Great Lakes Dredge & Dock (GLDD) 10-Q 6 Nov 14 2014 Q3 Quarterly report Financial data

Document_And_Entity_Informatio

Document And Entity Information	9 Months Ended
	Sep. 30, 2014	Oct. 31, 2014
Document And Entity Information [Abstract]	'	'
Document Type	'10-Q	'
Amendment Flag	'false	'
Document Period End Date	30-Sep-14	'
Document Fiscal Year Focus	'2014	'
Document Fiscal Period Focus	'Q3	'
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	'	60,135,711

Condensed_Consolidated_Balance

Condensed Consolidated Balance Sheets (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
CURRENT ASSETS:	'	'
Cash and cash equivalents	$21,088	$75,338
Accounts receivable-net	98,118	96,515
Contract revenues in excess of billings	85,628	67,432
Inventories	33,194	32,500
Prepaid expenses and other current assets	58,440	44,164
Assets held for sale, current	'	45,104
Total current assets	296,468	361,053
PROPERTY AND EQUIPMENT-Net	382,331	345,620
GOODWILL AND OTHER INTANGIBLE ASSETS-Net	80,885	81,302
INVENTORIES-Noncurrent	37,324	38,496
INVESTMENTS IN JOINT VENTURES	8,445	8,256
Assets held for sale, noncurrent	'	8,856
OTHER	11,745	9,062
TOTAL	817,198	852,645
CURRENT LIABILITIES:	'	'
Accounts payable	139,341	116,121
Accrued expenses	49,755	38,531
Billings in excess of contract revenues	4,978	6,754
Current portion of long term debt	373	'
Liabilities held for sale	'	32,493
Total current liabilities	194,447	193,899
7 3/8% SENIOR NOTES	250,000	250,000
REVOLVING CREDIT FACILITY	35,000	35,000
LONG TERM NOTE PAYABLE	485	'
DEFERRED INCOME TAXES	90,040	108,511
LIABILITIES HELD FOR SALE-Noncurrent	'	1,212
OTHER	11,672	21,922
Total liabilities	581,644	610,544
COMMITMENTS AND CONTINGENCIES (Note 8)	'	'
EQUITY:	'	'
Common stock-$.0001 par value; 90,000 authorized, 60,136 and 59,670 shares issued	6	6
Additional paid-in capital	277,097	275,183
Accumulated deficit	-40,488	-31,770
Accumulated other comprehensive loss	-1,061	-473
Total Great Lakes Dredge & Dock Corporation equity	235,554	242,946
NONCONTROLLING INTERESTS	'	-845
TOTAL EQUITY	235,554	242,101
TOTAL	$817,198	$852,645

Condensed_Consolidated_Balance1

Condensed Consolidated Balance Sheets (Parenthetical) (USD $)	Sep. 30, 2014	Dec. 31, 2013
Common stock, par value	$0.00	$0.00
Common stock, shares authorized	90,000	90,000
Common stock, shares issued	60,136	59,670
Common stock, shares outstanding	60,136	59,670
Senior Notes [Member]	'	'
Interest Rate, Stated Percentage	7.28%	'

Condensed_Consolidated_Stateme

Condensed Consolidated Statements Of Operations (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Consolidated Statements Of Operations [Abstract]	'	'	'	'
CONTRACT REVENUES	$202,198	$187,862	$561,289	$515,140
COSTS OF CONTRACT REVENUES	177,739	160,026	489,720	442,798
Gross profit	24,459	27,836	71,569	72,342
GENERAL AND ADMINISTRATIVE EXPENSES	16,062	17,121	49,850	48,700
Proceeds from loss of use claim	'	'	'	-13,272
(Gain) loss on sale of assets-net	390	-3,214	558	-3,141
Operating income (loss)	8,007	13,929	21,161	40,055
Interest expense-net	-4,702	-5,542	-14,730	-16,671
Equity in earnings (loss) of joint ventures	-5,785	1,427	-9,063	452
Gain on bargain purchase acquisition	'	'	2,197	'
Other income (expense)	384	-178	410	-403
Income (loss) from continuing operations before income taxes	-2,096	9,636	-25	23,433
Income tax (provision) benefit	1,069	-3,060	425	-8,326
Income (loss) from continuing operations	-1,027	6,576	400	15,107
Loss from discontinued operations, net of income taxes	-1,059	-5,310	-9,118	-38,618
Net income (loss)	-2,086	1,266	-8,718	-23,511
Net loss attributable to noncontrolling interest	'	-182	'	-151
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	($2,086)	$1,448	($8,718)	($23,360)
Basic earnings (loss) per share attributable to continuing operations	($0.01)	$0.11	$0.01	$0.25
Basic loss per share attributable to discontinued operations, net of tax	($0.02)	($0.08)	($0.15)	($0.64)
Basic loss per share attributable to discontinued operations, net of tax	($0.03)	$0.03	($0.14)	($0.39)
Basic weighted average shares	60,040	59,526	59,870	59,444
Diluted earnings (loss) per share attributable to continuing operations	($0.01)	$0.11	$0.01	$0.25
Diluted loss per share attributable to discontinued operations, net of tax	($0.02)	($0.09)	($0.15)	($0.64)
Diluted earnings (loss) per share attributable to Great Lakes Dredge & Dock Corporation	($0.03)	$0.02	($0.14)	($0.39)
Diluted weighted average shares	60,040	60,082	60,491	60,000

Condensed_Consolidated_Stateme1

Condensed Consolidated Statements of Comprehensive Income (Loss) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'		'		'		'
Net income (loss)	($2,086)		$1,266		($8,718)		($23,511)
Currency translation adjustment-net of tax (1)	-416	[1]	-51	[1]	-389	[1]	-131	[1]
Net unrealized gain on derivatives-net of tax (2)	-169	[2]	-88	[2]	-199	[2]	-122	[2]
Other comprehensive loss-net of tax	-585		-139		-588		-253
Comprehensive income (loss)	-2,671		1,127		-9,306		-23,764
Comprehensive loss attributable to noncontrolling interests	'		182		'		151
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	($2,671)		$1,309		($9,306)		($23,613)
[1]	Net of income tax (expense) benefit of $276 and $(34) for the three months ended September 30, 2014 and 2013, respectively, and $259 and $(85) for nine months ended September 30, 2014 and 2013, respectively.
[2]	Net of income tax expense of $111 and $58 for the three months ended September 30, 2014 and 2013, respectively, and $132 and $81 for the nine months ended September 30, 2014 and 2013, respectively.

Condensed_Consolidated_Stateme2

Condensed Consolidated Statements of Comprehensive Income (Loss) (Parenthetical) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Consolidated Statements of Comprehensive Income (Loss) [Abstract]	'	'	'	'
Currency translation adjustment, tax	$276	($34)	$259	($85)
Net unrealized (gain) loss on derivatives-net of tax	$111	$58	$132	$81

Condensed_Consolidated_Stateme3

Condensed Consolidated Statements Of Equity (USD $)	Common Stock [Member]	Additional Paid-In Capital [Member]	Accumulated Deficit [Member]	Accumulated Other Comprehensive Loss [Member]	Noncontrolling Interests [Member]	Total
In Thousands
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	'	2,452	'	'	'	2,452
Share-based compensation, Shares	75	'	'	'	'	'
Vesting of restricted stock units, including impact of shares withheld for taxes, value	'	-305	'	'	'	-305
Vesting of restricted stock units, including impact of shares withheld for taxes, shares	69	'	'	'	'	'
Exercise of options and purchases from employee stock plans, Value	'	581	'	'	'	581
Exercise of options and purchases from employee stock plans, Shares	122	'	'	'	'	'
Excess income tax benefit from share based compensation	'	133	'	'	'	133
Distributions paid to noncontrolling interests	'	'	'	'	-3	-3
Net loss	'	'	-23,360	'	-151	-23,511
Other comprehensive loss-net of tax	'	'	'	-253	'	-253
BALANCE - value at Sep. 30, 2013	6	274,279	-20,769	-633	-364	252,519
BALANCE - shares at Sep. 30, 2013	59,625	'	'	'	'	'
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	'	1,816	'	'	'	1,816
Share-based compensation, Shares	94	'	'	'	'	'
Vesting of restricted stock units, including impact of shares withheld for taxes, value	'	-501	'	'	'	-501
Vesting of restricted stock units, including impact of shares withheld for taxes, shares	107	'	'	'	'	'
Exercise of options and purchases from employee stock plans, Value	'	1,542	'	'	'	1,542
Exercise of options and purchases from employee stock plans, Shares	265	'	'	'	'	'
Excess income tax benefit from share based compensation	'	45	'	'	'	45
Distributions paid to noncontrolling interests	'	-988	'	'	845	-143
Net loss	'	'	-8,718	'	'	-8,718
Other comprehensive loss-net of tax	'	'	'	-588	'	-588
BALANCE - value at Sep. 30, 2014	$6	$277,097	($40,488)	($1,061)	'	$235,554
BALANCE - shares at Sep. 30, 2014	60,136	'	'	'	'	'

Condensed_Condensed_Consolidat

Condensed Condensed Consolidated Statements Of Cash Flows (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES:	'	'
Net loss	($8,718)	($23,511)
Loss from discontinued operations, net of income taxes	-9,118	-38,618
Income (loss) from continuing operations	400	15,107
Adjustments to reconcile net loss to net cash flows used in operating activities:	'	'
Depreciation and amortization	32,744	33,777
Equity in (earnings) loss of joint ventures	9,063	-452
Deferred income taxes	-11,034	-936
(Gain) loss on sale of assets	558	-3,141
Gain on bargain purchase acquisition	2,197	'
Amortization of deferred financing fees	1,036	865
Unrealized net loss from mark-to-market valuations of derivatives	1,051	'
Unrealized foreign currency (gain) loss	-561	99
Share-based compensation expense	1,816	2,452
Excess income tax benefit from share based compensation	-45	-133
Changes in assets and liabilities:	'	'
Accounts receivable	-3,791	3,591
Contract revenues in excess of billings	-18,292	-22,201
Inventories	504	-3,955
Prepaid expenses and other current assets in operation	2,743	10,793
Accounts payable and accrued expenses	10,927	5,278
Billings in excess of contract revenues	-1,776	-6,630
Other noncurrent assets and liabilities	-2,369	-1,703
Net cash flows provided by operating activities of continuing operations	15,291	11,225
Net cash flows used in operating activities of discontinued operations	-5,024	-8,491
Cash provided by operating activities	10,267	2,734
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-66,433	-37,968
Proceeds from dispositions of property and equipment	1,614	4,194
Proceeds from (payments on) vendor performance obligations	-3,100	13,600
Payments for acquisitions of businesses	-2,048	'
Net cash flows used in investing activities of continuing operations	-69,967	-20,174
Net cash flows provided by investing activities of discontinued operations	5,275	-149
Cash used in investing activities	-64,692	-20,323
FINANCING ACTIVITIES:	'	'
Deferred financing fees	-845	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	-501	-305
Repayments of equipment debt	-121	-6
Purchase of noncontrolling interest	-205	'
Exercise of options and purchases from employee stock plans	1,542	581
Excess income tax benefit from share-based compensation	45	133
Borrowings under revolving loans	105,000	194,500
Repayments of revolving loans	-105,000	-149,500
Net cash flows provided by (used in) financing activities of continuing operations	-85	34,856
Net cash flows provided by (used in) financing activities of discontinued operations	'	-39
Cash provided by (used in) financing activities	-85	34,817
Effect of foreign currency exchange rates on cash and cash equivalents	260	-346
Net increase (decrease) in cash and cash equivalents	-54,250	16,882
Cash and cash equivalents at beginning of period	75,338	24,440
Cash and cash equivalents at end of period	21,088	41,322
Supplemental Cash Flow Information	'	'
Cash paid for interest	18,936	19,525
Cash paid (refunded) for income taxes	-9,364	431
Non-cash Investing and Financing Activities	'	'
Property and equipment purchased but not yet paid	18,401	12,432
Property and equipment purchased on capital leases and equipment notes	1,616	'
Purchase of noncontrolling interest	$988	'

Basis_of_presentation

Basis of presentation	9 Months Ended
	Sep. 30, 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 September 30, 2014, and its results of operations for the three and nine months ended September 30, 2014 and 2013 and cash flows for the nine months ended September 30, 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 Company performed its most recent annual test of impairment as of July 1, 2014 for the goodwill in both the dredging and environmental & remediation segments with no indication of goodwill impairment as of the test date. The Company will perform its next scheduled annual test of goodwill in the third quarter of 2015.
	The condensed consolidated results of operations and comprehensive income for the interim periods presented herein are not necessarily indicative of the results to be expected for the full year.
	Recent Accounting Pronouncements
	In May 2014, the Financial Accounting Standards Board issued Accounting Standard Update No. 2014-09 (“ASU 2014-09”),  Revenue from Contracts with Customers (Topic 606), which supersedes the existing revenue recognition requirements. ASU 2014-09 is based on the principle that revenue is recognized to depict the transfer of goods or services to customers in an amount that reflects the consideration to which the entity expects to be entitled in exchange for those goods or services. ASU 2014-09 is effective for fiscal years beginning after December 15, 2016, including interim periods within that reporting period, which will be our first quarter of fiscal 2017.  Early adoption is not permitted. We are currently evaluating the impact of ASU 2014-09 on our consolidated financial statements.

Earnings_per_share

Earnings per share	9 Months Ended
	Sep. 30, 2014
Earnings per share [Abstract]	'
Earnings Per Share	'
	2.   Earnings per share
	Basic earnings per share is computed by dividing net income attributable to common stockholders by the weighted-average number of common shares outstanding during the reporting period. Diluted earnings per share is computed similar to basic earnings per share except that it reflects the potential dilution that could occur if dilutive securities or other obligations to issue common stock were exercised or converted into common stock. For the three months ended September 30, 2014, the dilutive effect of 521 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 these periods. Additionally, for the three and nine months ended September 30, 2014,  664 thousand and 500 thousand shares, respectively, of stock options or restricted stock units 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				Nine Months Ended
	(shares in thousands)	September 30,				September 30,
		2014		2013		2014		2013
	Income (loss) from continuing operations	$	-1,027	$	6,576	$	400	$	15,107
	Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation		-1,059		-5,128		-9,118		-38,467
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		-2,086		1,448		-8,718		-23,360
	Weighted-average common shares outstanding — basic		60,040		59,526		59,870		59,444
	Effect of stock options and restricted stock units		-		556		621		556
	Weighted-average common shares outstanding — diluted		60,040		60,082		60,491		60,000
	Earnings (loss) per share from continuing operations — basic	$	-0.01	$	0.11	$	0.01	$	0.25
	Earnings (loss) per share from continuing operations — diluted	$	-0.01	$	0.11	$	0.01	$	0.25

Accounts_Receivable_And_Contra

Accounts Receivable And Contracts In Progress	9 Months Ended
	Sep. 30, 2014
Accounts Receivable And Contracts In Progress [Abstract]	'
Accounts Receivables And Contracts In Progress	'
	3.   Accounts receivable and contracts in progress
	Accounts receivable at September 30, 2014 and December 31, 2013 are as follows:
		September 30,		December 31,
		2014		2013
	Completed contracts	$	12,718	$	17,361
	Contracts in progress		71,402		62,177
	Retainage		16,450		18,506
			100,570		98,044
	Allowance for doubtful accounts		-1,529		-1,529
	Total accounts receivable—net	$	99,041	$	96,515
	Current portion of accounts receivable—net	$	98,118	$	96,515
	Long-term accounts receivable and retainage		923		-
	Total accounts receivable—net	$	99,041	$	96,515
	The components of contracts in progress at September 30, 2014 and December 31, 2013 are as follows:
		September 30,		December 31,
		2014		2013
	Costs and earnings in excess of billings:
	Costs and earnings for contracts in progress	$	737,986	$	435,470
	Amounts billed		-660,952		-370,730
	Costs and earnings in excess of billings for contracts in progress		77,034		64,740
	Costs and earnings in excess of billings for completed contracts		8,594		2,692
	Total contract revenues in excess of billings	$	85,628	$	67,432
	Billings in excess of costs and earnings:
	Amounts billed	$	-175,854	$	-156,794
	Costs and earnings for contracts in progress		170,876		150,040
	Total billings in excess of contract revenues	$	-4,978	$	-6,754

Accrued_Expenses

Accrued Expenses	9 Months Ended
	Sep. 30, 2014
Accrued Expenses [Abstract]	'
Accrued Expenses	'
	4.   Accrued expenses
	Accrued expenses at September 30, 2014 and December 31, 2013 are as follows:
		September 30,		December 31,
		2014		2013
	Insurance	$	13,219	$	8,649
	Payroll and employee benefits		8,406		13,664
	Income and other taxes		4,803		3,709
	Interest		3,309		8,066
	Percentage of completion adjustment		451		2,135
	Other		19,567		2,308
	Total accrued expenses	$	49,755	$	38,531

Longterm_Debt

Long-term Debt	9 Months Ended
	Sep. 30, 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, as subsequently amended, provides for a senior revolving credit facility in an aggregate principal amount of up to $210,000, multicurrency borrowings up to a $50,000 sublimit and swingline loans up to a $10,000 sublimit. The Credit Agreement also includes an incremental loans feature that will allow the Company to increase the senior revolving credit facility by an aggregate principal amount of up to $15,000. This 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.
	On September 15, 2014, the Company entered into the fifth amendment (the “Fifth Amendment”) to the Credit Agreement which exercised a portion of the incremental loans feature of the Credit Agreement that allowed the Company to increase the aggregate revolving commitment. A new lender provided an incremental commitment of $35,000 increasing the aggregate revolving commitment to $210,000. Additionally, the Fifth Amendment allowed full use of the aggregate revolving commitment for the issuance of letters of credit and decreasing the required ratio of aggregate orderly liquidation value of pledged collateral from 1.5 times to 1.27 times the aggregate revolving commitment. The Fifth Amendment further amended the Credit Agreement to secured and collateralized by perfected liens on certain of the Company’s vessels and its domestic accounts receivable, subject to permitted liens and prior interests of other parties.
	In connection with the Company’s entry into the Fifth Amendment, Zurich American Insurance Company, the Company’s surety provider, secured permitted second mortgages on the same vessels securing the obligations under the Credit Agreement.
	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.
	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 September 30, 2014, the Company had $35,000 of borrowings on the revolver and $117,761 of letters of credit outstanding, resulting in $57,239 of availability under the Credit Agreement. At September 30, 2014, the Company was in compliance with its various financial covenants under its Credit Agreement.
	On September 15, 2014, the Company terminated its $24,000 international letter of credit facility with Wells Fargo Bank, National Association, as successor by merger to Wells Fargo HSBC Trade Bank, as amended. On the date of termination, there were no letters of credit or other indebtedness outstanding under this facility, and the loan documents providing for the facility, and the liens and security interests securing it, were terminated and released.
	At September 30, 2014, the Company also had $250,000 of 7.375% senior notes outstanding, which mature in February 2019.
	Subsequent to September 30, 2014, the Company entered into transactions affecting its long-term debt. See Note 12.

Fair_Value_Measurements

Fair Value Measurements	9 Months Ended
	Sep. 30, 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 times, the Company holds 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 September 30, 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	$	1,051		$	-		$	1,051		$	-
						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 September 30, 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 September 30, 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 August 2015. As of September 30, 2014, there were 4.1 million gallons remaining on these contracts which represent approximately 80% of the Company’s forecasted fuel purchases through August 2015. Under these swap agreements, the Company will pay fixed prices ranging from $2.86 to $3.01 per gallon.
	At September 30, 2014, the fair value liability of the fuel hedge contracts was estimated to be $1,051 and is recorded in accrued expenses. The gain reclassified to earnings from changes in fair value of derivatives, net of cash settlements and taxes, for the nine months ended September 30, 2014 was $332. 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 September 30, 2014 and December 31, 2013 is as follows:
				Fair Value at
				September 30,			December 31,
		Balance Sheet Location		2014			2013
	Asset derivatives:
	Derivatives designated as hedging instruments
	Fuel hedge contracts	Prepaid expenses and other current assets		$	-		$	332
	Liability derivatives:
	Derivatives not designated as hedging instruments
	Fuel hedge contracts	Accrued expenses		$	1,051		$	-
	Accumulated other comprehensive loss
	Changes in the components of the accumulated balances of other comprehensive income (loss) are as follows:
				Three Months Ended						Nine Months Ended
				September 30,						September 30,
				2014			2013			2014			2013
	Cumulative translation adjustments—net of tax			$	-416		$	-51		$	-389		$	-131
	Derivatives:
	Reclassification of derivative (gains) losses to earnings—net of tax				-306			-53			-332			237
	Change in fair value of derivatives—net of tax				136			-35			132			-359
	Net unrealized gain on derivatives—net of tax				-169			-88			-199			-122
	Total other comprehensive loss			$	-585		$	-139		$	-588		$	-253
	Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings are as follows:
				Three Months Ended						Nine Months Ended
				September 30,						September 30,
		Statement of Operations Location		2014			2013			2014			2013
	Derivatives:
	Fuel hedge contracts	Costs of contract revenues		$	-241		$	-88		$	-286		$	395
		Income tax (provision) benefit			65			-35			46			158
				$	-306		$	-53		$	-332		$	237
	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 the 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 September 30, 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 $256,875 at September 30, 2014, which is a Level 1 fair value measurement as the senior notes value was obtained using quoted prices in active markets.

ShareBased_Compensation

Share-Based Compensation	9 Months Ended
	Sep. 30, 2014
Share-based compensation[Abstract]	'
Share-based Compensation	'
	7.   Share-based compensation
	The Company’s 2007 Long-Term Incentive Plan permits the granting of stock options, stock appreciation rights, restricted stock and restricted stock units to its employees and directors for up to 5.8 million shares of common stock.
	In May 2014, the Company granted 337 thousand options to purchase shares of common stock and 182 thousand restricted stock units to certain employees pursuant to the plan. In addition, all non-employee directors on the Company’s board of directors are paid a portion of their board-related compensation in stock grants. Compensation cost charged to expense related to share-based compensation arrangements was $828 and $1,816,  respectively, for the three and nine months ended September 30, 2014 and $1,000 and $2,452 for the three and nine months ended September 30, 2013, respectively.

Commitments_And_Contingencies

Commitments And Contingencies	9 Months Ended
	Sep. 30, 2014
Commitments And Contingencies [Abstract]	'
Commitments And Contingencies	'
	8.   Commitments and contingencies
	Commercial commitments
	Performance and bid bonds are customarily required for dredging and marine construction projects, as well as some environmental & 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 September 30, 2014, the Company had outstanding performance bonds totaling approximately $822,283, of which $49,613 relates to projects accounted for in discontinued operations. The revenue value remaining in backlog related to the projects of continuing operations totaled approximately $603,748.
	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. After briefing and oral argument by the parties, the Court entered an order on October 21, 2014 denying that motion to dismiss. 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 was otherwise stayed pending 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 was also stayed pending a ruling on the motion to dismiss the securities class action. The parties have agreed to continue to stay these matters until early December 2014.
	As discussed in Note 10, 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.

Investments

Investments	9 Months Ended
	Sep. 30, 2014
Investments [Abstract]	'
Investments	'
	9.   Investments
	The Company owns 50% of TerraSea Environmental Solutions (“TerraSea”) as a joint venture. TerraSea is engaged in the environmental services business through its ability to remediate contaminated soil and dredged sediment treatment. The Company has begun the discussion with its joint venture partner in TerraSea regarding the winddown of operations and liquidation of the investments.
	The Company accounts for this investment under the equity method. The following is summarized financial information for this entity:
		Nine Months Ended
		September 30,
		2014		2013
	Revenue	$	5,853	$	4,424
	Gross profit		-15,241		-714
	Loss from continuing operations		-16,110		-1,608
	Net Loss		-16,110		-1,608

Business_Dispositions

Business Dispositions	9 Months Ended
	Sep. 30, 2014
Business Dispositions [Abstract]	'
Business Combinations And Reorganizations	'
	10.   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 former subsidiaries that comprised the historical demolition business.  Under the terms of the agreement, the Company received cash of $5,309 and retained the right to receive additional proceeds based upon future collections of outstanding accounts receivable and work in process existing at the date of close, including recovery of outstanding claims for additional compensation from customers, and net of future payments of accounts payable existing at the date of close, including any future payments of obligations associated with outstanding claims.  In the fourth quarter of 2013, the Company recorded a preliminary loss on disposal of assets held for sale in discontinued operations, which is subject to change based upon subsequent adjustments to the purchase price related to additional proceeds.
	The results of the businesses have been reported in discontinued operations as follows:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Revenue	$	-	$	10,964	$	14,439	$	25,396
	Loss before income taxes from discontinued operations	$	-1,053	$	-7,687	$	-18,393	$	-48,608
	Income tax (provision) benefit		-6		2,377		9,275		9,990
	Loss from discontinued operations, net of income taxes	$	-1,059	$	-5,310	$	-9,118	$	-38,618

Segment_Information

Segment Information	9 Months Ended
	Sep. 30, 2014
Segment Information [Abstract]	'
Segment Information	'
	11.   Segment information
	The Company and its subsidiaries currently operate in two reportable segments: dredging and environmental & remediation. The Company’s financial reporting systems present various data for management to run the business, including profit and loss statements prepared according to the segments presented. Management uses operating income to evaluate performance between the two segments. Segment information for the periods presented is provided as follows:
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Dredging
	Contract revenues	$	167,079	$	155,469	$	486,153	$	465,915
	Operating income		5,733		13,129		24,157		46,698
	Environmental & remediation
	Contract revenues	$	37,182	$	36,114	$	79,224	$	53,215
	Operating income (loss)		2,274		800		-2,996		-6,643
	Intersegment revenues	$	-2,063	$	-3,721		-4,088		-3,990
	Total
	Contract revenues	$	202,198	$	187,862	$	561,289	$	515,140
	Operating income		8,007		13,929		21,161		40,055
	Foreign dredging revenue of $40,040 and $85,691 for the three and nine months ended September 30, 2014, respectively, was primarily attributable to work on the Wheatstone LNG project in Western Australia as well as work done in Brazil and the Middle East. Foreign dredging revenue for the three and nine months ended September 30, 2013 was $32,651 and $104,384, respectively.
	During the nine months ended September 30, 2014, the Company earned significant revenue from a large, single customer foreign contract. As a result of the successful resolution of contingencies with the customer, a revision to the estimated gross profit percentage was recorded in the period. The cumulative net impact of this change increased gross profit by $12,423 for the three months ended September 30, 2014. Due to uncertainties inherent in estimations, the Company could record further revisions to our gross profit percentage on this contract as it is completed.
	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	9 Months Ended
	Sep. 30, 2014
Subsidiary Guarantors [Abstract]	'
Subsidiary Guarantors	'
	13.   Subsidiary guarantors
	The Company’s long-term debt at September 30, 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 September 30, 2014 and December 31, 2013;
		(ii)	statements of operations and comprehensive loss for the three and nine months ended September 30, 2014 and 2013; and
		(iii)	statements of cash flows for the nine months ended September 30, 2014 and 2013.
	Certain amounts included in the following condensed consolidating statements of cash flows for the nine months ended September 30, 2013 have been revised to conform with current year presentation reflecting intercompany borrowings and payments as either investing or financing activities.
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF SEPTEMBER 30, 2014
	(In thousands)
	ASSETS	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	CURRENT ASSETS:
	Cash and cash equivalents	$	18,212		$	2,873		$	3		$	-		$	21,088
	Accounts receivable — net		98,118			-			-			-			98,118
	Receivables from affiliates		164,731			3,561			33,406			-201,698			-
	Contract revenues in excess of billings		82,717			2,911			-			-			85,628
	Inventories		33,194			-			-			-			33,194
	Prepaid expenses and other current assets		60,207			875			-2,642			-			58,440
	Total current assets		457,179			10,220			30,767			-201,698			296,468
	PROPERTY AND EQUIPMENT—Net		382,325			6			-			-			382,331
	GOODWILL AND OTHER INTANGIBLE ASSETS—Net		80,885			-			-			-			80,885
	INVENTORIES — Noncurrent		37,324			-			-			-			37,324
	INVESTMENTS IN JOINT VENTURES		8,445			-			-			-			8,445
	INVESTMENTS IN SUBSIDIARIES		3,722			-			594,364			-598,086			-
	OTHER		7,409			3			4,333			-			11,745
	TOTAL	$	977,289		$	10,229		$	629,464		$	-799,784		$	817,198
	LIABILITIES AND EQUITY
	CURRENT LIABILITIES:
	Accounts payable	$	138,137		$	903		$	301		$	-		$	139,341
	Payables to affiliates		175,587			12,327			13,784			-201,698			-
	Accrued expenses		45,663			221			3,871			-			49,755
	Billings in excess of contract revenues		4,978			-			-			-			4,978
	Current portion of long term debt		373			-			-			-			373
	Total current liabilities		364,738			13,451			17,956			-201,698			194,447
	7 3/8% SENIOR NOTES		-			-			250,000			-			250,000
	REVOLVING CREDIT FACILITY		-			-			35,000			-			35,000
	LONG TERM NOTE PAYABLE		485			-			-			-			485
	DEFERRED INCOME TAXES		-363			-			90,403			-			90,040
	OTHER		11,121			-			551			-			11,672
	Total liabilities		375,981			13,451			393,910			-201,698			581,644
	Total Great Lakes Dredge & Dock Corporation Equity		601,308			-3,222			235,554			-598,086			235,554
	NONCONTROLLING INTERESTS		-			-			-			-			-
	TOTAL EQUITY		601,308			-3,222			235,554			-598,086			235,554
	TOTAL	$	977,289		$	10,229		$	629,464		$	-799,784		$	817,198
	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 SEPTEMBER 30, 2014
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	198,934		$	3,264		$	-		$	-		$	202,198
Costs of contract revenues		-170,911			-6,828			-			-			-177,739
Gross profit		28,023			-3,564			-			-			24,459
OPERATING EXPENSES:
General and administrative expenses		15,988			1			73			-			16,062
Loss on sale of assets—net		390			-			-			-			390
Operating income (loss)		11,645			-3,565			-73			-			8,007
Interest expense—net		-60			-			-4,642			-			-4,702
Equity in earnings of subsidiaries		54			-			3,316			-3,370			-
Equity in loss of joint ventures		-5,785			-			-			-			-5,785
Other income		384			-			-			-			384
Income (loss) from continuing operations before income taxes		6,238			-3,565			-1,399			-3,370			-2,096
Income tax benefit		697			-			372			-			1,069
Income (loss) from continuing operations		6,935			-3,565			-1,027			-3,370			-1,027
Loss from discontinued operations, net of income taxes		-1,059			-			-1,059			1,059			-1,059
Net income (loss)		5,876			-3,565			-2,086			-2,311			-2,086
Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	5,876		$	-3,565		$	-2,086		$	-2,311		$	-2,086
Comprehensive income (loss) attributable to	$	5,707		$	-3,981		$	-2,671		$	-1,726		$	-2,671
Great Lakes Dredge & Dock Corporation
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	179,514		$	8,348		$	-		$	-		$	187,862
Costs of contract revenues		-149,966			-10,060			-			-			-160,026
Gross profit		29,548			-1,712			-			-			27,836
OPERATING EXPENSES:
General and administrative expenses		17,121			-			-			-			17,121
Proceeds from loss of use claim		-			-			-			-			-
Gain on sale of assets—net		-3,214			-			-			-			-3,214
Operating income (loss)		15,641			-1,712			-			-			13,929
Interest expense—net		-65			-71			-5,406			-			-5,542
Equity in earnings of subsidiaries		304			-			12,711			-13,015			-
Equity in earnings of joint ventures		1,427			-			-			-			1,427
Other income (expense)		-187			9			-			-			-178
Income (loss) from continuing operations before income taxes		17,120			-1,774			7,305			-13,015			9,636
Income tax provision		-2,331			-			-729			-			-3,060
Income (loss) from continuing operations		14,789			-1,774			6,576			-13,015			6,576
Loss from discontinued operations, net of income taxes		-5,310			-198			-5,310			5,508			-5,310
Net income (loss)		9,479			-1,972			1,266			-7,507			1,266
Net loss attributable to noncontrolling interest		-			-			182			-			182
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		9,479			-1,972			1,448			-7,507			1,448
Comprehensive income (loss) attributable to	$	9,391		$	-2,023		$	1,309		$	-7,368		$	1,309
Great Lakes Dredge & Dock Corporation
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2014
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	540,199		$	21,090		$	-		$	-		$	561,289
Costs of contract revenues		-463,718			-26,002			-			-			-489,720
Gross profit		76,481			-4,912			-			-			71,569
OPERATING EXPENSES:
General and administrative expenses		49,776			1			73			-			49,850
Proceeds from loss of use claim		-			-			-			-			-
Loss on sale of assets—net		558			-			-			-			558
Operating income (loss)		26,147			-4,913			-73			-			21,161
Interest expense—net		91			-261			-14,560			-			-14,730
Equity in earnings (loss) of subsidiaries		-52			-			15,915			-15,863			-
Equity in loss of joint ventures		-9,063			-			-			-			-9,063
Gain on bargain purchase acquisition		2,197			-			-			-			2,197
Other income		403			7			-			-			410
Income (loss) from continuing operations before income taxes		19,723			-5,167			1,282			-15,863			-25
Income tax (provision) benefit		1,307			-			-882			-			425
Income (loss) from continuing operations		21,030			-5,167			400			-15,863			400
Loss from discontinued operations, net of income taxes		-9,118			-1,343			-9,118			10,461			-9,118
Net income (loss)		11,912			-6,510			-8,718			-5,402			-8,718
Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	11,912		$	-6,510		$	-8,718		$	-5,402		$	-8,718
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	$	11,713		$	-6,899		$	-9,306		$	-4,814		$	-9,306
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	497,486		$	17,654		$	-		$	-		$	515,140
Costs of contract revenues		-422,764			-20,034			-			-			-442,798
Gross profit		74,722			-2,380			-			-			72,342
OPERATING EXPENSES:
General and administrative expenses		48,695			5			-			-			48,700
Proceeds from loss of use claim		-13,272			-			-			-			-13,272
Gain on sale of assets—net		-3,141			-			-			-			-3,141
Operating income (loss)		42,440			-2,385			-			-			40,055
Interest expense—net		-214			-160			-16,297			-			-16,671
Equity in earnings of subsidiaries		306			-			39,777			-40,083			-
Equity in earnings of joint ventures		452			-			-			-			452
Other expense		-55			-348			-			-			-403
Income (loss) from continuing operations before income taxes		42,929			-2,893			23,480			-40,083			23,433
Income tax (provision) benefit		45			2			-8,373			-			-8,326
Income (loss) from continuing operations		42,974			-2,891			15,107			-40,083			15,107
Loss from discontinued operations, net of income taxes		-38,618			-265			-38,618			38,883			-38,618
Net income (loss)		4,356			-3,156			-23,511			-1,200			-23,511
Net loss attributable to noncontrolling interest		-			-			151			-			151
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	4,356		$	-3,156		$	-23,360		$	-1,200		$	-23,360
Comprehensive income (loss) attributable to	$	4,234		$	-3,287		$	-23,613		$	-947		$	-23,613
Great Lakes Dredge & Dock Corporation
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 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		$	24,488		$	-3,357		$	-5,840		$	-		$	15,291
Net cash flows used in operating activities of discontinued operations			-4,000			-1,024			-			-			-5,024
Cash provided by (used in) operating activities			20,488			-4,381			-5,840			-			10,267
INVESTING ACTIVITIES:
Purchases of property and equipment			-66,433			-			-			-			-66,433
Proceeds from dispositions of property and equipment			1,614			-			-			-			1,614
Payments on vendor performance obligations			-3,100			-			-			-			-3,100
Payments for acquisitions of businesses			-2,048			-			-			-			-2,048
Net change in accounts with affiliates			-9,402			-			-			9,402			-
Net cash flows used in investing activities of continuing operations			-79,369			-			-			9,402			-69,967
Net cash flows provided by investing activities of discontinued operations			5,275			-			-			-			5,275
Cash used in investing activities			-74,094			-			-			9,402			-64,692
FINANCING ACTIVITIES:
Deferred financing fees			-			-			-845			-			-845
Taxes paid on settlement of vested share awards			-			-			-501			-			-501
Repayments of equipment debt			-121			-			-			-			-121
Purchase of noncontrolling interest			-			-			-205			-			-205
Net change in accounts with affiliates			-			3,595			5,807			-9,402			-
Exercise of options and purchases from employee stock plans			-			-			1,542			-			1,542
Excess income tax benefit from share-based compensation			-			-			45			-			45
Borrowings under revolving loans			-			-			105,000			-			105,000
Repayments of revolving loans			-			-			-105,000			-			-105,000
Net cash flows provided by (used in) financing activities of continuing operations			-121			3,595			5,843			-9,402			-85
Net cash flows provided by (used in) financing activities of discontinued operations			-			-			-			-			-
Cash provided by (used in) financing activities			-121			3,595			5,843			-9,402			-85
Effect of foreign currency exchange rates on cash and cash equivalents			-			260			-			-			260
Net increase (decrease) in cash and cash equivalents			-53,727			-526			3			-			-54,250
Cash and cash equivalents at beginning of period			71,939			3,399			-			-			75,338
Cash and cash equivalents at end of period		$	18,212		$	2,873		$	3		$	-		$	21,088
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 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		$	47,543		$	-6,776		$	-29,542		$	-		$	11,225
Net cash flows used in operating activities of discontinued operations			-8,054			-437			-			-			-8,491
Cash provided by (used in) operating activities			39,489			-7,213			-29,542			-			2,734
INVESTING ACTIVITIES:
Purchases of property and equipment			-37,968			-			-			-			-37,968
Proceeds from dispositions of property and equipment			4,194			-			-			-			4,194
Proceeds from vendor performance obligations			13,600			-			-			-			13,600
Net change in accounts with affiliates			-5,309			-			-			5,309			-
Net cash flows used in investing activities of continuing operations			-25,483			-			-			5,309			-20,174
Net cash flows used in investing activities of discontinued operations			-149			-			-			-			-149
Cash used in investing activities			-25,632			-			-			5,309			-20,323
FINANCING ACTIVITIES:
Repayments of long term note payable			-			-			-10,547			-			-10,547
Taxes paid on settlement of vested share awards			-			-			-305			-			-305
Repayment of equipment debt			-6			-			-			-			-6
Net change in accounts with affiliates			-			9,700			-4,391			-5,309			-
Exercise of options and purchases from employee stock plans			-			-			581			-			581
Excess income tax benefit from share-based compensation			-			-			133			-			133
Borrowings under revolving loans			-			-			194,500			-			194,500
Repayments of revolving loans			-			-			-149,500			-			-149,500
Capital contributions			-			926			-926			-			-
Net cash flows provided by (used in) financing activities of continuing operations			-6			10,626			29,545			-5,309			34,856
Net cash flows used in financing activities of discontinued operations			-36			-			-3			-			-39
Cash provided by (used in) financing activities			-42			10,626			29,542			-5,309			34,817
Effect of foreign currency exchange rates on cash and cash equivalents			-			-346			-			-			-346
Net increase in cash and cash equivalents			13,815			3,067			-			-			16,882
Cash and cash equivalents at beginning of period			24,272			168			-			-			24,440
Cash and cash equivalents at end of period		$	38,087		$	3,235		$	-		$	-		$	41,322

Earnings_per_share_Tables

Earnings per share (Tables)	9 Months Ended
	Sep. 30, 2014
Earnings per share [Abstract]	'
Computations For Basic And Diluted Earnings Per Share	'
		Three Months Ended				Nine Months Ended
	(shares in thousands)	September 30,				September 30,
		2014		2013		2014		2013
	Income (loss) from continuing operations	$	-1,027	$	6,576	$	400	$	15,107
	Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation		-1,059		-5,128		-9,118		-38,467
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		-2,086		1,448		-8,718		-23,360
	Weighted-average common shares outstanding — basic		60,040		59,526		59,870		59,444
	Effect of stock options and restricted stock units		-		556		621		556
	Weighted-average common shares outstanding — diluted		60,040		60,082		60,491		60,000
	Earnings (loss) per share from continuing operations — basic	$	-0.01	$	0.11	$	0.01	$	0.25
	Earnings (loss) per share from continuing operations — diluted	$	-0.01	$	0.11	$	0.01	$	0.25

Accounts_Receivable_And_Contra1

Accounts Receivable And Contracts In Progress (Tables)	9 Months Ended
	Sep. 30, 2014
Accounts Receivable And Contracts In Progress [Abstract]	'
Schedule Of Accounts Receivable	'
		September 30,		December 31,
		2014		2013
	Completed contracts	$	12,718	$	17,361
	Contracts in progress		71,402		62,177
	Retainage		16,450		18,506
			100,570		98,044
	Allowance for doubtful accounts		-1,529		-1,529
	Total accounts receivable—net	$	99,041	$	96,515
	Current portion of accounts receivable—net	$	98,118	$	96,515
	Long-term accounts receivable and retainage		923		-
	Total accounts receivable—net	$	99,041	$	96,515
Components Of Contracts In Progress	'
		September 30,		December 31,
		2014		2013
	Costs and earnings in excess of billings:
	Costs and earnings for contracts in progress	$	737,986	$	435,470
	Amounts billed		-660,952		-370,730
	Costs and earnings in excess of billings for contracts in progress		77,034		64,740
	Costs and earnings in excess of billings for completed contracts		8,594		2,692
	Total contract revenues in excess of billings	$	85,628	$	67,432
	Billings in excess of costs and earnings:
	Amounts billed	$	-175,854	$	-156,794
	Costs and earnings for contracts in progress		170,876		150,040
	Total billings in excess of contract revenues	$	-4,978	$	-6,754

Accrued_Expenses_Tables

Accrued Expenses (Tables)	9 Months Ended
	Sep. 30, 2014
Accrued Expenses [Abstract]	'
Accrued Expenses	'
		September 30,		December 31,
		2014		2013
	Insurance	$	13,219	$	8,649
	Payroll and employee benefits		8,406		13,664
	Income and other taxes		4,803		3,709
	Interest		3,309		8,066
	Percentage of completion adjustment		451		2,135
	Other		19,567		2,308
	Total accrued expenses	$	49,755	$	38,531

Fair_Value_Measurements_Tables

Fair Value Measurements (Tables)	9 Months Ended
	Sep. 30, 2014
Fair Value Measurements [Abstract]	'
Schedule Of Fair Values Of Financial Instruments And Nonfinancial Assets And Liabilities Measured At The Reporting Date	'
						Fair Value Measurements at Reporting Date Using
	Description	At September 30, 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	$	1,051		$	-		$	1,051		$	-
						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
				September 30,			December 31,
		Balance Sheet Location		2014			2013
	Asset derivatives:
	Derivatives designated as hedging instruments
	Fuel hedge contracts	Prepaid expenses and other current assets		$	-		$	332
	Liability derivatives:
	Derivatives not designated as hedging instruments
	Fuel hedge contracts	Accrued expenses		$	1,051		$	-
Changes In Components Of Accumulated other comprehensive loss (Table)	'
				Three Months Ended						Nine Months Ended
				September 30,						September 30,
				2014			2013			2014			2013
	Cumulative translation adjustments—net of tax			$	-416		$	-51		$	-389		$	-131
	Derivatives:
	Reclassification of derivative (gains) losses to earnings—net of tax				-306			-53			-332			237
	Change in fair value of derivatives—net of tax				136			-35			132			-359
	Net unrealized gain on derivatives—net of tax				-169			-88			-199			-122
	Total other comprehensive loss			$	-585		$	-139		$	-588		$	-253
Adjustments reclassified from accumulated balances of other comprehensive income (loss) to earnings	'
				Three Months Ended						Nine Months Ended
				September 30,						September 30,
		Statement of Operations Location		2014			2013			2014			2013
	Derivatives:
	Fuel hedge contracts	Costs of contract revenues		$	-241		$	-88		$	-286		$	395
		Income tax (provision) benefit			65			-35			46			158
				$	-306		$	-53		$	-332		$	237

Investments_Tables

Investments (Tables)	9 Months Ended
	Sep. 30, 2014
Investments [Abstract]	'
Schedule Of Investments	'
		Nine Months Ended
		September 30,
		2014		2013
	Revenue	$	5,853	$	4,424
	Gross profit		-15,241		-714
	Loss from continuing operations		-16,110		-1,608
	Net Loss		-16,110		-1,608

Business_Dispositions_Tables

Business Dispositions (Tables)	9 Months Ended
	Sep. 30, 2014
Business Dispositions [Abstract]	'
Schedule Of Discontinued Operation	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Revenue	$	-	$	10,964	$	14,439	$	25,396
	Loss before income taxes from discontinued operations	$	-1,053	$	-7,687	$	-18,393	$	-48,608
	Income tax (provision) benefit		-6		2,377		9,275		9,990
	Loss from discontinued operations, net of income taxes	$	-1,059	$	-5,310	$	-9,118	$	-38,618

Segment_Information_Tables

Segment Information (Tables)	9 Months Ended
	Sep. 30, 2014
Segment Information [Abstract]	'
Segment Reporting By Segment	'
		Three Months Ended				Nine Months Ended
		September 30,				September 30,
		2014		2013		2014		2013
	Dredging
	Contract revenues	$	167,079	$	155,469	$	486,153	$	465,915
	Operating income		5,733		13,129		24,157		46,698
	Environmental & remediation
	Contract revenues	$	37,182	$	36,114	$	79,224	$	53,215
	Operating income (loss)		2,274		800		-2,996		-6,643
	Intersegment revenues	$	-2,063	$	-3,721		-4,088		-3,990
	Total
	Contract revenues	$	202,198	$	187,862	$	561,289	$	515,140
	Operating income		8,007		13,929		21,161		40,055

Subsidiary_Guarantors_Tables

Subsidiary Guarantors (Tables)	9 Months Ended
	Sep. 30, 2014
Subsidiary Guarantors [Abstract]	'
Condensed Consolidating of Balance Sheet	'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING BALANCE SHEET
	AS OF SEPTEMBER 30, 2014
	(In thousands)
	ASSETS	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	CURRENT ASSETS:
	Cash and cash equivalents	$	18,212		$	2,873		$	3		$	-		$	21,088
	Accounts receivable — net		98,118			-			-			-			98,118
	Receivables from affiliates		164,731			3,561			33,406			-201,698			-
	Contract revenues in excess of billings		82,717			2,911			-			-			85,628
	Inventories		33,194			-			-			-			33,194
	Prepaid expenses and other current assets		60,207			875			-2,642			-			58,440
	Total current assets		457,179			10,220			30,767			-201,698			296,468
	PROPERTY AND EQUIPMENT—Net		382,325			6			-			-			382,331
	GOODWILL AND OTHER INTANGIBLE ASSETS—Net		80,885			-			-			-			80,885
	INVENTORIES — Noncurrent		37,324			-			-			-			37,324
	INVESTMENTS IN JOINT VENTURES		8,445			-			-			-			8,445
	INVESTMENTS IN SUBSIDIARIES		3,722			-			594,364			-598,086			-
	OTHER		7,409			3			4,333			-			11,745
	TOTAL	$	977,289		$	10,229		$	629,464		$	-799,784		$	817,198
	LIABILITIES AND EQUITY
	CURRENT LIABILITIES:
	Accounts payable	$	138,137		$	903		$	301		$	-		$	139,341
	Payables to affiliates		175,587			12,327			13,784			-201,698			-
	Accrued expenses		45,663			221			3,871			-			49,755
	Billings in excess of contract revenues		4,978			-			-			-			4,978
	Current portion of long term debt		373			-			-			-			373
	Total current liabilities		364,738			13,451			17,956			-201,698			194,447
	7 3/8% SENIOR NOTES		-			-			250,000			-			250,000
	REVOLVING CREDIT FACILITY		-			-			35,000			-			35,000
	LONG TERM NOTE PAYABLE		485			-			-			-			485
	DEFERRED INCOME TAXES		-363			-			90,403			-			90,040
	OTHER		11,121			-			551			-			11,672
	Total liabilities		375,981			13,451			393,910			-201,698			581,644
	Total Great Lakes Dredge & Dock Corporation Equity		601,308			-3,222			235,554			-598,086			235,554
	NONCONTROLLING INTERESTS		-			-			-			-			-
	TOTAL EQUITY		601,308			-3,222			235,554			-598,086			235,554
	TOTAL	$	977,289		$	10,229		$	629,464		$	-799,784		$	817,198
	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
Schedule Of Condensed Consolidating Operations And Comprehensive Income	'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2014
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	198,934		$	3,264		$	-		$	-		$	202,198
	Costs of contract revenues		-170,911			-6,828			-			-			-177,739
	Gross profit		28,023			-3,564			-			-			24,459
	OPERATING EXPENSES:
	General and administrative expenses		15,988			1			73			-			16,062
	Loss on sale of assets—net		390			-			-			-			390
	Operating income (loss)		11,645			-3,565			-73			-			8,007
	Interest expense—net		-60			-			-4,642			-			-4,702
	Equity in earnings of subsidiaries		54			-			3,316			-3,370			-
	Equity in loss of joint ventures		-5,785			-			-			-			-5,785
	Other income		384			-			-			-			384
	Income (loss) from continuing operations before income taxes		6,238			-3,565			-1,399			-3,370			-2,096
	Income tax benefit		697			-			372			-			1,069
	Income (loss) from continuing operations		6,935			-3,565			-1,027			-3,370			-1,027
	Loss from discontinued operations, net of income taxes		-1,059			-			-1,059			1,059			-1,059
	Net income (loss)		5,876			-3,565			-2,086			-2,311			-2,086
	Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	5,876		$	-3,565		$	-2,086		$	-2,311		$	-2,086
	Comprehensive income (loss) attributable to	$	5,707		$	-3,981		$	-2,671		$	-1,726		$	-2,671
	Great Lakes Dredge & Dock Corporation
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE THREE MONTHS ENDED SEPTEMBER 30, 2013
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	179,514		$	8,348		$	-		$	-		$	187,862
	Costs of contract revenues		-149,966			-10,060			-			-			-160,026
	Gross profit		29,548			-1,712			-			-			27,836
	OPERATING EXPENSES:
	General and administrative expenses		17,121			-			-			-			17,121
	Proceeds from loss of use claim		-			-			-			-			-
	Gain on sale of assets—net		-3,214			-			-			-			-3,214
	Operating income (loss)		15,641			-1,712			-			-			13,929
	Interest expense—net		-65			-71			-5,406			-			-5,542
	Equity in earnings of subsidiaries		304			-			12,711			-13,015			-
	Equity in earnings of joint ventures		1,427			-			-			-			1,427
	Other income (expense)		-187			9			-			-			-178
	Income (loss) from continuing operations before income taxes		17,120			-1,774			7,305			-13,015			9,636
	Income tax provision		-2,331			-			-729			-			-3,060
	Income (loss) from continuing operations		14,789			-1,774			6,576			-13,015			6,576
	Loss from discontinued operations, net of income taxes		-5,310			-198			-5,310			5,508			-5,310
	Net income (loss)		9,479			-1,972			1,266			-7,507			1,266
	Net loss attributable to noncontrolling interest		-			-			182			-			182
	Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation		9,479			-1,972			1,448			-7,507			1,448
	Comprehensive income (loss) attributable to	$	9,391		$	-2,023		$	1,309		$	-7,368		$	1,309
	Great Lakes Dredge & Dock Corporation
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
	FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2014
	(In thousands)
		Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
	Contract revenues	$	540,199		$	21,090		$	-		$	-		$	561,289
	Costs of contract revenues		-463,718			-26,002			-			-			-489,720
	Gross profit		76,481			-4,912			-			-			71,569
	OPERATING EXPENSES:
	General and administrative expenses		49,776			1			73			-			49,850
	Proceeds from loss of use claim		-			-			-			-			-
	Loss on sale of assets—net		558			-			-			-			558
Operating income (loss)		26,147			-4,913			-73			-			21,161
Interest expense—net		91			-261			-14,560			-			-14,730
Equity in earnings (loss) of subsidiaries		-52			-			15,915			-15,863			-
Equity in loss of joint ventures		-9,063			-			-			-			-9,063
Gain on bargain purchase acquisition		2,197			-			-			-			2,197
Other income		403			7			-			-			410
Income (loss) from continuing operations before income taxes		19,723			-5,167			1,282			-15,863			-25
Income tax (provision) benefit		1,307			-			-882			-			425
Income (loss) from continuing operations		21,030			-5,167			400			-15,863			400
Loss from discontinued operations, net of income taxes		-9,118			-1,343			-9,118			10,461			-9,118
Net income (loss)		11,912			-6,510			-8,718			-5,402			-8,718
Net (income) loss attributable to noncontrolling interest		-			-			-			-			-
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	11,912		$	-6,510		$	-8,718		$	-5,402		$	-8,718
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	$	11,713		$	-6,899		$	-9,306		$	-4,814		$	-9,306
GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
CONDENSED CONSOLIDATING STATEMENT OF OPERATIONS AND COMPREHENSIVE INCOME
FOR THE NINE MONTHS ENDED SEPTEMBER 30, 2013
(In thousands)
	Subsidiary Guarantors			Non-Guarantor Subsidiaries			GLDD Corporation			Eliminations			Consolidated Totals
Contract revenues	$	497,486		$	17,654		$	-		$	-		$	515,140
Costs of contract revenues		-422,764			-20,034			-			-			-442,798
Gross profit		74,722			-2,380			-			-			72,342
OPERATING EXPENSES:
General and administrative expenses		48,695			5			-			-			48,700
Proceeds from loss of use claim		-13,272			-			-			-			-13,272
Gain on sale of assets—net		-3,141			-			-			-			-3,141
Operating income (loss)		42,440			-2,385			-			-			40,055
Interest expense—net		-214			-160			-16,297			-			-16,671
Equity in earnings of subsidiaries		306			-			39,777			-40,083			-
Equity in earnings of joint ventures		452			-			-			-			452
Other expense		-55			-348			-			-			-403
Income (loss) from continuing operations before income taxes		42,929			-2,893			23,480			-40,083			23,433
Income tax (provision) benefit		45			2			-8,373			-			-8,326
Income (loss) from continuing operations		42,974			-2,891			15,107			-40,083			15,107
Loss from discontinued operations, net of income taxes		-38,618			-265			-38,618			38,883			-38,618
Net income (loss)		4,356			-3,156			-23,511			-1,200			-23,511
Net loss attributable to noncontrolling interest		-			-			151			-			151
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	$	4,356		$	-3,156		$	-23,360		$	-1,200		$	-23,360
Comprehensive income (loss) attributable to	$	4,234		$	-3,287		$	-23,613		$	-947		$	-23,613
Great Lakes Dredge & Dock Corporation
Condensed Cash Flow Statement	'
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE NINE MONTHS ENDED SEPTEMBER 30, 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		$	24,488		$	-3,357		$	-5,840		$	-		$	15,291
	Net cash flows used in operating activities of discontinued operations			-4,000			-1,024			-			-			-5,024
	Cash provided by (used in) operating activities			20,488			-4,381			-5,840			-			10,267
	INVESTING ACTIVITIES:
	Purchases of property and equipment			-66,433			-			-			-			-66,433
	Proceeds from dispositions of property and equipment			1,614			-			-			-			1,614
	Payments on vendor performance obligations			-3,100			-			-			-			-3,100
	Payments for acquisitions of businesses			-2,048			-			-			-			-2,048
	Net change in accounts with affiliates			-9,402			-			-			9,402			-
	Net cash flows used in investing activities of continuing operations			-79,369			-			-			9,402			-69,967
	Net cash flows provided by investing activities of discontinued operations			5,275			-			-			-			5,275
	Cash used in investing activities			-74,094			-			-			9,402			-64,692
	FINANCING ACTIVITIES:
	Deferred financing fees			-			-			-845			-			-845
	Taxes paid on settlement of vested share awards			-			-			-501			-			-501
	Repayments of equipment debt			-121			-			-			-			-121
	Purchase of noncontrolling interest			-			-			-205			-			-205
	Net change in accounts with affiliates			-			3,595			5,807			-9,402			-
	Exercise of options and purchases from employee stock plans			-			-			1,542			-			1,542
	Excess income tax benefit from share-based compensation			-			-			45			-			45
	Borrowings under revolving loans			-			-			105,000			-			105,000
	Repayments of revolving loans			-			-			-105,000			-			-105,000
	Net cash flows provided by (used in) financing activities of continuing operations			-121			3,595			5,843			-9,402			-85
	Net cash flows provided by (used in) financing activities of discontinued operations			-			-			-			-			-
	Cash provided by (used in) financing activities			-121			3,595			5,843			-9,402			-85
	Effect of foreign currency exchange rates on cash and cash equivalents			-			260			-			-			260
	Net increase (decrease) in cash and cash equivalents			-53,727			-526			3			-			-54,250
	Cash and cash equivalents at beginning of period			71,939			3,399			-			-			75,338
	Cash and cash equivalents at end of period		$	18,212		$	2,873		$	3		$	-		$	21,088
	GREAT LAKES DREDGE & DOCK CORPORATION AND SUBSIDIARIES
	CONDENSED CONSOLIDATING STATEMENT OF CASH FLOWS
	FOR THE NINE MONTHS ENDED SEPTEMBER 30, 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		$	47,543		$	-6,776		$	-29,542		$	-		$	11,225
	Net cash flows used in operating activities of discontinued operations			-8,054			-437			-			-			-8,491
	Cash provided by (used in) operating activities			39,489			-7,213			-29,542			-			2,734
	INVESTING ACTIVITIES:
	Purchases of property and equipment			-37,968			-			-			-			-37,968
	Proceeds from dispositions of property and equipment			4,194			-			-			-			4,194
	Proceeds from vendor performance obligations			13,600			-			-			-			13,600
	Net change in accounts with affiliates			-5,309			-			-			5,309			-
	Net cash flows used in investing activities of continuing operations			-25,483			-			-			5,309			-20,174
	Net cash flows used in investing activities of discontinued operations			-149			-			-			-			-149
	Cash used in investing activities			-25,632			-			-			5,309			-20,323
	FINANCING ACTIVITIES:
	Repayments of long term note payable			-			-			-10,547			-			-10,547
	Taxes paid on settlement of vested share awards			-			-			-305			-			-305
	Repayment of equipment debt			-6			-			-			-			-6
	Net change in accounts with affiliates			-			9,700			-4,391			-5,309			-
	Exercise of options and purchases from employee stock plans			-			-			581			-			581
	Excess income tax benefit from share-based compensation			-			-			133			-			133
	Borrowings under revolving loans			-			-			194,500			-			194,500
	Repayments of revolving loans			-			-			-149,500			-			-149,500
	Capital contributions			-			926			-926			-			-
	Net cash flows provided by (used in) financing activities of continuing operations			-6			10,626			29,545			-5,309			34,856
Net cash flows used in financing activities of discontinued operations			-36			-			-3			-			-39
Cash provided by (used in) financing activities			-42			10,626			29,542			-5,309			34,817
Effect of foreign currency exchange rates on cash and cash equivalents			-			-346			-			-			-346
Net increase in cash and cash equivalents			13,815			3,067			-			-			16,882
Cash and cash equivalents at beginning of period			24,272			168			-			-			24,440
Cash and cash equivalents at end of period		$	38,087		$	3,235		$	-		$	-		$	41,322

Basis_of_presentation_Narrativ

Basis of presentation (Narrative) (Details)	9 Months Ended	3 Months Ended
	Sep. 30, 2014	Sep. 30, 2014	Sep. 30, 2014
	segment	Maximum [Member]	Minimum [Member]
Basis of presentation [Line Items]	'	'	'
Average equipment-related costs of total costs of contract revenue	'	23.00%	22.00%
Number of reportable segments	2	'	'
Number of 0perating Segments	4	'	'

Earnings_per_share_Estimated_U

Earnings per share (Estimated Useful Lives By Class Of Assets) (Narrative) (Detail)	3 Months Ended	9 Months Ended
	Sep. 30, 2014	Sep. 30, 2014
Earnings Per Share Basic Line Items	'	'
Potentially dilutive stock options and restricted stock units	521	'
Treasury Stock [Member]	'	'
Earnings Per Share Basic Line Items	'	'
Potentially dilutive stock options and restricted stock units	664	500

Earnings_per_share_Computation

Earnings per share (Computations For Basic And Diluted Earnings Per Share) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, except Per Share data, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Earnings Per Share Basic Line Items	'	'	'	'
Income (loss) from continuing operations	($1,027)	$6,576	$400	$15,107
Loss on discontinued operations, net of income taxes, attributable to Great Lakes Dredge & Dock Corporation	-1,059	-5,128	-9,118	-38,467
Net loss attributable to common stockholders of Great Lakes Dredge & Dock	-2,086	1,448	-8,718	-23,360
Weighted-average common shares outstanding - basic	60,040	59,526	59,870	59,444
Effect of stock options and restricted stock units	'	556	621	556
Weighted-average common shares outstanding - diluted	60,040	60,082	60,491	60,000
Basic earnings (loss) per share attributable to continuing operations	($0.01)	$0.11	$0.01	$0.25
Diluted earnings (loss) per share attributable to continuing operations	($0.01)	$0.11	$0.01	$0.25
GLDD Corporation [Member]	'	'	'	'
Earnings Per Share Basic Line Items	'	'	'	'
Income (loss) from continuing operations	-1,027	6,576	400	15,107
Net loss attributable to common stockholders of Great Lakes Dredge & Dock	($2,086)	$1,448	($8,718)	($23,360)

Accounts_Receivable_And_Contra2

Accounts Receivable And Contracts In Progress (Schedule Of Accounts Receivable) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accounts Receivable [Line Items]	'	'
Retainage	$16,450	$18,506
Accounts Receivable, Gross	100,570	98,044
Allowance for doubtful accounts	-1,529	-1,529
Total accounts receivable-net	99,041	96,515
Current portion of accounts receivable-net	98,118	96,515
Long-term accounts receivable and retainage	923	'
Completed Contracts [Member]	'	'
Accounts Receivable [Line Items]	'	'
Contracts	12,718	17,361
Contracts In Progress [Member]	'	'
Accounts Receivable [Line Items]	'	'
Contracts	$71,402	$62,177

Accounts_Receivable_And_Contra3

Accounts Receivable And Contracts In Progress (Components Of Contracts In Progress) (Details) (USD $)	Sep. 30, 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	$77,034	$64,740
Costs and earnings in excess of billings for completed contracts	8,594	2,692
Total contract revenues in excess of billings	85,628	67,432
Total billings in excess of contract revenues	-4,978	-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	737,986	435,470
Amounts billed	-660,952	-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	-175,854	-156,794
Billings in excess of costs and earnings, Costs and earnings for contracts in progress	$170,876	$150,040

Accrued_Expenses_Details

Accrued Expenses (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Accrued Expenses [Abstract]	'	'
Insurance	$13,219	$8,649
Payroll and employee benefits	8,406	13,664
Income and other taxes	4,803	3,709
Interest	3,309	8,066
Percentage of completion adjustment	451	2,135
Other	19,567	2,308
Total accrued expenses	$49,755	$38,531

Longterm_debt_Narrative_Detail

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

9 Months Ended

9 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

0 Months Ended

9 Months Ended

Sep. 30, 2014

Dec. 31, 2013

Sep. 30, 2014

Sep. 15, 2014

Sep. 30, 2014

Jun. 04, 2012

Jun. 04, 2012

Jun. 04, 2012

Sep. 30, 2014

Dec. 31, 2013

Sep. 15, 2014

Sep. 30, 2014

Sep. 30, 2014

Sep. 15, 2014

Sep. 30, 2014

Sep. 30, 2014

item

Senior Notes [Member]

Terminated international Letter 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]

Maximum [Member]

Minimum [Member]

Minimum [Member]

Minimum [Member]

item

LIBOR Rate [Member]

Base Rate [Member]

item

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

'

'

'

'

'

$210,000,000

$50,000,000

$10,000,000

'

'

'

'

'

'

'

'

Line of Credit Facility, Amount Outstanding

35,000,000

35,000,000

'

'

35,000,000

'

'

'

35,000,000

35,000,000

'

'

'

'

'

'

Line of credit facility optional increase capacity

'

'

'

'

'

15,000,000

'

'

'

'

'

'

'

'

'

'

Revolving credit facility, interest rate description

'

'

'

'

'On September 15, 2014, the Company entered into the fifth amendment (the "Fifth Amendment") to the Credit Agreement which exercised a portion of the incremental loans feature of the Credit Agreement that allowed the Company to increase the aggregate revolving commitment. A new lender provided an incremental commitment of $35,000 increasing the aggregate revolving commitment to $210,000. Additionally, the Fifth Amendment allowed full use of the aggregate revolving commitment for the issuance of letters of credit and decreasing the required ratio of aggregate orderly liquidation value of pledged collateral from 1.5 times to 1.27 times the aggregate revolving commitment. The Fifth Amendment further amended the Credit Agreement to secured and collateralized by perfected liens on certain of the Company's vessels and its domestic accounts receivable, subject to permitted liens and prior interests of other parties. In connection with the Company's entry into the Fifth Amendment, Zurich American Insurance Company, the Company's surety provider, secured permitted second mortgages on the same vessels securing the obligations under the Credit Agreement.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%

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Revolving credit facility, basis spread on variable rate

'

'

'

'

'

'

'

'

'

'

'

2.50%

1.50%

'

1.50%

0.50%

Letters of credit outstanding

117,761,000

'

'

'

'

'

'

'

'

'

'

'

'

'

'

'

Percentage Of Debt Instrument Issued At Face Value

'

'

7.38%

'

'

'

'

'

'

'

'

'

'

'

'

'

Letter of credit remaining borrowing capacity

57,239,000

'

'

24,000

'

'

'

'

'

'

'

'

'

'

'

'

Debt instrument, face amount

'

'

$250,000

'

'

'

'

'

'

'

'

'

'

'

'

'

Stated interest rate

'

'

7.28%

'

'

'

'

'

'

'

'

'

'

'

'

'

Decreased required ratio of aggregate orderly liquidation value of pledged collateral

'

'

'

'

'

'

'

'

'

'

1.27

'

'

1.5

'

'

Fair_Value_Measurements_Narrat

Fair Value Measurements (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013	Jan. 31, 2011
			gal
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'
Derivative underlying hedge percent	'	'	80.00%	'	'	'
Derivative, Nonmonetary Notional Amount, Volume	'	'	4,100,000	'	'	'
Senior Notes	$250,000	'	$250,000	'	$250,000	$250,000
Reclassification of derivative losses (gains) to earnings-net of tax	306	53	332	-237	'	'
Fair value hedge liabilities	1,051	'	1,051	'	'	'
Senior notes interest rate	7.38%	'	7.38%	'	'	7.38%
Maximum [Member]	'	'	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'
Fixed price range	3.01	'	3.01	'	'	'
Minimum [Member]	'	'	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'
Fixed price range	2.86	'	2.86	'	'	'
Senior Notes [Member] | Fair Value, Inputs, Level 1 [Member]	'	'	'	'	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'	'	'	'	'
Senior Notes	$256,875	'	$256,875	'	'	'

Fair_Value_Measurements_Fair_V

Fair Value Measurements (Fair Value Measurements at Reporting Date Using) (Details) (Fuel Hedge Contracts [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Defined Benefit Plan Disclosure [Line Items]	'	'
Assets, fair value disclosure	'	$332
Liabilities, fair value disclosure	1,051	'
Fair Value, Inputs, Level 2 [Member]	'	'
Defined Benefit Plan Disclosure [Line Items]	'	'
Assets, fair value disclosure	'	332
Liabilities, fair value disclosure	$1,051	'

Fair_Value_Measurements_Accumu

Fair Value Measurements (Accumulated other comprehensive loss) (Details) (USD $)	3 Months Ended				9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014		Sep. 30, 2013		Sep. 30, 2014		Sep. 30, 2013
Derivatives, Fair Value [Line Items]	'		'		'		'
Cumulative translation adjustments-net of tax	($416)		($51)		($389)		($131)
Reclassification of derivative losses (gains) to earnings-net of tax	-306		-53		-332		237
Total other comprehensive income (loss)	136		-35		132		-359
Net unrealized (gain) loss on derivatives-net of tax (2)	-169	[1]	-88	[1]	-199	[1]	-122	[1]
Other comprehensive loss-net of tax	-585		-139		-588		-253
Costs of contract revenues	177,739		160,026		489,720		442,798
Income tax provision	-1,069		3,060		-425		8,326
Net income (loss)	-2,086		1,266		-8,718		-23,511
Fuel Hedge Contracts [Member]	'		'		'		'
Derivatives, Fair Value [Line Items]	'		'		'		'
Costs of contract revenues	-241		-88		-286		395
Income tax provision	65		-35		46		158
Net income (loss)	($306)		($53)		($332)		$237
[1]	Net of income tax expense of $111 and $58 for the three months ended September 30, 2014 and 2013, respectively, and $132 and $81 for the nine months ended September 30, 2014 and 2013, respectively.

Fair_Value_Measurements_Balanc

Fair Value Measurements (Balance Sheet Location) (Details) (Designated as Hedging Instrument [Member], Other Current Assets [Member], USD $)	Sep. 30, 2014	Dec. 31, 2013
In Thousands, unless otherwise specified
Designated as Hedging Instrument [Member] | Other Current Assets [Member]	'	'
Derivatives, Fair Value [Line Items]	'	'
Derivative asset, fair value, gross asset	'	$332
Derivative asset, fair value, gross liability	$1,051	'

ShareBased_Compensation_Narrat

Share-Based Compensation (Narrative) (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
In Thousands, except Share data, unless otherwise specified	31-May-14	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Options granted	337,000	'	'	'	'
Restricted stock units	182,000	'	'	'	'
Share-based compensation expense	'	$828	$1,000	$1,816	$2,452
Employees And Directors [Member]	'	'	'	'	'
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]	'	'	'	'	'
Share-based compensation arrangement by share-based payment award, number of shares available for grant	'	5,800,000	'	5,800,000	'

Commitments_And_Contingencies_

Commitments And Contingencies (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Jan. 31, 2011	Sep. 30, 2014	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2014	Sep. 30, 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	$117,761,000	'	'	'	'	'	'	'
Letter of credit remaining borrowing capacity	57,239,000	'	'	'	'	'	'	'
Senior notes interest rate	7.38%	'	7.38%	'	'	'	'	'
Bids bond range	'	'	'	'	'	'	10,000,000	1,000,000
Outstanding performance bonds	'	'	'	49,613,000	'	'	'	'
Revenue value remaining from outstanding performance bonds	603,748,000	'	'	'	'	'	'	'
Warranty periods	'	'	'	'	'	'	'3 years	'1 year
Senior Notes	$250,000,000	$250,000,000	$250,000,000	'	$250,000,000	$250,000,000	'	'

Investments_Investments_Under_

Investments (Investments Under the Equity Method) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
Investments [Abstract]	'	'
Equity Method Investment, Summarized Financial Information, Revenue	$5,853	$4,424
Equity Method Investment, Summarized Financial Information, Gross Profit (Loss)	-15,241	-714
Equity Method Investment, Summarized Financial Information, Net Income (Loss)	($16,110)	($1,608)

Business_Combinations_And_Disp

Business Combinations And Dispositions (Results Of Discontinued Operations) (Details) (USD $)	1 Months Ended	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Apr. 30, 2014	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Business Dispositions [Abstract]	'	'	'	'	'
Revenue	'	'	$10,964	$14,439	$25,396
Loss before income taxes from discontinued operations	'	-1,053	-7,687	-18,393	-48,608
Income tax benefit	'	-6	2,377	9,275	9,990
Loss from discontinued operations, net of income taxes	'	-1,059	-5,310	-9,118	-38,618
Proceeds from Divestiture of Businesses	$5,309	'	'	'	'

Segment_Information_Narrative_

Segment Information (Narrative) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
			segment
Segment Reporting Information [Line Items]	'	'	'	'
Contract revenues	$202,198	$187,862	$561,289	$515,140
Number of reportable segments	'	'	2	'
Dredging [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract revenues	167,079	155,469	486,153	465,915
Number of reportable segments	'	'	2	'
Demolition [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract revenues	37,182	36,114	79,224	53,215
Foreign [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract revenues	40,040	32,651	85,691	104,384
Intersegment Revenues [Member]	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'
Contract revenues	($2,063)	($3,721)	($4,088)	($3,990)

Segment_Information_Segment_Re

Segment Information (Segment Reporting By Segment) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013	Dec. 31, 2013
			segment
Segment Reporting Information [Line Items]	'	'	'	'	'
Contract revenues	$202,198	$187,862	$561,289	$515,140	'
Operating income (loss)	8,007	13,929	21,161	40,055	'
Depreciation and amortization	'	'	32,744	33,777	'
Total assets	817,198	'	817,198	'	852,645
Property and equipment - net	382,331	'	382,331	'	345,620
Investment in joint ventures	8,445	'	8,445	'	8,256
Number of Reportable Segments	'	'	2	'	'
GLDD Corporation [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Operating income (loss)	-73	'	-73	'	'
Total assets	629,464	'	629,464	'	676,831
Dredging [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Contract revenues	167,079	155,469	486,153	465,915	'
Operating income (loss)	5,733	13,129	24,157	46,698	'
Number of Reportable Segments	'	'	2	'	'
Demolition [Member]	'	'	'	'	'
Segment Reporting Information [Line Items]	'	'	'	'	'
Contract revenues	37,182	36,114	79,224	53,215	'
Operating income (loss)	$2,274	$800	($2,996)	($6,643)	'

Subsidiary_Guarantors_Narrativ

Subsidiary Guarantors (Narrative) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Dec. 31, 2013	Jan. 31, 2011
Senior Notes	$250,000	$250,000	$250,000
Senior notes interest rate	7.38%	'	7.38%
Owned Domestic Subsidiaries Percent	100.00%	'	'
GLDD Corporation [Member]	'	'	'
Senior Notes	$250,000	$250,000	'

Subsidiary_Guarantors_Condense

Subsidiary Guarantors (Condensed Consolidated Balance Sheets) (Details) (USD $)	Sep. 30, 2014	Dec. 31, 2013	Sep. 30, 2013	Dec. 31, 2012	Jan. 31, 2011
In Thousands, unless otherwise specified
ASSETS	'	'	'	'	'
Cash and cash equivalents	$21,088	$75,338	$41,322	$24,440	'
Accounts receivable-net	98,118	96,515	'	'	'
Contract revenues in excess of billings	85,628	67,432	'	'	'
Inventories	33,194	32,500	'	'	'
Prepaid expenses and other current assets	58,440	44,164	'	'	'
Assets held for sale, current	'	45,104	'	'	'
Total current assets	296,468	361,053	'	'	'
PROPERTY AND EQUIPMENT-Net	382,331	345,620	'	'	'
GOODWILL AND OTHER INTANGIBLE ASSETS-Net	80,885	81,302	'	'	'
INVENTORIES-Noncurrent	37,324	38,496	'	'	'
INVESTMENTS IN JOINT VENTURES	8,445	8,256	'	'	'
Assets held for sale, noncurrent	'	8,856	'	'	'
OTHER	11,745	9,062	'	'	'
TOTAL	817,198	852,645	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	139,341	116,121	'	'	'
Accrued expenses	49,755	38,531	'	'	'
Billings in excess of contract revenues	4,978	6,754	'	'	'
Liabilities held for sale	'	32,493	'	'	'
Current portion of long term debt	373	'	'	'	'
Total current liabilities	194,447	193,899	'	'	'
7 3/8% SENIOR NOTES	250,000	250,000	'	'	250,000
REVOLVING CREDIT FACILITY	35,000	35,000	'	'	'
LONG TERM NOTE PAYABLE	485	'	'	'	'
DEFERRED INCOME TAXES	90,040	108,511	'	'	'
LIABILITIES HELD FOR SALE-Noncurrent	'	1,212	'	'	'
OTHER	11,672	21,922	'	'	'
Total liabilities	581,644	610,544	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	235,554	242,946	'	'	'
NONCONTROLLING INTERESTS	'	-845	'	'	'
TOTAL EQUITY	235,554	242,101	252,519	273,425	'
TOTAL	817,198	852,645	'	'	'
Subsidiary Guarantors [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	18,212	71,939	38,087	24,272	'
Accounts receivable-net	98,118	95,476	'	'	'
Receivables from affiliates	164,731	131,984	'	'	'
Contract revenues in excess of billings	82,717	63,591	'	'	'
Inventories	33,194	32,500	'	'	'
Prepaid expenses and other current assets	60,207	23,549	'	'	'
Assets held for sale, current	'	41,763	'	'	'
Total current assets	457,179	460,802	'	'	'
PROPERTY AND EQUIPMENT-Net	382,325	345,612	'	'	'
GOODWILL AND OTHER INTANGIBLE ASSETS-Net	80,885	81,302	'	'	'
INVENTORIES-Noncurrent	37,324	38,496	'	'	'
INVESTMENTS IN JOINT VENTURES	8,445	8,256	'	'	'
INVESTMENTS IN SUBSIDIARIES	3,722	1,212	'	'	'
Assets held for sale, noncurrent	'	8,796	'	'	'
OTHER	7,409	3,886	'	'	'
TOTAL	977,289	948,362	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	138,137	115,235	'	'	'
Payables to affiliates	175,587	96,270	'	'	'
Accrued expenses	45,663	28,086	'	'	'
Billings in excess of contract revenues	4,978	6,754	'	'	'
Liabilities held for sale	'	38,158	'	'	'
Current portion of long term debt	373	'	'	'	'
Total current liabilities	364,738	284,503	'	'	'
LONG TERM NOTE PAYABLE	485	'	'	'	'
DEFERRED INCOME TAXES	-363	'	'	'	'
LIABILITIES HELD FOR SALE-Noncurrent	'	1,212	'	'	'
OTHER	11,121	21,679	'	'	'
Total liabilities	375,981	307,394	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	601,308	640,968	'	'	'
TOTAL EQUITY	601,308	640,968	'	'	'
TOTAL	977,289	948,362	'	'	'
Non-Guarantor Subsidiaries [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	2,873	3,399	3,235	168	'
Accounts receivable-net	'	1,039	'	'	'
Receivables from affiliates	3,561	7,337	'	'	'
Contract revenues in excess of billings	2,911	3,841	'	'	'
Prepaid expenses and other current assets	875	137	'	'	'
Assets held for sale, current	'	11,877	'	'	'
Total current assets	10,220	27,630	'	'	'
PROPERTY AND EQUIPMENT-Net	6	8	'	'	'
Assets held for sale, noncurrent	'	60	'	'	'
OTHER	3	3	'	'	'
TOTAL	10,229	27,701	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	903	754	'	'	'
Payables to affiliates	12,327	24,862	'	'	'
Accrued expenses	221	15	'	'	'
Liabilities held for sale	'	2,871	'	'	'
Total current liabilities	13,451	28,502	'	'	'
Total liabilities	13,451	28,502	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	-3,222	-801	'	'	'
TOTAL EQUITY	-3,222	-801	'	'	'
TOTAL	10,229	27,701	'	'	'
GLDD Corporation [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Cash and cash equivalents	3	'	'	'	'
Receivables from affiliates	33,406	12,205	'	'	'
Prepaid expenses and other current assets	-2,642	20,478	'	'	'
Total current assets	30,767	32,683	'	'	'
INVESTMENTS IN SUBSIDIARIES	594,364	638,955	'	'	'
OTHER	4,333	5,193	'	'	'
TOTAL	629,464	676,831	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Accounts payable	301	132	'	'	'
Payables to affiliates	13,784	30,394	'	'	'
Accrued expenses	3,871	10,430	'	'	'
Total current liabilities	17,956	40,956	'	'	'
7 3/8% SENIOR NOTES	250,000	250,000	'	'	'
REVOLVING CREDIT FACILITY	35,000	35,000	'	'	'
DEFERRED INCOME TAXES	90,403	108,531	'	'	'
OTHER	551	243	'	'	'
Total liabilities	393,910	434,730	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	235,554	242,946	'	'	'
NONCONTROLLING INTERESTS	'	-845	'	'	'
TOTAL EQUITY	235,554	242,101	'	'	'
TOTAL	629,464	676,831	'	'	'
Eliminations [Member]	'	'	'	'	'
ASSETS	'	'	'	'	'
Receivables from affiliates	-201,698	-151,526	'	'	'
Assets held for sale, current	'	-8,536	'	'	'
Total current assets	-201,698	-160,062	'	'	'
INVESTMENTS IN SUBSIDIARIES	-598,086	-640,167	'	'	'
OTHER	'	-20	'	'	'
TOTAL	-799,784	-800,249	'	'	'
LIABILITIES AND EQUITY	'	'	'	'	'
Payables to affiliates	-201,698	-151,526	'	'	'
Liabilities held for sale	'	-8,536	'	'	'
Total current liabilities	-201,698	-160,062	'	'	'
DEFERRED INCOME TAXES	'	-20	'	'	'
Total liabilities	-201,698	-160,082	'	'	'
EQUITY:	'	'	'	'	'
Total Great Lakes Dredge & Dock Corporation equity	-598,086	-640,167	'	'	'
TOTAL EQUITY	-598,086	-640,167	'	'	'
TOTAL	($799,784)	($800,249)	'	'	'

Subsidiary_Guarantors_Condense1

Subsidiary Guarantors (Condensed Consolidated Statement Operations And Comprehensive Income) (Details) (USD $)	3 Months Ended		9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013	Sep. 30, 2014	Sep. 30, 2013
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Contract revenues	$202,198	$187,862	$561,289	$515,140
Costs of contract revenues	-177,739	-160,026	-489,720	-442,798
Gross profit	24,459	27,836	71,569	72,342
General and administrative expenses	16,062	17,121	49,850	48,700
Proceeds from loss of use claim	'	'	'	13,272
Loss on sale of assets-net	390	-3,214	558	-3,141
Operating income (loss)	8,007	13,929	21,161	40,055
Interest expense-net	-4,702	-5,542	-14,730	-16,671
Equity in earnings (loss) of joint ventures	-5,785	1,427	-9,063	452
Gain on bargain purchase acquisition	'	'	2,197	'
Other income (expense)	384	-178	410	-403
Income (loss) from continuing operations before income taxes	-2,096	'	-25	'
Income (loss) from continuing operations before income taxes	-2,096	9,636	-25	23,433
Income tax (provision) benefit	1,069	-3,060	425	-8,326
Income (loss) from continuing operations	-1,027	6,576	400	15,107
Loss from discontinued operations, net of income taxes	-1,059	-5,310	-9,118	-38,618
Net loss	-2,086	1,266	-8,718	-23,511
Net loss attributable to noncontrolling interest	'	-182	'	-151
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-2,086	1,448	-8,718	-23,360
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-2,671	1,309	-9,306	-23,613
Subsidiary Guarantors [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Contract revenues	198,934	179,514	540,199	497,486
Costs of contract revenues	-170,911	-149,966	-463,718	-422,764
Gross profit	28,023	29,548	76,481	74,722
General and administrative expenses	15,988	17,121	49,776	48,695
Proceeds from loss of use claim	'	'	'	13,272
Loss on sale of assets-net	390	-3,214	558	-3,141
Operating income (loss)	11,645	15,641	26,147	42,440
Interest expense-net	-60	-65	91	-214
Equity in earnings (loss) of subsidiaries	54	304	-52	306
Equity in earnings (loss) of joint ventures	-5,785	1,427	-9,063	452
Gain on bargain purchase acquisition	'	'	2,197	'
Other income (expense)	384	-187	403	-55
Income (loss) from continuing operations before income taxes	6,238	'	19,723	'
Income (loss) from continuing operations before income taxes	'	17,120	'	42,929
Income tax (provision) benefit	697	-2,331	1,307	45
Income (loss) from continuing operations	6,935	14,789	21,030	42,974
Loss from discontinued operations, net of income taxes	-1,059	-5,310	-9,118	-38,618
Net loss	5,876	9,479	11,912	4,356
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	5,876	9,479	11,912	4,356
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	5,707	9,391	11,713	4,234
Non-Guarantor Subsidiaries [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Contract revenues	3,264	8,348	21,090	17,654
Costs of contract revenues	-6,828	-10,060	-26,002	-20,034
Gross profit	-3,564	-1,712	-4,912	-2,380
General and administrative expenses	1	'	1	5
Operating income (loss)	-3,565	-1,712	-4,913	-2,385
Interest expense-net	'	-71	-261	-160
Other income (expense)	'	9	7	-348
Income (loss) from continuing operations before income taxes	-3,565	'	-5,167	'
Income (loss) from continuing operations before income taxes	'	-1,774	'	-2,893
Income tax (provision) benefit	'	'	'	2
Income (loss) from continuing operations	-3,565	-1,774	-5,167	-2,891
Loss from discontinued operations, net of income taxes	'	-198	-1,343	-265
Net loss	-3,565	-1,972	-6,510	-3,156
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-3,565	-1,972	-6,510	-3,156
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-3,981	-2,023	-6,899	-3,287
GLDD Corporation [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
General and administrative expenses	73	'	73	'
Operating income (loss)	-73	'	-73	'
Interest expense-net	-4,642	-5,406	-14,560	-16,297
Equity in earnings (loss) of subsidiaries	3,316	12,711	15,915	39,777
Income (loss) from continuing operations before income taxes	-1,399	'	1,282	'
Income (loss) from continuing operations before income taxes	'	7,305	'	23,480
Income tax (provision) benefit	372	-729	-882	-8,373
Income (loss) from continuing operations	-1,027	6,576	400	15,107
Loss from discontinued operations, net of income taxes	-1,059	-5,310	-9,118	-38,618
Net loss	-2,086	1,266	-8,718	-23,511
Net loss attributable to noncontrolling interest	'	-182	'	-151
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-2,086	1,448	-8,718	-23,360
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	-2,671	1,309	-9,306	-23,613
Eliminations [Member]	'	'	'	'
Condensed Financial Statements, Captions [Line Items]	'	'	'	'
Equity in earnings (loss) of subsidiaries	-3,370	-13,015	-15,863	-40,083
Income (loss) from continuing operations before income taxes	-3,370	'	-15,863	'
Income (loss) from continuing operations before income taxes	'	-13,015	'	-40,083
Income (loss) from continuing operations	-3,370	-13,015	-15,863	-40,083
Loss from discontinued operations, net of income taxes	1,059	5,508	10,461	38,883
Net loss	-2,311	-7,507	-5,402	-1,200
Net income (loss) attributable to common stockholders of Great Lakes Dredge & Dock Corporation	-2,311	-7,507	-5,402	-1,200
Comprehensive income (loss) attributable to Great Lakes Dredge & Dock Corporation	($1,726)	($7,368)	($4,814)	($947)

Subsidiary_Guarantors_Condense2

Subsidiary Guarantors (Condensed Consolidated of Cash Flow) (Details) (USD $)	9 Months Ended
In Thousands, unless otherwise specified	Sep. 30, 2014	Sep. 30, 2013
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	$15,291	$11,225
Net cash flows used in operating activities of discontinued operations	-5,024	-8,491
Cash provided by operating activities	10,267	2,734
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-66,433	-37,968
Proceeds from dispositions of property and equipment	1,614	4,194
Payments to Acquire Business Two, Net of Cash Acquired	2,048	'
Payments on vendor performance obligations	-3,100	13,600
Net cash flows used in investing activities of continuing operations	-69,967	-20,174
Net cash flows provided by investing activities of discontinued operations	5,275	-149
Cash used in investing activities	-64,692	-20,323
FINANCING ACTIVITIES:	'	'
Deferred financing fees	-845	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	-501	-305
Repayments of equipment debt	-121	-6
Purchase of noncontrolling interest	-205	'
Exercise of options and purchases from employee stock plans	1,542	581
Excess income tax benefit from share-based compensation	45	133
Borrowings under revolving loans	105,000	194,500
Repayments of revolving loans	-105,000	-149,500
Net cash flows provided by (used in) financing activities of continuing operations	-85	34,856
Net cash flows provided by (used in) financing activities of discontinued operations	'	-39
Cash provided by (used in) financing activities	-85	34,817
Effect of foreign currency exchange rates on cash and cash equivalents	260	-346
Net increase (decrease) in cash and cash equivalents	-54,250	16,882
Cash and cash equivalents at beginning of period	75,338	24,440
Cash and cash equivalents at end of period	21,088	41,322
Subsidiary Guarantors [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	24,488	47,543
Net cash flows used in operating activities of discontinued operations	-4,000	-8,054
Cash provided by operating activities	20,488	39,489
INVESTING ACTIVITIES:	'	'
Purchases of property and equipment	-66,433	-37,968
Proceeds from dispositions of property and equipment	1,614	4,194
Payments to Acquire Business Two, Net of Cash Acquired	2,048	'
Payments on vendor performance obligations	-3,100	13,600
Net change in accounts with affiliates	-9,402	-5,309
Net cash flows used in investing activities of continuing operations	-79,369	-25,483
Net cash flows provided by investing activities of discontinued operations	5,275	-149
Cash used in investing activities	-74,094	-25,632
FINANCING ACTIVITIES:	'	'
Repayments of equipment debt	-121	'
Net cash flows provided by (used in) financing activities of continuing operations	-121	-6
Net cash flows provided by (used in) financing activities of discontinued operations	'	-36
Cash provided by (used in) financing activities	-121	-42
Net increase (decrease) in cash and cash equivalents	-53,727	13,815
Cash and cash equivalents at beginning of period	71,939	24,272
Cash and cash equivalents at end of period	18,212	38,087
Non-Guarantor Subsidiaries [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	-3,357	-6,776
Net cash flows used in operating activities of discontinued operations	-1,024	-437
Cash provided by operating activities	-4,381	-7,213
FINANCING ACTIVITIES:	'	'
Net change in accounts with affiliates, in finance activities	3,595	9,700
Capital contributions	'	926
Net cash flows provided by (used in) financing activities of continuing operations	3,595	10,626
Cash provided by (used in) financing activities	3,595	10,626
Effect of foreign currency exchange rates on cash and cash equivalents	260	-346
Net increase (decrease) in cash and cash equivalents	-526	3,067
Cash and cash equivalents at beginning of period	3,399	168
Cash and cash equivalents at end of period	2,873	3,235
GLDD Corporation [Member]	'	'
OPERATING ACTIVITIES:	'	'
Net cash flows provided by (used in) operating activities of continuing operations	-5,840	-29,542
Cash provided by operating activities	-5,840	-29,542
FINANCING ACTIVITIES:	'	'
Deferred financing fees	-845	'
Repayment of long term note payable	'	-10,547
Taxes paid on settlement of vested share awards	-501	-305
Purchase of noncontrolling interest	-205	'
Exercise of options and purchases from employee stock plans	1,542	581
Excess income tax benefit from share-based compensation	45	133
Net change in accounts with affiliates, in finance activities	5,807	-4,391
Borrowings under revolving loans	105,000	194,500
Repayments of revolving loans	-105,000	-149,500
Capital contributions	'	-926
Net cash flows provided by (used in) financing activities of continuing operations	5,843	29,545
Net cash flows provided by (used in) financing activities of discontinued operations	'	-3
Cash provided by (used in) financing activities	5,843	29,542
Net increase (decrease) in cash and cash equivalents	3	'
Cash and cash equivalents at end of period	3	'
Eliminations [Member]	'	'
INVESTING ACTIVITIES:	'	'
Net change in accounts with affiliates	9,402	5,309
Net cash flows used in investing activities of continuing operations	9,402	5,309
Cash used in investing activities	9,402	5,309
FINANCING ACTIVITIES:	'	'
Net change in accounts with affiliates, in finance activities	-9,402	-5,309
Net cash flows provided by (used in) financing activities of continuing operations	-9,402	-5,309
Cash provided by (used in) financing activities	($9,402)	($5,309)