions of property and equipment	152	2
Amortization of deferred financing fees	288	288
Unrealized foreign currency (gain) loss	-188	41
Share-based compensation expense	996	751
Excess income tax benefit from share based compensation	-4	-15
Changes in assets and liabilities:	'	'
Accounts receivable	30,390	921
Contract revenues in excess of billings	-25,457	-6,446
Inventories	-418	3,116
Prepaid expenses and other current assets	12,684	2,733
Accounts payable and accrued expenses	-14,070	-23,502
Billings in excess of contract revenues	-1,793	-2,340
Other noncurrent assets and liabilities	-1,082	-812
Net Cash Provided by (Used in) Operating Activities, Continuing Operations, Total	8,645	-10,160
Net cash flows used in operating activities of discontinued operations	-2,635	-3,072
Cash provided by (used in) operating activities	6,010	-13,232
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-21,631	-15,364
Proceeds from dispositions of property and equipment	64	58
Proceeds from vendor performance obligations	-3,100	'
Net Cash Provided by (Used in) Investing Activities, Continuing Operations, Total	-24,667	-15,306
Net cash flows used in investing activities of discontinued operations	-26	-150
Cash used in investing activities	-24,693	-15,456
FINANCING ACTIVITIES:	'	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	'	-28
Purchase of noncontrolling interest	-205	'
Exercise of stock	415	'
Excess income tax benefit from share-based compensation	4	15
Borrowings under revolving loans	40,000	79,500
Repayments of revolving loans	-38,000	-58,000
Net Cash Provided by (Used in) Financing Activities, Continuing Operations, Total	2,214	10,940
Net cash flows used in financing activities of discontinued operations	'	-25
Cash provided by financing activities	2,214	10,915
Effect of foreign currency exchange rates on cash and cash equivalents	-174	-24
Net decrease in cash and cash equivalents	-16,643	-17,797
Cash and cash equivalents at beginning of period	75,338	24,440
Cash and cash equivalents at end of period	58,695	6,643
Supplemental Cash Flow Information	'	'
Cash paid for interest	9,486	9,881
Cash paid (refunded) for income taxes	-12,449	241
Non-cash Investing and Financing Activities	'	'
Property and equipment purchased but not yet paid	10,235	6,253
Purchase of noncontrolling interest in non cash investing and financing activies	$988	'

Basis_of_presentation

Basis of presentation	3 Months Ended
	Mar. 31, 2014
Basis of presentation	'
Basis of presentation	'
	1.   Basis of presentation
	The unaudited condensed consolidated financial statements and notes herein should be read in conjunction with the audited consolidated financial statements of Great Lakes Dredge & Dock Corporation and Subsidiaries (the “Company” or “Great Lakes”) and the notes thereto, included in the Company’s Annual Report on Form 10-K for the year ended December 31, 2013. The condensed consolidated financial statements included herein have been prepared by the Company without audit, pursuant to the rules and regulations of the Securities and Exchange Commission (“SEC”). Certain information and footnote disclosures normally included in financial statements prepared in accordance with accounting principles generally accepted in the United States of America (“GAAP”) have been condensed or omitted pursuant to the SEC’s rules and regulations, although management believes that the disclosures are adequate and make the information presented not misleading. In the opinion of management, all adjustments, which are of a normal and recurring nature (except as otherwise noted), that are necessary to present fairly the Company’s financial position as of March 31, 2014, and its results of operations for the three months ended March 31, 2014 and 2013 and cash flows for the three months ended March 31, 2014 and 2013 have been included.
	The components of costs of contract revenues include labor, equipment (including depreciation, maintenance, insurance and long-term rentals), subcontracts, fuel and project overhead. Hourly labor is generally hired on a project-by-project basis. Costs of contract revenues vary significantly depending on the type and location of work performed and assets utilized. Generally, capital projects have the highest margins due to the complexity of the projects, while coastal protection projects have the most volatile margins because they are most often exposed to variability in weather conditions.
	The Company’s cost structure includes significant annual equipment-related costs, including depreciation, maintenance, insurance and long-term rentals. These costs have averaged approximately 22% to 23% of total costs of contract revenues over the prior three years. During the year, both 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 revenues recognized over the year, to better match revenues and expenses. Specifically, at each interim reporting date the Company compares actual revenues earned to date on its dredging contracts to expected annual revenues and recognizes 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.
	The Company has four operating segments that, through aggregation, comprise two reportable segments: dredging and environmental & remediation, previously referred to as the demolition segment. The historical demolition business has been retrospectively presented as discontinued operations and is no longer reflected in continuing operations. Four operating segments were aggregated into two reportable segments as the segments have similarity in economic margins, services, production processes, customer types, distribution methods and regulatory environment. The Company has determined that the operating segments are the Company’s four reporting units.
	The condensed consolidated results of operations and comprehensive income for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year.

Earnings_per_share

Earnings per share	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Earnings Per Share [Text Block]	'
	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 three months ended March 31, 2014, the dilutive effect of 789 thousand shares of stock options and restricted stock units were excluded from the diluted weighted-average common shares outstanding as the Company incurred a loss during this period. The impact of these shares would have been antidilutive. For the three months ended March 31, 2013,  zero options to purchase shares of common stock were excluded from the calculation of diluted earnings per share based on the application of the treasury stock method. The computations for basic and diluted earnings per share from continuing operations are as follows:
		Three Months Ended
	(shares in thousands)	March 31,
		2014		2013
	Income (loss) from continuing operations	$	-2,456	$	4,752
	Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation		-2,739		-4,319
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		-5,195		433
	Weighted-average common shares outstanding — basic		59,708		59,369
	Effect of stock options and restricted stock units		-		648
	Weighted-average common shares outstanding — diluted		59,708		60,017
	Earnings (loss) per share from continuing operations — basic	$	-0.04	$	0.08
	Earnings (loss) per share from continuing operations — diluted	$	-0.04	$	0.08

Accounts_Receivable_And_Contra

Accounts Receivable And Contracts In Progress	3 Months Ended
	Mar. 31, 2014
Accounts Receivable And Contracts In Progress [Abstract]	'
Accounts Receivables And Contracts In Progress	'
	3.   Accounts receivable and contracts in progress
	Accounts receivable at March 31, 2014 and December 31, 2013 are as follows:
		March 31,		December 31,
		2014		2013
	Completed contracts	$	15,248	$	17,361
	Contracts in progress		33,352		62,177
	Retainage		18,436		18,506
			67,036		98,044
	Allowance for doubtful accounts		-1,529		-1,529
	Total accounts receivable—net	$	65,507	$	96,515
	The components of contracts in progress at March 31, 2014 and December 31, 2013 are as follows:
		March 31,		December 31,
		2014		2013
	Costs and earnings in excess of billings:
	Costs and earnings for contracts in progress	$	704,049	$	435,470
	Amounts billed		-616,628		-370,730
	Costs and earnings in excess of billings for contracts in progress		87,421		64,740
	Costs and earnings in excess of billings for completed contracts		5,640		2,692
	Total contract revenues in excess of billings	$	93,061	$	67,432
	Billings in excess of costs and earnings:
	Amounts billed	$	-177,450	$	-156,794
	Costs and earnings for contracts in progress		172,489		150,040
	Total billings in excess of contract revenues	$	-4,961	$	-6,754

Accrued_Expenses

Accrued Expenses	3 Months Ended
	Mar. 31, 2014
Accrued Expenses [Abstract]	'
Accrued Expenses	'
	4.   Accrued expenses
	Accrued expenses at March 31, 2014 and December 31, 2013 are as follows:
		March 31,		December 31,
		2014		2013
	Payroll and employee benefits	$	10,171	$	13,664
	Insurance		9,426		8,649
	Income and other taxes		4,055		3,709
	Interest		3,308		8,066
	Percentage of completion adjustment		2,422		2,135
	Other		2,869		2,308
	Total accrued expenses	$	32,251	$	38,531

Longterm_Debt

Long-term Debt	3 Months Ended
	Mar. 31, 2014
Long-Term Debt [Abstract]	'
Long-Term Debt	'
	5.   Long-term debt
	On June 4, 2012, the Company entered into a senior revolving credit agreement (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 $175,000, subfacilities for the issuance of standby letters of credit up to a $125,000 sublimit, 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 $50,000. This 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.
	Depending on the Company’s consolidated leverage ratio (as defined in the Credit Agreement), borrowings under the revolving credit facility will bear interest at the option of the Company of 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 facility 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.
	In 2013, outstanding obligations under the Credit Agreement, which were previously unsecured, were secured by liens on certain of the Company’s vessels and all of its domestic accounts receivable, subject to the liens and interests of certain other parties holding first priority perfected liens. Under the terms of the Credit Agreement, the obligations thereunder that became secured could again become unsecured provided that (i) no event of default has occurred and is continuing, (ii) the Company has maintained for two consecutive quarters, and is projected to maintain for the next two consecutive quarters, a total leverage ratio less than or equal to 3.75 to 1.0 and (iii) the Company has delivered to the lenders its audited financial statements with respect to its fiscal year ending December 31, 2013. At March 31, 2014, the Credit Agreement remains secured by liens on certain of the Company’s vessels and all of its domestic accounts receivable.
	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. During a year, the Company frequently borrows and repays amounts under its revolving credit facility. As of March 31, 2014, the Company had $37,000 of borrowings on the revolver and $90,781 of letters of credit outstanding, resulting in $47,219 of availability under the Credit Agreement. At March 31, 2014, the Company was in compliance with its various financial covenants under its Credit Agreement.
	In addition to its Credit Agreement, the Company has a $24,000 international letter of credit facility that it uses for the performance and advance payment guarantees on the Company’s foreign contracts. As of March 31, 2014, Great Lakes had no letters of credit outstanding under this facility. At March 31, 2014, the Company also had $250,000 of 7.375% senior notes outstanding, which mature in February 2019.

Fair_Value_Measurements

Fair Value Measurements	3 Months Ended
	Mar. 31, 2014
Fair Value Measurements [Abstract]	'
Fair Value Measurements	'
	6.   Fair value measurements
	Fair value is defined as the exchange price that would be received for an asset or paid to transfer a liability (an exit price) in the principal or most advantageous market for the asset or liability in an orderly transaction between market participants on the measurement date. A fair value hierarchy has been established by GAAP that requires an entity to maximize the use of observable inputs and minimize the use of unobservable inputs when measuring fair value. The accounting guidance describes three levels of inputs that may be used to measure fair value:
	Level 1—Quoted prices in active markets for identical assets or liabilities.
	Level 2—Observable inputs other than Level 1 prices such as quoted prices for similar assets or liabilities; quoted prices in markets that are not active; or other inputs that are observable or can be corroborated by observable market data for substantially the full term of the assets or liabilities.
	Level 3—Unobservable inputs that are supported by little or no market activity and that are significant to the fair value of the assets or liabilities.
	The Company utilizes the market approach to measure fair value for its financial assets and liabilities. The market approach uses prices and other relevant information generated by market transactions involving identical or comparable assets or liabilities. At March 31, 2014 and December 31, 2013, the Company held certain derivative contracts that it uses to manage foreign currency risk and commodity price risk. The Company does not hold or issue derivatives for speculative or trading purposes. In addition, other nonfinancial assets and liabilities are measured at fair value in the financial statements on a nonrecurring basis. The fair values of these financial instruments and nonfinancial assets and liabilities measured at the reporting date are summarized as follows:
						Fair Value Measurements at Reporting Date Using
	Description	At March 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	$	152		$	-		$	152	$	-
						Fair Value Measurements at Reporting Date Using
	Description	At December 31, 2013			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	Fuel hedge contracts	$	332		$	-		$	332	$	-
	Foreign exchange contracts
	The Company has exposure 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 March 31, 2014 and December 31, 2013, 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 backlog.
	As of March 31, 2014, 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 February 2015. As of March 31, 2014, there were 4.4 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted fuel purchases through February 2015. Under these swap agreements, the Company will pay fixed prices ranging from $2.87 to $3.14 per gallon.
	At March 31, 2014, the fair value liability of the fuel hedge contracts was estimated to be $152 and is recorded in accrued expenses. At December 31, 2013, the fair value asset of the fuel hedge contracts was estimated to be $332 and is recorded in prepaid expenses and other current assets. The gain reclassified to earnings from changes in fair value of derivatives, net of cash settlements and taxes, for the three months ended March 31, 2014 was $46. The remaining gains and losses included in accumulated other comprehensive loss at March 31, 2014 will be reclassified into earnings over the next  eleven months, corresponding to the period during which the hedged fuel is expected to be utilized. 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 fair value of the fuel hedge contracts outstanding as of March 31, 2014 and December 31, 2013 is as follows:
				Fair Value at
				March 31,			December 31,
		Balance Sheet Location		2014			2013
	Asset derivatives:
	Derivatives designated as hedges
	Fuel hedge contracts	Prepaid expenses and other current assets		$	-		$	332
	Liability derivatives:
	Derivatives designated as hedges
	Fuel hedge contracts	Accrued expenses		$	152		$	-
	Accumulated other comprehensive loss
	Changes in the components of the accumulated balances of other comprehensive income are as follows:
				Three Months Ended
				March 31,
				2014			2013
	Cumulative translation adjustments—net of tax			$	-189		$	-6
	Derivatives:
	Reclassification of derivative losses (gains) to earnings—net of tax				-46			137
	Change in fair value of derivatives—net of tax				-243			-120
	Net unrealized (gain) loss on derivatives—net of tax				-289			17
	Total other comprehensive income (loss)			$	-478		$	11
	Adjustments reclassified from accumulated balances of other comprehensive income to earnings are as follows:
				Three Months Ended
				March 31,
		Statement of Operations Location		2014			2013
	Derivatives:
	Fuel hedge contracts	Costs of contract revenues		$	-77		$	228
		Income tax (provision) benefit			-31			91
				$	-46		$	137
	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. In January 2011, the Company issued $250,000 of 7.375% senior notes due February 1, 2019, which were outstanding at March 31, 2014. 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 $261,875 at March 31, 2014, which is a Level 1 fair value measurement as the senior notes value was obtained using quoted prices in active markets.

Commitments_And_Contingencies

Commitments And Contingencies	3 Months Ended
	Mar. 31, 2014
Commitments And Contingencies [Abstract]	'
Commitments And Contingencies	'
	7.   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. The Company also has outstanding bonds with Travelers Casualty and Surety Company of America. Bid bonds are generally obtained for a percentage of bid value and amounts outstanding typically range from $1,000 to $10,000. At March 31, 2014, the Company had outstanding performance bonds valued at approximately $843,298, of which $71,917 relates to projects accounted for in discontinued operations. The revenue value remaining in backlog related to the projects of continuing operations totaled approximately $318,793.
	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 March 19, 2013, the Company and three of its current and former executives were sued in a securities class action in the Northern District of Illinois captioned United Union of Roofers, Waterproofers & Allied Workers Local Union No. 8 v. Great Lakes Dredge & Dock Corporation et al., Case No. 1:13-cv-02115. The lawsuit, which was brought on behalf of all purchasers of the Company’s securities between August 7, 2012 and March 14, 2013, primarily alleges that the defendants made false and misleading statements regarding the recognition of revenue in the demolition segment and with regard to the Company’s internal control over financial reporting. This suit was filed following the Company’s announcement on March 14, 2013 that it would restate its second and third quarter 2012 financial statements. Two additional, similar lawsuits captioned Boozer v. Great Lakes Dredge & Dock Corporation et al., Case No. 1:13-cv-02339, and Connors v. Great Lakes Dredge & Dock Corporation et al., Case No. 1:13-cv-02450, were filed in the Northern District of Illinois on March 28, 2013, and April 2, 2013, respectively. These three actions were consolidated and recaptioned In re Great Lakes Dredge & Dock Corporation Securities Litigation, Case No. 1:13-cv-02115, on June 10, 2013. The plaintiffs filed an amended class action complaint on August 9, 2013, which the defendants moved to dismiss on October 8, 2013. The Company denies liability and intends to vigorously defend this action.
	On March 28, 2013, the Company was named as a nominal defendant, and its directors were named as defendants, in a shareholder derivative action in DuPage County Circuit Court in Illinois captioned Hammoud v. Berger et al., Case No. 2013CH001110. The lawsuit primarily alleges breaches of fiduciary duties related to allegedly false and misleading statements regarding the recognition of revenue in the demolition segment and with regard to the Company’s internal control over financial reporting, which exposed the Company to securities litigation. A second, similar lawsuit captioned The City of Haverhill Retirement System v. Leight et al., Case No. 1:13-cv-02470, was filed in the Northern District of Illinois on April 2, 2013 and was voluntarily dismissed on June 10, 2013. A third, similar lawsuit captioned St. Lucie County Fire District Firefighters Pension Trust Fund v. Leight et al., Case No. 13 CH 15483, was filed in Cook County Circuit Court in Illinois on July 8, 2013, and has since been transferred to DuPage County Circuit Court and consolidated with the Hammoud action. The Hammoud/St. Lucie plaintiffs have filed a consolidated amended complaint on December 9, 2013, but the action is otherwise stayed until there is a ruling on the motion to dismiss the securities class action. A fourth, similar lawsuit (that additionally named one current and one former executive as defendants) captioned Griffin v. Berger et al., Case No. 1:13-cv-04907, was filed in the Northern District of Illinois on July 9, 2013. The Griffin action is also stayed pending a ruling on the motion to dismiss the securities class action.
	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 on 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 in 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.
	As discussed in Note 8, on April 23, 2014, the Company completed the sale of NASDI, LLC (“NASDI”) and Yankee Environmental Services, LLC, 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 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. Should a claim be brought, the Company intends to defend this matter vigorously.
	In 2011, NASDI received a subpoena from a federal grand jury in the District of Massachusetts directing NASDI to furnish certain documents relating to certain projects performed by NASDI since January 2005. The Company conducted an internal investigation into this matter and has cooperated with the grand jury’s investigation. Based on the limited information known to the Company, the Company cannot predict the outcome of the investigation, the U.S. Attorney’s views of the issues being investigated, and any action the U.S. Attorney may take.
	On April 24, 2014, NASDI received a subpoena from a federal grand jury in the District of Massachusetts directing NASDI to furnish certain emails for the years 2004 to the present for the email accounts of certain former and present NASDI employees.  The Company is cooperating with the grand jury’s investigation. Based on the limited information known to the Company, the Company cannot predict the outcome of the investigation, the U.S. Attorney’s views of the issues being investigated, and any action the U.S. Attorney may take.

Business_Dispositions

Business Dispositions	3 Months Ended
	Mar. 31, 2014
Business Dispositions [Abstract]	'
Business Combinations And Reorganizations	'
	8.   Business dispositions
	On April 23, 2014, the Company entered into an agreement and completed the sale of NASDI, LLC and Yankee Environmental Services, LLC, its two subsidiaries that comprised the historical demolition business.  Under the terms of the agreement, the Company received cash 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, which is subject to change based upon the final terms of the sale, including subsequent adjustments to the purchase price related to additional proceeds.
	To the extent the Company incurs liabilities for exit costs, including severance, other employee benefits costs and operating lease obligations, the liabilities will be measured at fair value and recorded when incurred.
	The results of the businesses have been reported in discontinued operations as follows:
		Three Months Ended
		March 31,
		2014		2013
	Revenue	$	12,124	$	8,694
	Loss before income taxes from discontinued operations	$	-9,620	$	-7,901
	Income tax benefit		6,881		3,560
	Loss from discontinued operations, net of income taxes	$	-2,739	$	-4,341
	The major classes of assets and liabilities of businesses reported as discontinued operations are shown below:
		March 31,		December 31,
		2014		2013
	Assets:
	Accounts receivable - net	$	14,605	$	15,445
	Contract revenues in excess of billings		12,427		13,130
	Other current assets		4,037		14,825
	Property and equipment—net		9,189		8,765
	Other intangible assets —net		85		91
	Assets of discontinued operations	$	40,343	$	52,256
	Liabilities:
	Accounts payable	$	7,586	$	9,480
	Accrued expenses		6,466		4,091
	Reserve for loss on disposal		11,098		18,436
	Other current liabilities		1,431		486
	Other liabilities		707		1,212
	Liabilities of discontinued operations	$	27,288	$	33,705

Segment_Information

Segment Information	3 Months Ended
	Mar. 31, 2014
Segment Information [Abstract]	'
Segment Information	'
	9.   Segment information
	The Company and its subsidiaries currently operate in two reportable segments: dredging and environmental and 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 the periods presented is provided as follows:
		Three Months Ended
		March 31,
		2014		2013
	Dredging
	Contract revenues	$	161,960	$	173,959
	Operating income		7,429		19,000
	Environmental & remediation
	Contract revenues	$	12,730	$	6,194
	Operating loss		-4,544		-4,504
	Intersegment revenues	$	-308	$	-
	Total
	Contract revenues	$	174,382	$	180,153
	Operating income		2,885		14,496
	Foreign dredging revenue of $16,470 and $38,385 for the three months ended March 31, 2014 and 2013, respectively, was primarily attributable to work done in Brazil as well as for the Wheatstone LNG project in Western Australia.
	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.

Subsidiary_Guarantors

Subsidiary Guarantors	3 Months Ended
	Mar. 31, 2014
Subsidiary Guarantors [Abstract]	'
Subsidiary Guarantors	'
	10.   Subsidiary guarantors
	The Company’s long-term debt at March 31, 2014 includes $250,000 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 March 31, 2014 and December 31, 2013;
		(ii)	statements of operations and comprehensive income (loss) for the three months ended March 31, 2014 and 2013; and
		(iii)	statements of cash flows for the three months ended March 31, 2014 and 2013.
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF MARCH 31, 2014
	(In thousands)
	ASSETS	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	CURRENT ASSETS:
	Cash and cash equivalents	$	56,659		$	1,971		$	65		$	-		$	58,695
	Accounts receivable — net		65,507			-			-			-			65,507
	Receivables from affiliates		104,275			8,066			46,065			-158,406			-
	Contract revenues in excess of billings		88,168			4,893			-			-			93,061
	Inventories		34,707			-			-			-			34,707
	Prepaid expenses and other current assets		28,614			307			10,540			-			39,461
	Assets held for sale		29,647			11,599			-			-8,473			32,773
	Total current assets		407,577			26,836			56,670			-166,879			324,204
	PROPERTY AND EQUIPMENT—Net		356,979			7			-			-			356,986
	GOODWILL AND OTHER INTANGIBLE ASSETS—Net		81,047			-			-			-			81,047
	INVENTORIES — Noncurrent		36,707			-			-			-			36,707
	INVESTMENTS IN JOINT VENTURES		7,055			-			-			-			7,055
	INVESTMENTS IN SUBSIDIARIES		4,644			-			585,671			-590,315			-
	ASSETS HELD FOR SALE—Noncurrent		9,220			54			-			-			9,274
	OTHER		5,609			3			4,905			-			10,517
	TOTAL	$	908,838		$	26,900		$	647,246		$	-757,194		$	825,790
	LIABILITIES AND EQUITY
	CURRENT LIABILITIES:
	Accounts payable	$	108,459		$	640		$	436		$	-		$	109,535
	Payables to affiliates		124,689			24,101			9,616			-158,406			-
	Accrued expenses		26,536			16			5,699			-			32,251
	Billings in excess of contract revenues		4,961			-			-			-			4,961
	Liabilities held for sale		33,669			1,385			-			-8,473			26,581
	Total current liabilities		298,314			26,142			15,751			-166,879			173,328
	7 3/8% SENIOR NOTES		-			-			250,000			-			250,000
	REVOLVING CREDIT FACILITY		-			-			37,000			-			37,000
	DEFERRED INCOME TAXES		1,682			-			106,249			-			107,931
	LIABILITIES HELD FOR SALE—Noncurrent		707			-			-			-			707
	OTHER		18,578			-			546			-			19,124
	Total liabilities		319,281			26,142			409,546			-166,879			588,090
	Total Great Lakes Dredge & Dock Corporation Equity		589,557			758			237,700			-590,315			237,700
	NONCONTROLLING INTERESTS		-			-			-			-			-
	TOTAL EQUITY		589,557			758			237,700			-590,315			237,700
	TOTAL	$	908,838		$	26,900		$	647,246		$	-757,194		$	825,790
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF DECEMBER 31, 2013
	(In thousands)
	ASSETS	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	CURRENT ASSETS:
	Cash and cash equivalents	$	71,939		$	3,399		$	-		$	-		$	75,338
	Accounts receivable — net		95,476			1,039			-			-			96,515
	Receivables from affiliates		131,984			7,337			12,205			-151,526			-
	Contract revenues in excess of billings		63,591			3,841			-			-			67,432
	Inventories		32,500			-			-			-			32,500
	Prepaid expenses and other current assets		23,549			137			20,478			-			44,164
	Assets held for sale		41,763			11,877			-			-8,536			45,104
	Total current assets		460,802			27,630			32,683			-160,062			361,053
	PROPERTY AND EQUIPMENT—Net		345,612			8			-			-			345,620
	GOODWILL AND OTHER INTANGIBLE ASSETS—Net		81,302			-			-			-			81,302
	INVENTORIES — Noncurrent		38,496			-			-			-			38,496
INVESTMENTS IN JOINT VENTURES		8,256			-			-			-			8,256
INVESTMENTS IN SUBSIDIARIES		1,212			-			638,955			-640,167			-
ASSETS HELD FOR SALE—Noncurrent		8,796			60			-			-			8,856
OTHER		3,886			3			5,193			-20			9,062
TOTAL	$	948,362		$	27,701		$	676,831		$	-800,249		$	852,645
LIABILITIES AND EQUITY
CURRENT LIABILITIES:
Accounts payable	$	115,235		$	754		$	132		$	-		$	116,121
Payables to affiliates		96,270			24,862			30,394			-151,526			-
Accrued expenses		28,086			15			10,430			-			38,531
Billings in excess of contract revenues		6,754			-			-			-			6,754
Current portion of long term debt		-			-			-			-			-
Liabilities held for sale		38,158			2,871			-			-8,536			32,493
Total current liabilities		284,503			28,502			40,956			-160,062			193,899
7 3/8% SENIOR NOTES		-			-			250,000			-			250,000
REVOLVING CREDIT FACILITY		-			-			35,000			-			35,000
DEFERRED INCOME TAXES		-			-			108,531			-20			108,511
LIABILITIES HELD FOR SALE—Noncurrent		1,212			-			-			-			1,212
OTHER		21,679			-			243			-			21,922
Total liabilities		307,394			28,502			434,730			-160,082			610,544
Total Great Lakes Dredge & Dock Corporation Equity		640,968			-801			242,946			-640,167			242,946
NONCONTROLLING INTERESTS		-			-			-845			-			-845
TOTAL EQUITY		640,968			-801			242,101			-640,167			242,101
TOTAL	$	948,362		$	27,701		$	676,831		$	-800,249		$	852,645
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE THREE MONTHS ENDED MARCH 31, 2014
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	173,322		$	6,029		$	-		$	-4,969		$	174,382
Costs of contract revenues		-150,737			-7,707			-			4,969			-153,475
Gross profit		22,585			-1,678			-			-			20,907
OPERATING EXPENSES:
General and administrative expenses		17,870			-			-			-			17,870
Loss on sale of assets—net		152			-			-			-			152
Operating loss		4,563			-1,678			-			-			2,885
Interest expense—net		69			-129			-4,956			-			-5,016
Equity in earnings (loss) of subsidiaries		-1,143			-			3,505			-2,362			-
Equity in loss of joint ventures		-1,843			-			-			-			-1,843
Gain on foreign currency transactions—net		58			7			-			-			65
Income (loss) from continuing operations before income taxes		1,704			-1,800			-1,451			-2,362			-3,909
Income tax benefit		480			-			973			-			1,453
Income (loss) from continuing operations		2,184			-1,800			-478			-2,362			-2,456
Loss from discontinued operations, net of income taxes		-2,868			-1,024			-4,717			5,870			-2,739
Net loss		-684			-2,824			-5,195			3,508			-5,195
Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
Net loss attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	-684		$	-2,824		$	-5,195		$	3,508		$	-5,195
Comprehensive loss attributable to Great Lakes Dredge & Dock Corporation	$	-973		$	-3,013		$	-5,673		$	3,986		$	-5,673
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE THREE MONTHS ENDED MARCH 31, 2013
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	177,907		$	2,246		$	-		$	-			180,153
Costs of contract revenues		-147,283			-2,136			-			-			-149,419
Gross profit		30,624			110			-			-			30,734
OPERATING EXPENSES:
General and administrative expenses		16,236			-			-			-			16,236
Loss on sale of assets—net		2			-			-			-			2
Operating income (loss)		14,386			110			-			-			14,496
Interest expense—net		-19			-42			-5,672			-			-5,733
Equity in earnings (loss) of subsidiaries		-1,670			-			16,208			-14,538			-
Equity in loss of joint ventures		-591			-			-			-			-591
Loss on foreign currency transactions—net		36			-			-			-			36
Income from continuing operations before income taxes		12,142			68			10,536			-14,538			8,208
Income tax (provision) benefit		17			-			-3,473			-			-3,456
Income from continuing operations		12,159			68			7,063			-14,538			4,752
Income (loss) from discontinued operations, net of income taxes		-4,383			-5			-6,652			6,699			-4,341
Net income (loss)		7,776			63			411			-7,839			411
Net (income) loss attributable to noncontrolling interest		-			-			22			-			22
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	7,776		$	63		$	433		$	-7,839		$	433
Comprehensive income (loss) attributable to	$	7,793		$	57		$	444		$	-7,850		$	444
Great Lakes Dredge & Dock Corporation
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE THREE MONTHS ENDED MARCH 31, 2014
(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		$	11,746		$	-2,094		$	-1,007		$	-		$	8,645
Net cash flows provided by (used in) operating activities of discontinued operations			-1,611			-1,024			-			-			-2,635
Cash provided by (used in) operating activities			10,135			-3,118			-1,007			-			6,010
INVESTING ACTIVITIES:
Purchases of property and equipment			-21,631			-			-			-			-21,631
Proceeds from dispositions of property and equipment			64			-			-			-			64
Proceeds from (payments on) vendor performance obligations			-3,100			-			-			-			-3,100
Net change in accounts with affiliates			-722			-			-			722			-
Net cash flows used in investing activities of continuing operations			-25,389			-			-			722			-24,667
Net cash flows used in investing activities of discontinued operations			-26			-			-			-			-26
Cash used in investing activities			-25,415			-			-			722			-24,693
FINANCING ACTIVITIES:
Purchase of noncontrolling interest			-			-			-205			-			-205
Net change in accounts with affiliates			-			1,864			-1,142			-722			-
Exercise of options and purchases from employee stock plans			-			-			415			-			415
Excess income tax benefit from share-based compensation			-			-			4			-			4
Borrowings under revolving loans			-			-			40,000			-			40,000
Repayments of revolving loans			-			-			-38,000			-			-38,000
Net cash flows provided by financing activities of continuing operations			-			1,864			1,072			-722			2,214
Effect of foreign currency exchange rates on cash and cash equivalents			-			-174			-			-			-174
Net increase (decrease) in cash and cash equivalents			-15,280			-1,428			65			-			-16,643
Cash and cash equivalents at beginning of period			71,939			3,399			-			-			75,338
Cash and cash equivalents at end of period		$	56,659		$	1,971		$	65		$	-		$	58,695
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE THREE MONTHS ENDED MARCH 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		$	2,333		$	-1,295		$	-11,198		$	-		$	-10,160
Net cash flows provided by (used in) operating activities of discontinued operations			-3,067			-5			-			-			-3,072
Cash provided by (used in) operating activities			-734			-1,300			-11,198			-			-13,232
INVESTING ACTIVITIES:
Purchases of property and equipment			-15,364			-			-			-			-15,364
Proceeds from dispositions of property and equipment			58			-			-			-			58
Net change in accounts with affiliates			-1,722			-			-			1,722			-
Net cash flows used in investing activities of continuing operations			-17,028			-			-			1,722			-15,306
Net cash flows used in investing activities of discontinued operations			-150			-			-			-			-150
Cash used in investing activities			-17,178			-			-			1,722			-15,456
FINANCING ACTIVITIES:
Repayments of long term note payable			-			-			-10,547			-			-10,547
Taxes paid on settlement of vested share awards			-			-			-28			-			-28
Excess income tax benefit from share-based compensation			-			-			15			-			15
Net change in accounts with affiliates			-			1,184			538			-1,722			-
Borrowings under revolving loans			-			-			79,500			-			79,500
Repayments of revolving loans			-			-			-58,000			-			-58,000
Capital contributions			-			280			-280			-			-
Net cash flows provided by financing activities of continuing operations			-			1,464			11,198			-1,722			10,940
Net cash flows used in financing activities of discontinued operations			-25			-			-			-			-25
Cash provided by (used in) financing activities			-25			1,464			11,198			-1,722			10,915
Effect of foreign currency exchange rates on cash and cash equivalents			-			-24			-			-			-24
Net increase (decrease) in cash and cash equivalents			-17,937			140			-			-			-17,797
Cash and cash equivalents at beginning of period			24,273			167			-			-			24,440
Cash and cash equivalents at end of period		$	6,337		$	307		$	-		$	-		$	6,643

Earnings_per_share_Tables

Earnings per share (Tables)	3 Months Ended
	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Computations For Basic And Diluted Earnings Per Share	'
		Three Months Ended
	(shares in thousands)	March 31,
		2014		2013
	Income (loss) from continuing operations	$	-2,456	$	4,752
	Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation		-2,739		-4,319
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		-5,195		433
	Weighted-average common shares outstanding — basic		59,708		59,369
	Effect of stock options and restricted stock units		-		648
	Weighted-average common shares outstanding — diluted		59,708		60,017
	Earnings (loss) per share from continuing operations — basic	$	-0.04	$	0.08
	Earnings (loss) per share from continuing operations — diluted	$	-0.04	$	0.08

Accounts_Receivable_And_Contra1

Accounts Receivable And Contracts In Progress (Tables)	3 Months Ended
	Mar. 31, 2014
Accounts Receivable And Contracts In Progress [Abstract]	'
Schedule Of Accounts Receivable	'
		March 31,		December 31,
		2014		2013
	Completed contracts	$	15,248	$	17,361
	Contracts in progress		33,352		62,177
	Retainage		18,436		18,506
			67,036		98,044
	Allowance for doubtful accounts		-1,529		-1,529
	Total accounts receivable—net	$	65,507	$	96,515
Components Of Contracts In Progress	'
		March 31,		December 31,
		2014		2013
	Costs and earnings in excess of billings:
	Costs and earnings for contracts in progress	$	704,049	$	435,470
	Amounts billed		-616,628		-370,730
	Costs and earnings in excess of billings for contracts in progress		87,421		64,740
	Costs and earnings in excess of billings for completed contracts		5,640		2,692
	Total contract revenues in excess of billings	$	93,061	$	67,432
	Billings in excess of costs and earnings:
	Amounts billed	$	-177,450	$	-156,794
	Costs and earnings for contracts in progress		172,489		150,040
	Total billings in excess of contract revenues	$	-4,961	$	-6,754

Accrued_Expenses_Tables

Accrued Expenses (Tables)	3 Months Ended
	Mar. 31, 2014
Accrued Expenses [Abstract]	'
Accrued Expenses	'
		March 31,		December 31,
		2014		2013
	Payroll and employee benefits	$	10,171	$	13,664
	Insurance		9,426		8,649
	Income and other taxes		4,055		3,709
	Interest		3,308		8,066
	Percentage of completion adjustment		2,422		2,135
	Other		2,869		2,308
	Total accrued expenses	$	32,251	$	38,531

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	3 Months Ended
	Mar. 31, 2014
Fair Value Measurements [Abstract]	'
Adjustments Reclassified From Accumulated Other Comprehensive Income To Earnings	'
				Three Months Ended
				March 31,
		Statement of Operations Location		2014			2013
	Derivatives:
	Fuel hedge contracts	Costs of contract revenues		$	-77		$	228
		Income tax (provision) benefit			-31			91
				$	-46		$	137
Changes In Components Of Accumulated Other Comprehensive Income (Table) (Text Block)	'
				Three Months Ended
				March 31,
				2014			2013
	Cumulative translation adjustments—net of tax			$	-189		$	-6
	Derivatives:
	Reclassification of derivative losses (gains) to earnings—net of tax				-46			137
	Change in fair value of derivatives—net of tax				-243			-120
	Net unrealized (gain) loss on derivatives—net of tax				-289			17
	Total other comprehensive income (loss)			$	-478		$	11
Schedule of fair values of these financial instruments and nonfinancial assets and liabilities measured at the reporting (Table) (Text Block)	'
						Fair Value Measurements at Reporting Date Using
	Description	At March 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	$	152		$	-		$	152	$	-
						Fair Value Measurements at Reporting Date Using
	Description	At December 31, 2013			Quoted Prices in Active Markets for Identical Assets (Level 1)			Significant Other Observable Inputs (Level 2)		Significant Unobservable Inputs (Level 3)
	Fuel hedge contracts	$	332		$	-		$	332	$	-
Schedule Fair Value Measurements Balance Sheet Location	'
				Fair Value at
				March 31,			December 31,
		Balance Sheet Location		2014			2013
	Asset derivatives:
	Derivatives designated as hedges
	Fuel hedge contracts	Prepaid expenses and other current assets		$	-		$	332
	Liability derivatives:
	Derivatives designated as hedges
	Fuel hedge contracts	Accrued expenses		$	152		$	-

Business_Dispositions_Tables

Business Dispositions (Tables)	3 Months Ended
	Mar. 31, 2014
Business Dispositions [Abstract]	'
Schedule Of Discontinued Operation	'
		Three Months Ended
		March 31,
		2014		2013
	Revenue	$	12,124	$	8,694
	Loss before income taxes from discontinued operations	$	-9,620	$	-7,901
	Income tax benefit		6,881		3,560
	Loss from discontinued operations, net of income taxes	$	-2,739	$	-4,341
	The major classes of assets and liabilities of businesses reported as discontinued operations are shown below:
		March 31,		December 31,
		2014		2013
	Assets:
	Accounts receivable - net	$	14,605	$	15,445
	Contract revenues in excess of billings		12,427		13,130
	Other current assets		4,037		14,825
	Property and equipment—net		9,189		8,765
	Other intangible assets —net		85		91
	Assets of discontinued operations	$	40,343	$	52,256
	Liabilities:
	Accounts payable	$	7,586	$	9,480
	Accrued expenses		6,466		4,091
	Reserve for loss on disposal		11,098		18,436
	Other current liabilities		1,431		486
	Other liabilities		707		1,212
	Liabilities of discontinued operations	$	27,288	$	33,705

Segment_Information_Tables

Segment Information (Tables)	3 Months Ended
	Mar. 31, 2014
Segment Information [Abstract]	'
Segment Reporting By Segment	'
		Three Months Ended
		March 31,
		2014		2013
	Dredging
	Contract revenues	$	161,960	$	173,959
	Operating income		7,429		19,000
	Environmental & remediation
	Contract revenues	$	12,730	$	6,194
	Operating loss		-4,544		-4,504
	Intersegment revenues	$	-308	$	-
	Total
	Contract revenues	$	174,382	$	180,153
	Operating income		2,885		14,496

Subsidiary_Guarantors_Tables

Subsidiary Guarantors (Tables)	3 Months Ended																12 Months Ended
	Mar. 31, 2014																Dec. 31, 2013
Subsidiary Guarantors [Abstract]	'																'
Condensed Consolidating of Balance Sheet	'																'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES																GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEET																CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF MARCH 31, 2014																AS OF DECEMBER 31, 2013
	(In thousands)																(In thousands)
	ASSETS	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals			ASSETS	Subsidiary Guarantors		Non-Guarantor Subsidiaries		GLDD Corporation		Eliminations		Consolidated Totals
	CURRENT ASSETS:																CURRENT ASSETS:
	Cash and cash equivalents	$	56,659		$	1,971		$	65		$	-		$	58,695		Cash and cash equivalents	$	71,939	$	3,399	$	-	$	-	$	75,338
	Accounts receivable — net		65,507			-			-			-			65,507		Accounts receivable — net		95,476		1,039		-		-		96,515
	Receivables from affiliates		104,275			8,066			46,065			-158,406			-		Receivables from affiliates		131,984		7,337		12,205		-151,526		-
	Contract revenues in excess of billings		88,168			4,893			-			-			93,061		Contract revenues in excess of billings		63,591		3,841		-		-		67,432
	Inventories		34,707			-			-			-			34,707		Inventories		32,500		-		-		-		32,500
	Prepaid expenses and other current assets		28,614			307			10,540			-			39,461		Prepaid expenses and other current assets		23,549		137		20,478		-		44,164
	Assets held for sale		29,647			11,599			-			-8,473			32,773		Assets held for sale		41,763		11,877		-		-8,536		45,104
	Total current assets		407,577			26,836			56,670			-166,879			324,204		Total current assets		460,802		27,630		32,683		-160,062		361,053
	PROPERTY AND EQUIPMENT—Net		356,979			7			-			-			356,986		PROPERTY AND EQUIPMENT—Net		345,612		8		-		-		345,620
	GOODWILL AND OTHER INTANGIBLE ASSETS—Net		81,047			-			-			-			81,047		GOODWILL AND OTHER INTANGIBLE ASSETS—Net		81,302		-		-		-		81,302
	INVENTORIES — Noncurrent		36,707			-			-			-			36,707		INVENTORIES — Noncurrent		38,496		-		-		-		38,496
	INVESTMENTS IN JOINT VENTURES		7,055			-			-			-			7,055		INVESTMENTS IN JOINT VENTURES		8,256		-		-		-		8,256
	INVESTMENTS IN SUBSIDIARIES		4,644			-			585,671			-590,315			-		INVESTMENTS IN SUBSIDIARIES		1,212		-		638,955		-640,167		-
	ASSETS HELD FOR SALE—Noncurrent		9,220			54			-			-			9,274		ASSETS HELD FOR SALE—Noncurrent		8,796		60		-		-		8,856
	OTHER		5,609			3			4,905			-			10,517		OTHER		3,886		3		5,193		-20		9,062
	TOTAL	$	908,838		$	26,900		$	647,246		$	-757,194		$	825,790		TOTAL	$	948,362	$	27,701	$	676,831	$	-800,249	$	852,645
	LIABILITIES AND EQUITY																LIABILITIES AND EQUITY
	CURRENT LIABILITIES:																CURRENT LIABILITIES:
	Accounts payable	$	108,459		$	640		$	436		$	-		$	109,535		Accounts payable	$	115,235	$	754	$	132	$	-	$	116,121
	Payables to affiliates		124,689			24,101			9,616			-158,406			-		Payables to affiliates		96,270		24,862		30,394		-151,526		-
	Accrued expenses		26,536			16			5,699			-			32,251		Accrued expenses		28,086		15		10,430		-		38,531
	Billings in excess of contract revenues		4,961			-			-			-			4,961		Billings in excess of contract revenues		6,754		-		-		-		6,754
	Liabilities held for sale		33,669			1,385			-			-8,473			26,581		Current portion of long term debt		-		-		-		-		-
	Total current liabilities		298,314			26,142			15,751			-166,879			173,328		Liabilities held for sale		38,158		2,871		-		-8,536		32,493
																	Total current liabilities		284,503		28,502		40,956		-160,062		193,899
	7 3/8% SENIOR NOTES		-			-			250,000			-			250,000
	REVOLVING CREDIT FACILITY		-			-			37,000			-			37,000		7 3/8% SENIOR NOTES		-		-		250,000		-		250,000
	DEFERRED INCOME TAXES		1,682			-			106,249			-			107,931		REVOLVING CREDIT FACILITY		-		-		35,000		-		35,000
	LIABILITIES HELD FOR SALE—Noncurrent		707			-			-			-			707		DEFERRED INCOME TAXES		-		-		108,531		-20		108,511
	OTHER		18,578			-			546			-			19,124		LIABILITIES HELD FOR SALE—Noncurrent		1,212		-		-		-		1,212
	Total liabilities		319,281			26,142			409,546			-166,879			588,090		OTHER		21,679		-		243		-		21,922
																	Total liabilities		307,394		28,502		434,730		-160,082		610,544
	Total Great Lakes Dredge & Dock Corporation Equity		589,557			758			237,700			-590,315			237,700
	NONCONTROLLING INTERESTS		-			-			-			-			-		Total Great Lakes Dredge & Dock Corporation Equity		640,968		-801		242,946		-640,167		242,946
	TOTAL EQUITY		589,557			758			237,700			-590,315			237,700		NONCONTROLLING INTERESTS		-		-		-845		-		-845
	TOTAL	$	908,838		$	26,900		$	647,246		$	-757,194		$	825,790		TOTAL EQUITY		640,968		-801		242,101		-640,167		242,101
																	TOTAL	$	948,362	$	27,701	$	676,831	$	-800,249	$	852,645
Schedule Of Condensed Consolidating Operations And Comprehensive Income (Table) (TextBlock)	'																'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED MARCH 31, 2014
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	173,322		$	6,029		$	-		$	-4,969		$	174,382
	Costs of contract revenues		-150,737			-7,707			-			4,969			-153,475
	Gross profit		22,585			-1,678			-			-			20,907
	OPERATING EXPENSES:
	General and administrative expenses		17,870			-			-			-			17,870
	Loss on sale of assets—net		152			-			-			-			152
	Operating loss		4,563			-1,678			-			-			2,885
	Interest expense—net		69			-129			-4,956			-			-5,016
	Equity in earnings (loss) of subsidiaries		-1,143			-			3,505			-2,362			-
	Equity in loss of joint ventures		-1,843			-			-			-			-1,843
	Gain on foreign currency transactions—net		58			7			-			-			65
	Income (loss) from continuing operations before income taxes		1,704			-1,800			-1,451			-2,362			-3,909
	Income tax benefit		480			-			973			-			1,453
	Income (loss) from continuing operations		2,184			-1,800			-478			-2,362			-2,456
	Loss from discontinued operations, net of income taxes		-2,868			-1,024			-4,717			5,870			-2,739
	Net loss		-684			-2,824			-5,195			3,508			-5,195
	Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
	Net loss attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	-684		$	-2,824		$	-5,195		$	3,508		$	-5,195
	Comprehensive loss attributable to Great Lakes Dredge & Dock Corporation	$	-973		$	-3,013		$	-5,673		$	3,986		$	-5,673
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED MARCH 31, 2013
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	177,907		$	2,246		$	-		$	-			180,153
	Costs of contract revenues		-147,283			-2,136			-			-			-149,419
	Gross profit		30,624			110			-			-			30,734
	OPERATING EXPENSES:
	General and administrative expenses		16,236			-			-			-			16,236
	Loss on sale of assets—net		2			-			-			-			2
	Operating income (loss)		14,386			110			-			-			14,496
	Interest expense—net		-19			-42			-5,672			-			-5,733
	Equity in earnings (loss) of subsidiaries		-1,670			-			16,208			-14,538			-
	Equity in loss of joint ventures		-591			-			-			-			-591
	Loss on foreign currency transactions—net		36			-			-			-			36
	Income from continuing operations before income taxes		12,142			68			10,536			-14,538			8,208
	Income tax (provision) benefit		17			-			-3,473			-			-3,456
	Income from continuing operations		12,159			68			7,063			-14,538			4,752
	Income (loss) from discontinued operations, net of income taxes		-4,383			-5			-6,652			6,699			-4,341
	Net income (loss)		7,776			63			411			-7,839			411
	Net (income) loss attributable to noncontrolling interest		-			-			22			-			22
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	7,776		$	63		$	433		$	-7,839		$	433
	Comprehensive income (loss) attributable to	$	7,793		$	57		$	444		$	-7,850		$	444
	Great Lakes Dredge & Dock Corporation
Condensed Cash Flow Statement	'																'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED MARCH 31, 2013
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	177,907		$	2,246		$	-		$	-			180,153
	Costs of contract revenues		-147,283			-2,136			-			-			-149,419
	Gross profit		30,624			110			-			-			30,734
	OPERATING EXPENSES:
	General and administrative expenses		16,236			-			-			-			16,236
	Loss on sale of assets—net		2			-			-			-			2
	Operating income (loss)		14,386			110			-			-			14,496
	Interest expense—net		-19			-42			-5,672			-			-5,733
	Equity in earnings (loss) of subsidiaries		-1,670			-			16,208			-14,538			-
	Equity in loss of joint ventures		-591			-			-			-			-591
	Loss on foreign currency transactions—net		36			-			-			-			36
	Income from continuing operations before income taxes		12,142			68			10,536			-14,538			8,208
	Income tax (provision) benefit		17			-			-3,473			-			-3,456
	Income from continuing operations		12,159			68			7,063			-14,538			4,752
	Income (loss) from discontinued operations, net of income taxes		-4,383			-5			-6,652			6,699			-4,341
	Net income (loss)		7,776			63			411			-7,839			411
	Net (income) loss attributable to noncontrolling interest		-			-			22			-			22
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	7,776		$	63		$	433		$	-7,839		$	433
	Comprehensive income (loss) attributable to	$	7,793		$	57		$	444		$	-7,850		$	444
	Great Lakes Dredge & Dock Corporation
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE THREE MONTHS ENDED MARCH 31, 2014
	(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		$	11,746		$	-2,094		$	-1,007		$	-		$	8,645
	Net cash flows provided by (used in) operating activities of discontinued operations			-1,611			-1,024			-			-			-2,635
	Cash provided by (used in) operating activities			10,135			-3,118			-1,007			-			6,010
	INVESTING ACTIVITIES:
	Purchases of property and equipment			-21,631			-			-			-			-21,631
	Proceeds from dispositions of property and equipment			64			-			-			-			64
	Proceeds from (payments on) vendor performance obligations			-3,100			-			-			-			-3,100
	Net change in accounts with affiliates			-722			-			-			722			-
	Net cash flows used in investing activities of continuing operations			-25,389			-			-			722			-24,667
	Net cash flows used in investing activities of discontinued operations			-26			-			-			-			-26
	Cash used in investing activities			-25,415			-			-			722			-24,693
	FINANCING ACTIVITIES:
	Purchase of noncontrolling interest			-			-			-205			-			-205
	Net change in accounts with affiliates			-			1,864			-1,142			-722			-
	Exercise of options and purchases from employee stock plans			-			-			415			-			415
	Excess income tax benefit from share-based compensation			-			-			4			-			4
	Borrowings under revolving loans			-			-			40,000			-			40,000
	Repayments of revolving loans			-			-			-38,000			-			-38,000
	Net cash flows provided by financing activities of continuing operations			-			1,864			1,072			-722			2,214
	Effect of foreign currency exchange rates on cash and cash equivalents			-			-174			-			-			-174
	Net increase (decrease) in cash and cash equivalents			-15,280			-1,428			65			-			-16,643
	Cash and cash equivalents at beginning of period			71,939			3,399			-			-			75,338
	Cash and cash equivalents at end of period		$	56,659		$	1,971		$	65		$	-		$	58,695
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE THREE MONTHS ENDED MARCH 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		$	2,333		$	-1,295		$	-11,198		$	-		$	-10,160
	Net cash flows provided by (used in) operating activities of discontinued operations			-3,067			-5			-			-			-3,072
	Cash provided by (used in) operating activities			-734			-1,300			-11,198			-			-13,232
INVESTING ACTIVITIES:
Purchases of property and equipment			-15,364			-			-			-			-15,364
Proceeds from dispositions of property and equipment			58			-			-			-			58
Net change in accounts with affiliates			-1,722			-			-			1,722			-
Net cash flows used in investing activities of continuing operations			-17,028			-			-			1,722			-15,306
Net cash flows used in investing activities of discontinued operations			-150			-			-			-			-150
Cash used in investing activities			-17,178			-			-			1,722			-15,456
FINANCING ACTIVITIES:
Repayments of long term note payable			-			-			-10,547			-			-10,547
Taxes paid on settlement of vested share awards			-			-			-28			-			-28
Excess income tax benefit from share-based compensation			-			-			15			-			15
Net change in accounts with affiliates			-			1,184			538			-1,722			-
Borrowings under revolving loans			-			-			79,500			-			79,500
Repayments of revolving loans			-			-			-58,000			-			-58,000
Capital contributions			-			280			-280			-			-
Net cash flows provided by financing activities of continuing operations			-			1,464			11,198			-1,722			10,940
Net cash flows used in financing activities of discontinued operations			-25			-			-			-			-25
Cash provided by (used in) financing activities			-25			1,464			11,198			-1,722			10,915
Effect of foreign currency exchange rates on cash and cash equivalents			-			-24			-			-			-24
Net increase (decrease) in cash and cash equivalents			-17,937			140			-			-			-17,797
Cash and cash equivalents at beginning of period			24,273			167			-			-			24,440
Cash and cash equivalents at end of period		$	6,337		$	307		$	-		$	-		$	6,643

Basis_of_presentation_Narrativ

Basis of presentation (Narrative) (Details)	3 Months Ended	36 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Dec. 31, 2011	Dec. 31, 2011
	segment	Maximum [Member]	Minimum [Member]
Nature Of Business And Summary Of Significant Accounting Policies [Line Items]	'	'	'
Average equipment-related costs of total costs of contract revenue	'	23.00%	22.00%
Number of reportable segments	2	'	'
Number of Operating Segments	4	'	'
Shares excluded from computation of diluted earnings per share	0	'	'

Earnings_Per_Share_Estimated_U

Earnings Per Share (Estimated Useful Lives By Class Of Assets) (Narrative) (Detail)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014
Earnings Per Share [Abstract]	'
Potentially dilutive stock options and restricted stock units	789

Earnings_Per_Share_Computation

Earnings Per Share (Computations For Basic And Diluted Earnings Per Share) (Details) (USD $)	3 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Income (loss) from continuing operations	($2,456)	$4,752
Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation	-2,739	-4,319
Net income attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-5,195	433
Weighted-average common shares outstanding - basic	59,708	59,369
Effect of stock options and restricted stock units	'	648
Weighted-average common shares outstanding - diluted	59,708	60,017
Basic earnings (loss) per share attributable to continuing operations	($0.04)	$0.08
Diluted earnings (loss) per share attributable to continuing operations	($0.04)	$0.08
GLDD Corporation [Member]	'	'
Income (loss) from continuing operations	-478	7,063
Net income attributable to common stockholders of Great Lakes Dredge & Dock Corporation	($5,195)	$433

Accounts_Receivable_And_Contra2

Accounts Receivable And Contracts In Progress (Schedule Of Accounts Receivable) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Receivable [Line Items]	'	'
Retainage	$18,436	$18,506
Accounts Receivable, Gross	67,036	98,044
Allowance for doubtful accounts	-1,529	-1,529
Total accounts receivable-net	65,507	96,515
Current portion of accounts receivable-net	65,507	96,515
Completed Contracts [Member]	'	'
Accounts Receivable [Line Items]	'	'
Contracts	15,248	17,361
Contracts In Progress [Member]	'	'
Accounts Receivable [Line Items]	'	'
Contracts	$33,352	$62,177

Accounts_Receivable_And_Contra3

Accounts Receivable And Contracts In Progress (Components Of Contracts In Progress) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Costs and earnings in excess of billings for contracts in progress	$87,421	$64,740
Costs and earnings in excess of billings for completed contracts	5,640	2,692
Total contract revenues in excess of billings	93,061	67,432
Total billings in excess of contract revenues	-4,961	-6,754
Costs And Earnings In Excess Of Billings [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Costs and earnings for contracts in progress	704,049	435,470
Amounts billed	616,628	370,730
Billings In Excess Of Costs And Earnings [Member]	'	'
Accounts, Notes, Loans and Financing Receivable [Line Items]	'	'
Billings in excess of costs and earnings, Amounts billed	-177,450	-156,794
Billings in excess of costs and earnings, Costs and earnings for contracts in progress	$172,489	$150,040

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Expenses [Abstract]	'	'
Payroll and employee benefits	$10,171	$13,664
Insurance	9,426	8,649
Income and other taxes	4,055	3,709
Interest	3,308	8,066
Percentage of completion adjustment	2,422	2,135
Other	2,869	2,308
Total accrued expenses	$32,251	$38,531

Longterm_Debt_Narrative_Detail

Long-term Debt (Narrative) (Details) (USD $)

3 Months Ended

12 Months Ended

3 Months Ended

3 Months Ended

3 Months Ended

Mar. 31, 2014

Mar. 31, 2013

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Jun. 04, 2012

Mar. 31, 2014

Jun. 04, 2012

Jun. 04, 2012

Jun. 04, 2012

Mar. 31, 2014

Dec. 31, 2013

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

Mar. 31, 2014

item

Senior Notes [Member]

Foreign Line of Credit [Member]

Standby Letters of Credit [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Multicurrency [Member]

Swingline Loans [Member]

GLDD Corporation [Member]

GLDD Corporation [Member]

Maximum [Member]

Maximum [Member]

Minimum [Member]

Minimum [Member]

LIBOR Rate [Member]

Base Rate [Member]

LIBOR Rate [Member]

Base Rate [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Revolving Credit Facility [Member]

Debt Instrument [Line Items]

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Line of credit facility, maximum borrowing capacity

'

'

'

'

'

$125,000,000

'

$175,000,000

$50,000,000

$10,000,000

'

'

'

'

'

'

Line of Credit Facility, Amount Outstanding

37,000,000

'

35,000,000

'

'

'

'

'

'

'

37,000,000

35,000,000

'

'

'

'

Line of credit facility optional increase capacity

'

'

'

'

'

'

'

50,000,000

'

'

'

'

'

'

'

'

Revolving credit facility, interest rate description

'

'

'

'

'

'

'Depending on the Company's consolidated leverage ratio (as defined in the Credit Agreement), borrowings under the revolving credit facility will bear interest at the option of the Company of 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.

'

'

'

'

'

'

'

'

'

Net Leverage Ratio

4.5

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Debt Instrument, Basis Spread on Variable Rate

'

'

'

'

'

'

'

'

'

'

'

'

2.50%

1.50%

1.50%

0.50%

Fixed Charge Coverage Ratio

125.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Total Leverage Ratio

'

'

375.00%

'

'

'

'

'

'

'

'

'

'

'

'

'

Revolving credit facility, basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

'

'

2.50%

1.50%

1.50%

0.50%

Letters of credit outstanding

90,781,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage Of Debt Instrument Issued At Face Value

'

'

'

7.38%

'

'

'

'

'

'

'

'

'

'

'

'

Letter of credit remaining borrowing capacity

47,219,000

'

'

'

24,000,000

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, face amount

'

'

'

250,000

'

'

'

'

'

'

'

'

'

'

'

'

Amortization of deferred financing fees

$288,000

$288,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013	Jan. 31, 2011
Derivative underlying hedge percent	80.00%	'	'	'
Derivative, Nonmonetary Notional Amount	4.4	'	'	'
Senior Notes	$250,000,000	'	$250,000,000	$250,000,000
Reclassification of derivative losses to earnings-net of tax	-46,000	137,000	'	'
Fair value hedge liabilities	152,000	'	332,000	'
Senior notes interest rate	7.38%	'	'	7.38%
Maximum [Member]	'	'	'	'
Fixed price range	3.14	'	'	'
Minimum [Member]	'	'	'	'
Fixed price range	2.87	'	'	'
Senior Notes [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'	'
Senior Notes	$261,875,000	'	'	'

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements at Reporting Date Using) (Details) (Fuel Hedge Contracts [Member], USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets, fair value disclosure	'	$332
Liabilities, fair value disclosure	152	'
Fair Value, Inputs, Level 2 [Member]	'	'
Assets, fair value disclosure	'	332
Liabilities, fair value disclosure	$152	'

Fair_Value_Measurements_Accumu

Fair Value Measurements (Accumulated other comprehensive loss) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014		Mar. 31, 2013
Derivatives, Fair Value [Line Items]	'		'
Cumulative translation adjustments-net of tax	($189)		($6)
Reclassification of derivative losses (gains) to earnings-net of tax	-46		137
Total other comprehensive income (loss)	-243		-120
Net unrealized (gain) loss on derivatives-net of tax (2)	-289	[1]	17	[1]
Other comprehensive income (loss)-net of tax	-478	[2]	11	[2]
Costs of contract revenues	153,475		149,419
Income tax provision	-1,453		3,456
Net income	-5,195		411
GLDD Corporation [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Income tax provision	-973		3,473
Net income	-5,195		411
Fuel Hedge Contracts [Member]	'		'
Derivatives, Fair Value [Line Items]	'		'
Costs of contract revenues	-77		228
Income tax provision	-31		91
Net income	($46)		$137
[1]	Net of income tax (expense) benefit of $(194) and $11 for the three months ended March 31, 2014 and 2013, respectively.
[2]

Fair_Value_Measurements_Balanc

Fair Value Measurements (Balance Sheet Location) (Details) (Designated as Hedging Instrument [Member], USD $)	Dec. 31, 2013	Mar. 31, 2014
In Thousands, unless otherwise specified	Other Current Assets [Member]	Accrued Liabilities [Member]
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value, gross asset	$332	'
Derivative asset, fair value, gross liability	'	$152

Fair_Value_Measurements_Adjust

Fair Value Measurements (Adjustments reclassified from accumulated balances other comprohensive Income to earning) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Costs of contract revenues	$153,475	$149,419
Income tax provision	-1,453	3,456
Net income	-5,195	411
Fuel Hedge Contracts [Member]	'	'
Costs of contract revenues	-77	228
Income tax provision	-31	91
Net income	-46	137
GLDD Corporation [Member]	'	'
Income tax provision	-973	3,473
Net income	($5,195)	$411

Commitments_And_Contingencies_

Commitments And Contingencies (Details) (USD $)	12 Months Ended							3 Months Ended
	Dec. 31, 2012	Mar. 31, 2014	Dec. 31, 2013	Jan. 31, 2011	Mar. 31, 2014	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2014	Mar. 31, 2014
					Projects Accounted For Discontinued Operations [Member]	GLDD Corporation [Member]	GLDD Corporation [Member]	Maximum [Member]	Minimum [Member]
Commitments And Contingencies [Line Items]	'	'	'	'	'	'	'	'	'
Letters of credit outstanding	'	$90,781,000	'	'	'	'	'	'	'
Letter of credit remaining borrowing capacity	'	47,219,000	'	'	'	'	'	'	'
Senior notes interest rate	'	7.38%	'	7.38%	'	'	'	'	'
Bids bond range	'	'	'	'	'	'	'	10,000,000	1,000,000
Outstanding performance bonds	'	843,298,000	'	'	71,917,000	'	'	'	'
Revenue value remaining from outstanding performance bonds	'	318,793,000	'	'	'	'	'	'	'
Warranty periods	'	'	'	'	'	'	'	'3 years	'1 year
Senior Notes	'	250,000,000	250,000,000	250,000,000	'	250,000,000	250,000,000	'	'
Proceeds from Lines of Credit	13,600,000	'	'	'	'	'	'	'	'
Gain (Loss) Related to Litigation Settlement	10,500,000	'	'	'	'	'	'	'	'
Funds remitted	$3,100,000	'	'	'	'	'	'	'	'

Business_Combinations_And_Disp

Business Combinations And Dispositions (Results Of Discontinued Operations) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Business Dispositions [Abstract]	'	'
Revenue	$12,124	$8,694
Loss before income taxes from discontinued operations	-9,620	-7,901
Income tax benefit	6,881	3,560
Loss from discontinued operations, net of income taxes	($2,739)	($4,341)

Business_Combinations_And_Reor

Business Combinations And Reorganizations (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Assets, Current [Abstract]	'	'
Accounts receivable - net from discontinued operations	$14,605	$15,445
Assets and liabilities of businesses reported as discontinued operations for contracts revenues in excess of billing	12,427	13,130
Other current assets	4,037	14,825
Property and equipment-net	9,189	8,765
Other intangible assets -net	85	91
Assets of discontinued operations	40,343	52,256
Accounts payable from discontinued operations	7,586	9,480
Accrued expenses	6,466	4,091
Reserve for loss on disposal from discontinued operations	11,098	18,436
Other current liabilities from discontinued operations	1,431	486
Other liabilities from discontinued operations	707	1,212
Liabilities of discontinued operations	$27,288	$33,705

Segment_Information_Narrative_

Segment Information (Narrative) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
	segment
Segment Reporting Information [Line Items]	'	'
Contract revenues	$174,382	$180,153
Number of reportable segments	2	'
Dredging [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Contract revenues	161,960	173,959
Number of reportable segments	2	'
Demolition [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Contract revenues	12,730	6,194
Foreign [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Contract revenues	16,470	38,385
Intersegment Revenues [Member]	'	'
Segment Reporting Information [Line Items]	'	'
Contract revenues	($308)	'

Segment_Information_Segment_Re

Segment Information (Segment Reporting By Segment) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013	Dec. 31, 2013
	segment
Segment Reporting Information [Line Items]	'	'	'
Contract revenues	$174,382	$180,153	'
Operating income (loss)	2,885	14,496	'
Depreciation and amortization	10,885	11,451	'
Total assets	825,790	'	852,645
Property and equipment - net	356,986	'	345,620
Investment in joint ventures	7,055	'	8,256
Number of Reportable Segments	2	'	'
GLDD Corporation [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Total assets	647,246	'	676,831
Dredging [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Contract revenues	161,960	173,959	'
Operating income (loss)	7,429	19,000	'
Number of Reportable Segments	2	'	'
Demolition [Member]	'	'	'
Segment Reporting Information [Line Items]	'	'	'
Contract revenues	12,730	6,194	'
Operating income (loss)	($4,544)	($4,504)	'

Subsidiary_Guarantors_Narrativ

Subsidiary Guarantors (Narrative) (Details) (USD $)	3 Months Ended
	Mar. 31, 2014	Dec. 31, 2013	Jan. 31, 2011
Senior Notes	$250,000,000	$250,000,000	$250,000,000
Senior notes interest rate	7.38%	'	7.38%
Owned Domestic Subsidiaries Percent	100.00%	'	'
GLDD Corporation [Member]	'	'	'
Senior Notes	$250,000,000	$250,000,000	'

Subsidiary_Guarantors_Condense

Subsidiary Guarantors (Condensed Consolidated Balance Sheets) (Details) (USD $)	Mar. 31, 2014	Dec. 31, 2013	Mar. 31, 2013	Dec. 31, 2012	Jan. 31, 2011
ASSETS	'	'	'	'	'
Cash and cash equivalents	$58,695,000	$75,338,000	$6,643,000	$24,440,000	'
Accounts receivable-net	65,507,000	96,515,000	'	'	'
Contract revenues in excess of billings	93,061,000	67,432,000	'	'	'
Inventories	34,707,000	32,500,000	'	'	'
Prepaid Expense and Other Assets, Current	39,461,000	44,164,000	'	'	'
Assets Held-for-sale, Current	32,773,000	45,104,000	'	'	'
Total current assets	324,204,000	361,053,000	'	'	'
PROPERTY AND EQUIPMENT-Net	356,986,000	345,620,000	'	'	'
GOODWILL AND OTHER INTANGIBLE	81,047,000	81,302,000	'	'	'
INVENTORIES-Noncurrent	36,707,000	38,496,000	'	'	'
INVESTMENTS IN JOINT VENTURES	7,055,000	8,256,000	'	'	'
ASSETS HELD FOR SALE-Noncurrent	9,274,000	8,856,000	'	'	'
OTHER	10,517,000	9,062,000	'	'	'
TOTAL	825,790,000	852,645,000	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	109,535,000	116,121,000	'	'	'
Accrued expenses	32,251,000	38,531,000	'	'	'
Billings in excess of contract revenues	4,961,000	6,754,000	'	'	'
Liabilities held for sale	26,581,000	32,493,000	'	'	'
Total current liabilities	173,328,000	193,899,000	'	'	'
7 3/8% SENIOR NOTES	250,000,000	250,000,000	'	'	250,000,000
REVOLVING CREDIT FACILITY	37,000,000	35,000,000	'	'	'
DEFERRED INCOME TAXES	107,931,000	108,511,000	'	'	'
Liabilities held for sale, noncurrent	707,000	1,212,000	'	'	'
OTHER	19,124,000	21,922,000	'	'	'
Total liabilities	588,090,000	610,544,000	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	237,700,000	242,946,000	'	'	'
NONCONTROLLING INTERESTS	'	-845,000	'	'	'
Total equity	237,700,000	242,101,000	274,585,000	273,425,000	'
TOTAL	825,790,000	852,645,000	'	'	'
Subsidiary Guarantors [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	56,659,000	71,939,000	6,337,000	24,273,000	'
Accounts receivable-net	65,507,000	95,476,000	'	'	'
Receivables from affiliates	104,275,000	131,984,000	'	'	'
Contract revenues in excess of billings	88,168,000	63,591,000	'	'	'
Inventories	34,707,000	32,500,000	'	'	'
Prepaid Expense and Other Assets, Current	28,614,000	23,549,000	'	'	'
Assets Held-for-sale, Current	29,647,000	41,763,000	'	'	'
Total current assets	407,577,000	460,802,000	'	'	'
PROPERTY AND EQUIPMENT-Net	356,979,000	345,612,000	'	'	'
GOODWILL AND OTHER INTANGIBLE	81,047,000	81,302,000	'	'	'
INVENTORIES-Noncurrent	36,707,000	38,496,000	'	'	'
INVESTMENTS IN JOINT VENTURES	7,055,000	8,256,000	'	'	'
INVESTMENTS IN SUBSIDIARIES	4,644,000	1,212,000	'	'	'
ASSETS HELD FOR SALE-Noncurrent	9,220,000	8,796,000	'	'	'
OTHER	5,609,000	3,886,000	'	'	'
TOTAL	908,838,000	948,362,000	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	108,459,000	115,235,000	'	'	'
Payables to affiliates	124,689,000	96,270,000	'	'	'
Accrued expenses	26,536,000	28,086,000	'	'	'
Billings in excess of contract revenues	4,961,000	6,754,000	'	'	'
Liabilities held for sale	33,669,000	38,158,000	'	'	'
Total current liabilities	298,314,000	284,503,000	'	'	'
DEFERRED INCOME TAXES	1,682,000	'	'	'	'
Liabilities held for sale, noncurrent	707,000	1,212,000	'	'	'
OTHER	18,578,000	21,679,000	'	'	'
Total liabilities	319,281,000	307,394,000	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	589,557,000	640,968,000	'	'	'
Total equity	589,557,000	640,968,000	'	'	'
TOTAL	908,838,000	948,362,000	'	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	1,971,000	3,399,000	307,000	167,000	'
Accounts receivable-net	'	1,039,000	'	'	'
Receivables from affiliates	8,066,000	7,337,000	'	'	'
Contract revenues in excess of billings	4,893,000	3,841,000	'	'	'
Prepaid Expense and Other Assets, Current	307,000	137,000	'	'	'
Assets Held-for-sale, Current	11,599,000	11,877,000	'	'	'
Total current assets	26,836,000	27,630,000	'	'	'
PROPERTY AND EQUIPMENT-Net	7,000	8,000	'	'	'
ASSETS HELD FOR SALE-Noncurrent	54,000	60,000	'	'	'
OTHER	3,000	3,000	'	'	'
TOTAL	26,900,000	27,701,000	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	640,000	754,000	'	'	'
Payables to affiliates	24,101,000	24,862,000	'	'	'
Accrued expenses	16,000	15,000	'	'	'
Liabilities held for sale	1,385,000	2,871,000	'	'	'
Total current liabilities	26,142,000	28,502,000	'	'	'
Total liabilities	26,142,000	28,502,000	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	758,000	-801,000	'	'	'
Total equity	758,000	-801,000	'	'	'
TOTAL	26,900,000	27,701,000	'	'	'
GLDD Corporation [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	65,000	'	'	'	'
Receivables from affiliates	46,065,000	12,205,000	'	'	'
Prepaid Expense and Other Assets, Current	10,540,000	20,478,000	'	'	'
Total current assets	56,670,000	32,683,000	'	'	'
INVESTMENTS IN SUBSIDIARIES	585,671,000	638,955,000	'	'	'
OTHER	4,905,000	5,193,000	'	'	'
TOTAL	647,246,000	676,831,000	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	436,000	132,000	'	'	'
Payables to affiliates	9,616,000	30,394,000	'	'	'
Accrued expenses	5,699,000	10,430,000	'	'	'
Total current liabilities	15,751,000	40,956,000	'	'	'
7 3/8% SENIOR NOTES	250,000,000	250,000,000	'	'	'
REVOLVING CREDIT FACILITY	37,000,000	35,000,000	'	'	'
DEFERRED INCOME TAXES	106,249,000	108,531,000	'	'	'
OTHER	546,000	243,000	'	'	'
Total liabilities	409,546,000	434,730,000	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	237,700,000	242,946,000	'	'	'
NONCONTROLLING INTERESTS	'	-845,000	'	'	'
Total equity	237,700,000	242,101,000	'	'	'
TOTAL	647,246,000	676,831,000	'	'	'
Eliminations [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Receivables from affiliates	-158,406,000	-151,526,000	'	'	'
Assets Held-for-sale, Current	-8,473,000	-8,536,000	'	'	'
Total current assets	-166,879,000	-160,062,000	'	'	'
INVESTMENTS IN SUBSIDIARIES	-590,315,000	-640,167,000	'	'	'
OTHER	'	-20,000	'	'	'
TOTAL	-757,194,000	-800,249,000	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Payables to affiliates	-158,406,000	-151,526,000	'	'	'
Liabilities held for sale	-8,473,000	-8,536,000	'	'	'
Total current liabilities	-166,879,000	-160,062,000	'	'	'
DEFERRED INCOME TAXES	'	-20,000	'	'	'
Total liabilities	-166,879,000	-160,082,000	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	-590,315,000	-640,167,000	'	'	'
Total equity	-590,315,000	-640,167,000	'	'	'
TOTAL	($757,194,000)	($800,249,000)	'	'	'

Subsidiary_Guarantors_Condense1

Subsidiary Guarantors (Condensed Consolidated Statement Operations And Comprehensive Income) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
Condensed Financial Statements, Captions [Line Items]	'	'
Contract revenues	$174,382	$180,153
Costs of contract revenues	-153,475	-149,419
GROSS PROFIT	20,907	30,734
General and administrative expenses	17,870	16,236
Gain on sale of assets-net	152	2
Total operating income	2,885	14,496
Interest expense-net	-5,016	-5,733
Equity in loss of joint ventures	-1,843	-591
Loss on foreign currency transactions-net	65	36
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	-3,909	'
Income (loss) from continuing operations before income taxes	-3,909	8,208
Income tax (provision) benefit	1,453	-3,456
Income (loss) from continuing operations	-2,456	4,752
Loss from discontinued operations, net of income taxes	-2,739	-4,341
NET INCOME	-5,195	411
Net (income) loss attributable to noncontrolling interests	'	22
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-5,195	433
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-5,673	444
Subsidiary Guarantors [Member]	'	'
Condensed Financial Statements, Captions [Line Items]	'	'
Contract revenues	173,322	177,907
Costs of contract revenues	-150,737	-147,283
GROSS PROFIT	22,585	30,624
General and administrative expenses	17,870	16,236
Gain on sale of assets-net	152	2
Total operating income	4,563	14,386
Interest expense-net	69	-19
Equity in earnings (loss) of subsidiaries	-1,143	-1,670
Equity in loss of joint ventures	-1,843	-591
Loss on foreign currency transactions-net	58	36
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	1,704	'
Income (loss) from continuing operations before income taxes	'	12,142
Income tax (provision) benefit	480	17
Income (loss) from continuing operations	2,184	12,159
Loss from discontinued operations, net of income taxes	-2,868	-4,383
NET INCOME	-684	7,776
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-684	7,776
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-973	7,793
Non-Guarantor Subsidiaries [Member]	'	'
Condensed Financial Statements, Captions [Line Items]	'	'
Contract revenues	6,029	2,246
Costs of contract revenues	-7,707	-2,136
GROSS PROFIT	-1,678	110
Total operating income	-1,678	110
Interest expense-net	-129	-42
Loss on foreign currency transactions-net	7	'
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	-1,800	'
Income (loss) from continuing operations before income taxes	'	68
Income (loss) from continuing operations	-1,800	68
Loss from discontinued operations, net of income taxes	-1,024	-5
NET INCOME	-2,824	63
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-2,824	63
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-3,013	57
GLDD Corporation [Member]	'	'
Condensed Financial Statements, Captions [Line Items]	'	'
Interest expense-net	-4,956	-5,672
Equity in earnings (loss) of subsidiaries	3,505	16,208
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	-1,451	'
Income (loss) from continuing operations before income taxes	'	10,536
Income tax (provision) benefit	973	-3,473
Income (loss) from continuing operations	-478	7,063
Loss from discontinued operations, net of income taxes	-4,717	-6,652
NET INCOME	-5,195	411
Net (income) loss attributable to noncontrolling interests	'	22
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-5,195	433
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-5,673	444
Eliminations [Member]	'	'
Condensed Financial Statements, Captions [Line Items]	'	'
Contract revenues	-4,969	'
Costs of contract revenues	4,969	'
Equity in earnings (loss) of subsidiaries	-2,362	-14,538
Income (Loss) from Continuing Operations, Including Portion Attributable to Noncontrolling Interest	-2,362	'
Income (loss) from continuing operations before income taxes	'	-14,538
Income (loss) from continuing operations	-2,362	-14,538
Loss from discontinued operations, net of income taxes	5,870	6,699
NET INCOME	3,508	-7,839
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	3,508	-7,839
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	$3,986	($7,850)

Subsidiary_Guarantors_Condense2

Subsidiary Guarantors (Condensed Consolidated of Cash Flow) (Details) (USD $)	3 Months Ended
In Thousands, unless otherwise specified	Mar. 31, 2014	Mar. 31, 2013
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	$8,645	($10,160)
Net cash flows used in operating activities of discontinued operations	-2,635	-3,072
Cash provided by (used in) operating activities	6,010	-13,232
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-21,631	-15,364
Proceeds from dispositions of property and equipment	64	58
Proceeds from vendor performance obligations	-3,100	'
Net cash flows used in investing activities of continuing operations	-24,667	-15,306
Net cash flows used in investing activities of discontinued operations	-26	-150
Cash used in investing activities	-24,693	-15,456
FINANCING ACTIVITIES:	'	'
Purchase of noncontrolling interest	-205	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	'	-28
Exercise of stock	415	'
Excess income tax benefit from share-based compensation	4	15
Borrowings under revolving loans	40,000	79,500
Repayments of revolving loans	-38,000	-58,000
Net cash flows provided by financing activities of continuing operations	2,214	10,940
Net cash flows used in financing activities of discontinued operations	'	-25
Cash provided by financing activities	2,214	10,915
Effect of foreign currency exchange rates on cash and cash equivalents	-174	-24
Net decrease in cash and cash equivalents	-16,643	-17,797
Cash and cash equivalents at beginning of period	75,338	24,440
Cash and cash equivalents at end of period	58,695	6,643
Subsidiary Guarantors [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	11,746	2,333
Net cash flows used in operating activities of discontinued operations	-1,611	-3,067
Cash provided by (used in) operating activities	10,135	-734
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-21,631	-15,364
Proceeds from dispositions of property and equipment	64	58
Net change in accounts with affiliates	-722	-1,722
Proceeds from vendor performance obligations	-3,100	'
Net cash flows used in investing activities of continuing operations	-25,389	-17,028
Net cash flows used in investing activities of discontinued operations	-26	-150
Cash used in investing activities	-25,415	-17,178
FINANCING ACTIVITIES:	'	'
Net cash flows used in financing activities of discontinued operations	'	-25
Cash provided by financing activities	'	-25
Net decrease in cash and cash equivalents	-15,280	-17,937
Cash and cash equivalents at beginning of period	71,939	24,273
Cash and cash equivalents at end of period	56,659	6,337
Non-Guarantor Subsidiaries [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	-2,094	-1,295
Net cash flows used in operating activities of discontinued operations	-1,024	-5
Cash provided by (used in) operating activities	-3,118	-1,300
FINANCING ACTIVITIES:	'	'
Net change in accounts with affiliates, in finance activities	1,864	1,184
Capital contributions	'	280
Net cash flows provided by financing activities of continuing operations	1,864	1,464
Cash provided by financing activities	'	1,464
Effect of foreign currency exchange rates on cash and cash equivalents	-174	-24
Net decrease in cash and cash equivalents	-1,428	140
Cash and cash equivalents at beginning of period	3,399	167
Cash and cash equivalents at end of period	1,971	307
GLDD Corporation [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	-1,007	-11,198
Cash provided by (used in) operating activities	-1,007	-11,198
FINANCING ACTIVITIES:	'	'
Purchase of noncontrolling interest	-205	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	'	-28
Exercise of stock	415	'
Excess income tax benefit from share-based compensation	4	15
Net change in accounts with affiliates, in finance activities	-1,142	538
Borrowings under revolving loans	40,000	79,500
Repayments of revolving loans	-38,000	-58,000
Capital contributions	'	-280
Net cash flows provided by financing activities of continuing operations	1,072	11,198
Cash provided by financing activities	'	11,198
Net decrease in cash and cash equivalents	65	'
Cash and cash equivalents at end of period	65	'
Eliminations [Member]	'	'
INVESTING ACTIVITIES:	'	'
Net change in accounts with affiliates	722	1,722
Net cash flows used in investing activities of continuing operations	722	1,722
Cash used in investing activities	722	1,722
FINANCING ACTIVITIES:	'	'
Net change in accounts with affiliates, in finance activities	-722	-1,722
Net cash flows provided by financing activities of continuing operations	-722	-1,722
Cash provided by financing activities	'	($1,722)