Entity Central Index Key Costs and earnings in excess of billings for contracts in progress. Costs and earnings in excess of billings for completed contracts. Document and entity information. Document And Entity Information [Abstract] Document Type Document Type Amendment Flag Amendment Flag Document Period End Date Document Period End Date Document Fiscal Year Focus Document Fiscal Year Focus Document Fiscal Period Focus Document Fiscal Period Focus Trading Symbol Trading Symbol Entity Registrant Name Entity Registrant Name Entity Central Index Key Current Fiscal Year End Date Current Fiscal Year End Date Entity Filer Category Entity Filer Category Entity Shell Company Entity Shell Company Entity Small Business Entity Small Business Entity Emerging Growth Company Entity Emerging Growth Company Entity Address, Address Line One Entity Address Address Line1 Entity Address, City or Town Entity Address City Or Town Entity Address, State or Province Entity Address State Or Province Entity Address, Country Entity Address Country Entity Common Stock, Shares Outstanding Entity Common Stock Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Entity File Number Entity File Number Entity Tax Identification Number Entity Tax Identification Number City Area Code City Area Code Local Phone Number Local Phone Number Entity Address, Postal Zip Code Entity Address Postal Zip Code Statement Of Financial Position [Abstract] ASSETS Assets [Abstract] CURRENT ASSETS: Assets Current [Abstract] Cash and cash equivalents Cash And Cash Equivalents At Carrying Value Accounts receivable—net Accounts Receivable Net Current Contract revenues in excess of billings Contract Receivable Due One Year Or Less Inventories Inventory Net Prepaid expenses and other current assets Prepaid Expense And Other Assets Current Assets held for sale Assets Of Disposal Group Including Discontinued Operation Current Total current assets Assets Current PROPERTY AND EQUIPMENT—Net Property Plant And Equipment Net OPERATING LEASE ASSETS Operating Lease Right Of Use Asset GOODWILL AND OTHER INTANGIBLE ASSETS—Net Intangible Assets Net Including Goodwill INVENTORIES—Noncurrent Inventory Noncurrent OTHER Other Assets Noncurrent TOTAL Assets LIABILITIES AND EQUITY Liabilities And Stockholders Equity [Abstract] Accounts payable Accounts Payable Current Accrued expenses Accrued Liabilities Current Operating lease liabilities Operating Lease Liability Current Billings in excess of contract revenues Contract With Customer Liability Current Revolving credit facility Lines Of Credit Current Liabilities held for sale Liabilities Of Disposal Group Including Discontinued Operation Current Total current liabilities Liabilities Current LONG-TERM DEBT Long Term Debt Noncurrent OPERATING LEASE LIABILITIES—Noncurrent Operating Lease Liability Noncurrent DEFERRED INCOME TAXES Deferred Tax Liabilities Noncurrent OTHER Other Liabilities Noncurrent Total liabilities Liabilities COMMITMENTS AND CONTINGENCIES (Note 10) Commitments And Contingencies EQUITY: Stockholders Equity [Abstract] Common stock—$.0001 par value; 90,000 authorized, 63,769 and 62,830 shares issued; 63,769 and 62,552 shares outstanding at June 30, 2019 and December 31, 2018, respectively. Common Stock Value Treasury stock, at cost Treasury Stock Value Additional paid-in capital Additional Paid In Capital Common Stock Accumulated deficit Retained Earnings Accumulated Deficit Accumulated other comprehensive loss Accumulated Other Comprehensive Income Loss Net Of Tax Total equity Stockholders Equity TOTAL Liabilities And Stockholders Equity Common stock, par value Common Stock Par Or Stated Value Per Share Common stock, shares authorized Common Stock Shares Authorized Common stock, shares issued Common Stock Shares Issued Common stock, shares outstanding Common Stock Shares Outstanding Income Statement [Abstract] Contract revenues Revenue From Contract With Customer Excluding Assessed Tax Type of Revenue [Extensible List] Type Of Revenue Extensible List Costs of contract revenues Cost Of Goods And Services Sold Type of Cost, Good or Service [Extensible List] Type Of Cost Good Or Service Extensible List Gross profit Gross Profit General and administrative expenses General And Administrative Expense (Gain) loss on sale of assets—net Gains Losses On Sales Of Assets Operating income Operating Income Loss Interest expense—net Interest Income Expense Nonoperating Net Other income (expense) Other Nonoperating Income Expense Income (loss) from continuing operations before income taxes Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest Income tax (provision) benefit Income Tax Expense Benefit Income (loss) from continuing operations Income Loss From Continuing Operations Loss from discontinued operations, net of income taxes Income Loss From Discontinued Operations Net Of Tax Net income (loss) Net Income Loss Basic earnings (loss) per share attributable to continuing operations Income Loss From Continuing Operations Per Basic Share Basic loss per share attributable to discontinued operations, net of tax Income Loss From Discontinued Operations Net Of Tax Per Basic Share Basic earnings (loss) per share Earnings Per Share Basic Basic weighted average shares Weighted Average Number Of Shares Outstanding Basic Diluted earnings (loss) per share attributable to continuing operations Income Loss From Continuing Operations Per Diluted Share Diluted loss per share attributable to discontinued operations, net of tax Income Loss From Discontinued Operations Net Of Tax Per Diluted Share Diluted earnings (loss) per share Earnings Per Share Diluted Diluted weighted average shares Weighted Average Number Of Diluted Shares Outstanding Statement Of Income And Comprehensive Income [Abstract] Net income (loss) Currency translation adjustment—net of tax Other Comprehensive Income Foreign Currency Transaction And Translation Gain Loss Arising During Period Net Of Tax Net change in cash flow derivative hedges—net of tax Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification And Tax Other comprehensive income (loss)—net of tax Other Comprehensive Income Loss Net Of Tax Comprehensive income (loss) Comprehensive Income Net Of Tax Currency translation adjustment, tax Other Comprehensive Income Foreign Currency Translation Gain Loss Arising During Period Tax Net change in cash flow derivative hedges, tax Other Comprehensive Income Loss Cash Flow Hedge Gain Loss After Reclassification Tax Vesting of restricted stock units value including impact of shares withheld for taxes. Vesting of restricted stock units shares including impact of shares withheld for taxes. Statement Of Stockholders Equity [Abstract] Statement [Table] Statement [Table] Equity Components Statement Equity Components [Axis] Equity Component Equity Component [Domain] Common Stock [Member] Common Stock [Member] Treasury Stock [Member] Treasury Stock [Member] Additional Paid-In Capital [Member] Additional Paid In Capital [Member] Accumulated Deficit [Member] Retained Earnings [Member] Accumulated Other Comprehensive Income (Loss) [Member] Accumulated Other Comprehensive Income [Member] Statement [Line Items] Statement [Line Items] BALANCE - value BALANCE - shares Shares Outstanding Cumulative effect of recent accounting pronouncements Cumulative Effect On Retained Earnings Tax1 Share-based compensation, value Stock Issued During Period Value Share Based Compensation Share-based compensation, shares Stock Issued During Period Shares Share Based Compensation Vesting of restricted stock units, including impact of shares withheld for taxes, value Vesting Of Restricted Stock Units Value Including Impact Of Shares Withheld For Taxes Vesting of restricted stock units, including impact of shares withheld for taxes, shares Vesting Of Restricted Stock Units Shares Including Impact Of Shares Withheld For Taxes Exercise of options and purchases from employee stock plans, value Stock Issued During Period Value Stock Options Exercised Exercise of options and purchases from employee stock plans, shares Stock Issued During Period Shares Stock Options Exercised Cancellation of treasury stock Treasury Stock Retired Cost Method Amount Cancellation of treasury stock, shares Treasury Stock Shares Retired Other comprehensive income—net of tax BALANCE - value BALANCE - shares Other non-cash restructuring items. Amortization of deferred financing cost and other non cash interest expense. Increase decrease in costs in excess of billings on uncompleted contracts or programs expected to be collected within one year. Statement Of Cash Flows [Abstract] OPERATING ACTIVITIES: Net Cash Provided By Used In Operating Activities [Abstract] Net income (loss) Profit Loss Adjustments to reconcile net income (loss) to net cash flows provided by operating activities: Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Depreciation and amortization Depreciation Depletion And Amortization Deferred income taxes Deferred Income Tax Expense Benefit (Gain) loss on sale of assets Other non-cash restructuring items Other Non Cash Restructuring Items Amortization of deferred financing fees Amortization Of Deferred Financing Cost And Other Non Cash Interest Expense Unrealized foreign currency gain Foreign Currency Transaction Gain Loss Unrealized Share-based compensation expense Share Based Compensation Changes in assets and liabilities: Increase Decrease In Operating Capital [Abstract] Accounts receivable Increase Decrease In Accounts Receivable Contract revenues in excess of billings Increase Decrease In Costs In Excess Of Billings On Uncompleted Contracts Or Programs Expected To Be Collected Within One Year Inventories Increase Decrease In Inventories Prepaid expenses and other current assets Increase Decrease In Prepaid Deferred Expense And Other Assets Accounts payable and accrued expenses Increase Decrease In Accounts Payable And Accrued Liabilities Billings in excess of contract revenues Increase Decrease In Contract With Customer Liability Other noncurrent assets and liabilities Increase Decrease In Other Noncurrent Assets And Liabilities Net Net cash flows provided by operating activities from continuing operations Net Cash Provided By Used In Operating Activities Continuing Operations Net cash flows used in operating activities of discontinued operations Cash Provided By Used In Operating Activities Discontinued Operations Cash provided by operating activities Net Cash Provided By Used In Operating Activities INVESTING ACTIVITIES: Net Cash Provided By Used In Investing Activities [Abstract] Purchases of property and equipment Payments To Acquire Property Plant And Equipment Proceeds from dispositions of property and equipment Proceeds From Sale Of Property Plant And Equipment Net cash flows used in investing activities of continuing operations Net Cash Provided By Used In Investing Activities Continuing Operations Net cash flows provided by investing activities of discontinued operations Cash Provided By Used In Investing Activities Discontinued Operations Cash used in investing activities Net Cash Provided By Used In Investing Activities Non cash repayments of debt with proceeds from sale leaseback transactions. FINANCING ACTIVITIES: Net Cash Provided By Used In Financing Activities [Abstract] Deferred financing fees Payment Of Financing And Stock Issuance Costs Repayments of debt Repayments Of Debt Taxes paid on settlement of vested share awards Payments Related To Tax Withholding For Share Based Compensation Exercise of options and purchases from employee stock plans Proceeds From Stock Options Exercised Borrowings under revolving loans Proceeds From Long Term Lines Of Credit Repayments of revolving loans Repayments Of Long Term Lines Of Credit Net cash flows used in financing activities of continuing operations Net Cash Provided By Used In Financing Activities Continuing Operations Net cash flows used in financing activities of discontinued operations Cash Provided By Used In Financing Activities Discontinued Operations Cash used in financing activities Net Cash Provided By Used In Financing Activities Effect of foreign currency exchange rates on cash and cash equivalents Effect Of Exchange Rate On Cash And Cash Equivalents Net increase (decrease) in cash, cash equivalents and restricted cash Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect Cash, cash equivalents and restricted cash at beginning of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations Cash, cash equivalents and restricted cash at end of period Restricted cash included in other long-term assets Restricted Cash Noncurrent Cash, cash equivalents and restricted cash at end of period Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Supplemental Cash Flow Information Supplemental Cash Flow Information [Abstract] Cash paid for interest Interest Paid Net Cash paid for income taxes Income Taxes Paid Net Non-cash Investing and Financing Activities Cash Flow Noncash Investing And Financing Activities Disclosure [Abstract] Property and equipment purchased but not yet paid Capital Expenditures Incurred But Not Yet Paid Repayments of debt with proceeds from sale-leaseback transactions Non Cash Repayments Of Debt With Proceeds From Sale Leaseback Transactions Organization Consolidation And Presentation Of Financial Statements [Abstract] Basis of Presentation Basis Of Presentation And Significant Accounting Policies [Text Block] Earnings Per Share [Abstract] Earnings Per Share Earnings Per Share [Text Block] Leases [Abstract] Leases Lessee Operating Leases [Text Block] Payables And Accruals [Abstract] Accrued Expenses Accounts Payable And Accrued Liabilities Disclosure [Text Block] Debt Disclosure [Abstract] Long-Term Debt Long Term Debt [Text Block] Fair Value Disclosures [Abstract] Fair Value Measurements Fair Value Disclosures [Text Block] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Share-Based Compensation Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Revenue From Contract With Customer [Abstract] Revenue Revenue From Contract With Customer [Text Block] Restructuring And Related Activities [Abstract] Restructuring Charges Restructuring And Related Activities Disclosure [Text Block] Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Commitments And Contingencies Disclosure [Text Block] Discontinued Operations And Disposal Groups [Abstract] Business Dispositions Disposal Groups Including Discontinued Operations Disclosure [Text Block] Recent Accounting Pronouncements New Accounting Pronouncements Policy Policy [Text Block] Computations for Basic and Diluted Earnings (Loss) Per Share Schedule Of Earnings Per Share Basic And Diluted Table [Text Block] Schedule of Stock Options and Restricted Stock Units Excluded from Diluted Weighted-Average Common Shares Schedule Of Weighted Average Number Of Shares Table [Text Block] Schedule of Stock Options and Restricted Stock Units Excluded from Calculation of Anti-Diluted Earnings Per Share Schedule Of Antidilutive Securities Excluded From Computation Of Earnings Per Share [Text Block] Schedule of Lease Costs Lease Cost Table [Text Block] Schedule of Maturity Analysis of Operating Lease Liabilities Lessee Operating Lease Liability Maturity Table [Text Block] Future Minimum Operating Lease Payments Operating Leases Of Lessee Disclosure [Text Block] Schedule of additional information related to leases. Schedule of Additional Information Related to Leases Schedule Of Additional Information Related To Leases Table [Text Block] Supplemental information related to leases. Supplemental Information Related to Leases Supplemental Information Related To Leases Table [Text Block] Accrued Expenses Schedule Of Accrued Liabilities Table [Text Block] Schedule of fair values of financial instruments and non-financial assets and liabilities measured. Schedule of Fair Values of Financial Instruments and Nonfinancial Assets and Liabilities Measured at the Reporting Date Schedule Of Fair Values Of Financial Instruments And Nonfinancial Assets And Liabilities Measured Table [Text Block] Schedule of Fair Value of Fuel Hedge Contracts Balance Sheet Location Fair Value By Balance Sheet Grouping [Text Block] Changes in Components of Accumulated Other Comprehensive Income (Loss) Schedule Of Accumulated Other Comprehensive Income Loss Table [Text Block] Adjustments Reclassified from Accumulated Balances Other Comprehensive Income (Loss) to Earnings Reclassification Out Of Accumulated Other Comprehensive Income Table [Text Block] Summary of Contract Revenues by Type of Work and Customer Disaggregation Of Revenue Table [Text Block] Schedule of Accounts Receivable Schedule Of Accounts Notes Loans And Financing Receivable [Text Block] Components of Contracts in Progress Costs In Excess Of Billings And Billings In Excess Of Costs Table [Text Block] Schedule of Restructuring Charges Schedule Of Restructuring And Related Costs [Text Block] Schedule of Discontinued Operations Schedule Of Disposal Groups Including Discontinued Operations Income Statement Balance Sheet And Additional Disclosures [Text Block] Schedule of Major Classes of Assets and Liabilities of Businesses Reported as Discontinued Operations Schedule Of Recognized Identified Assets Acquired And Liabilities Assumed Table [Text Block] Organization consolidation and presentation. Organization consolidation and presentation. Organization Consolidation And Presentation [Table] Organization Consolidation And Presentation [Table] Adjustments for New Accounting Pronouncements Adjustments For New Accounting Pronouncements [Axis] Type of Adoption Type Of Adoption [Member] Accounting Standards Update 2016-02 [Member] Accounting Standards Update201602 [Member] Organization Consolidation and Presentation [Line Items] Organization Consolidation And Presentation [Line Items] Cumulative net adjustment to the beginning retained earnings balance New Accounting Pronouncement Or Change In Accounting Principle Cumulative Effect Of Change On Equity Or Net Assets1 Number of reportable segments with goodwill. Number of operating Segments Number Of Operating Segments Number of reportable segments Number Of Reportable Segments Number of reportable segment with goodwill Number Of Reportable Segments With Goodwill Income (loss) from continuing operations Loss from discontinued operations, net of income taxes Weighted-average common shares outstanding — basic Effect of stock options and restricted stock units Weighted Average Number Diluted Shares Outstanding Adjustment Weighted-average common shares outstanding — diluted Earnings (loss) per share from continuing operations — basic Earnings (loss) per share from continuing operations — diluted Securities excluded from computation of earnings per share amount due to loss. Effect of stock options and restricted stock units Securities Excluded From Computation Of Earnings Per Share Amount Due To Loss Effect of stock options and restricted stock units Antidilutive Securities Excluded From Computation Of Earnings Per Share Amount Operating lease cost Operating Lease Cost Short-term lease cost Short Term Lease Cost Total lease cost Lease Cost Operating Lease Liabilities Payments Due Rolling Maturity [Abstract] 2019 Lessee Operating Lease Liability Payments Remainder Of Fiscal Year 2020 Lessee Operating Lease Liability Payments Due Year Two 2021 Lessee Operating Lease Liability Payments Due Year Three 2022 Lessee Operating Lease Liability Payments Due Year Four 2023 Lessee Operating Lease Liability Payments Due Year Five Thereafter Lessee Operating Lease Liability Payments Due After Year Five Minimum lease payments Lessee Operating Lease Liability Payments Due Imputed interest Lessee Operating Lease Liability Undiscounted Excess Amount Present value of minimum operating lease payments Operating Lease Liability 2019 Operating Leases Future Minimum Payments Due Current 2020 Operating Leases Future Minimum Payments Due In Two Years 2021 Operating Leases Future Minimum Payments Due In Three Years 2022 Operating Leases Future Minimum Payments Due In Four Years 2023 Operating Leases Future Minimum Payments Due In Five Years Thereafter Operating Leases Future Minimum Payments Due Thereafter Total minimum operating lease payments Operating Leases Future Minimum Payments Due Lease Cost [Abstract] Weighted average remaining lease term Operating Lease Weighted Average Remaining Lease Term1 Weighted average discount rate Operating Lease Weighted Average Discount Rate Percent Operating cash flows from operating leases Operating Lease Payments Operating lease liabilities arising from obtaining new operating lease assets Right Of Use Asset Obtained In Exchange For Operating Lease Liability Accrued contract reserves liabilities current. Insurance Accrued Insurance Current Payroll and employee benefits Employee Related Liabilities Current Contract reserves Accrued Contract Reserves Liabilities Current Interest Interest Payable Current Income and other taxes Taxes Payable Current Fuel hedge contracts Hedging Liabilities Current Other Other Accrued Liabilities Current Total accrued expenses Line of credit facility optional increase capacity. Debt Instrument [Table] Debt Instrument [Table] Credit Facility Credit Facility [Axis] Credit Facility Credit Facility [Domain] Revolving Credit Facility [Member] Revolving Credit Facility [Member] Range Range [Axis] Range Range [Member] Minimum [Member] Minimum [Member] Maximum [Member] Maximum [Member] Variable Rate Variable Rate [Axis] Variable Rate Variable Rate [Domain] Domestic rate. Domestic Rate [Member] Domestic Rate [Member] Daily LIBOR Rate. Daily LIBOR Rate [Member] Daily L I B O R Rate [Member] LIBOR Rate [Member] London Interbank Offered Rate L I B O R [Member] Debt Instrument Debt Instrument [Axis] Debt Instrument, Name Debt Instrument Name [Domain] Eight percent senior notes due in two thousand twenty two. 8.000% Senior Notes Due in 2022 [Member] Eight Percent Senior Notes Due In Two Thousand Twenty Two [Member] Debt Instrument [Line Items] Debt Instrument [Line Items] Line of credit facility, maximum borrowing capacity Line Of Credit Facility Maximum Borrowing Capacity Line of credit facility optional increase capacity Line Of Credit Facility Optional Increase Capacity Number of days prior to scheduled maturity date. Fixed charge coverage ratio. Fixed charge coverage ratio Fixed Charge Coverage Ratio Revolving credit facility, maturity date Line Of Credit Facility Expiration Date1 Description of refinanced notes maturity after the maturity date Debt Instrument Maturity Date Description Number of days prior to scheduled maturity date Number Of Days Prior To Scheduled Maturity Date Interest margin applicable rate. Debt instrument, basis spread on variable rate Debt Instrument Basis Spread On Variable Rate1 Interest margin applicable Interest Margin Applicable Rate Letters of credit outstanding Letters Of Credit Outstanding Amount Letter of credit remaining borrowing capacity Line Of Credit Facility Remaining Borrowing Capacity Availability under credit agreement suppressed Line Of Credit Facility Current Borrowing Capacity Debt instrument, face amount Debt Instrument Face Amount Debt instrument, interest rate, stated percentage Debt Instrument Interest Rate Stated Percentage Maturity date Debt Instrument Maturity Date Owned domestic subsidiaries percent. Owned Domestic Subsidiaries Percent Owned Domestic Subsidiaries Percent Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table] Hedging Relationship Derivative Instruments Gain Loss By Hedging Relationship [Axis] Hedging Relationship Hedging Relationship [Domain] Fuel hedge contracts. Fuel Hedge Contracts [Member] Fuel Hedge Contracts [Member] Fair Value Hierarchy and NAV Fair Value By Fair Value Hierarchy Level [Axis] Fair Value Hierarchy and NAV Fair Value Measurements Fair Value Hierarchy [Domain] Fair Value, Inputs, Level 1 [Member] Fair Value Inputs Level1 [Member] Significant Other Observable Inputs (Level 2) [Member] Fair Value Inputs Level2 [Member] Significant Unobservable Inputs (Level 3) [Member] Fair Value Inputs Level3 [Member] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Line Items] Fair Value, Net Asset (Liability) Fair Value Net Asset Liability Derivative underlying hedge percent. Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Fair Values Derivatives Balance Sheet Location By Derivative Contract Type By Hedging Designation [Table] Derivatives Fair Value [Line Items] Derivatives Fair Value [Line Items] Derivative underlying hedge percent Derivative Underlying Hedge Percent Derivative, Nonmonetary Notional Amount, Volume Derivative Nonmonetary Notional Amount Volume Fixed price range Derivative Swap Type Fixed Price Fair value hedge liabilities Fair Value Hedge Liabilities At Fair Value Reclassification of derivative gains (losses) to earnings—net of tax Other Comprehensive Income Loss Reclassification Adjustment From A O C I On Derivatives Net Of Tax Balance Sheet Location Balance Sheet Location [Axis] Balance Sheet Location Balance Sheet Location [Domain] Accrued Expenses [Member] Accounts Payable And Accrued Liabilities [Member] Hedging Designation Hedging Designation [Axis] Hedging Designation Hedging Designation [Domain] Derivatives Designated as Hedging Instruments [Member] Designated As Hedging Instrument [Member] Liability derivatives Cumulative translation adjustments—net of tax Reclassification of derivative (gains) losses to earnings—net of tax Change in fair value of derivatives—net of tax Other Comprehensive Income Unrealized Gain Loss On Derivatives Arising During Period Net Of Tax Net change in cash flow derivative hedges—net of tax Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Derivative Instruments Gain Loss By Hedging Relationship By Income Statement Location By Derivative Instrument Risk [Table] Accumulated Gain Loss Net Cash Flow Hedge Parent [Member] Accumulated Gain Loss Net Cash Flow Hedge Parent [Member] Reclassification out of Accumulated Other Comprehensive Income Reclassification Out Of Accumulated Other Comprehensive Income [Axis] Reclassification out of Accumulated Other Comprehensive Income Reclassification Out Of Accumulated Other Comprehensive Income [Domain] Reclassification Out of Accumulated Other Comprehensive Income [Member] Reclassification Out Of Accumulated Other Comprehensive Income [Member] Accumulated Foreign Currency Adjustment Attributable to Parent [Member] Accumulated Translation Adjustment [Member] Derivative Instruments Gain Loss [Line Items] Derivative Instruments Gain Loss [Line Items] Other expense Costs of contract revenues Income tax (provision) benefit Net income (loss) Stated interest rate Fair value of debt Debt Instrument Fair Value Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Title of Individual Title Of Individual [Axis] Relationship to Entity Title Of Individual With Relationship To Entity [Domain] Employees and directors. Employees and Directors [Member] Employees And Directors [Member] Plan Name Plan Name [Axis] Plan Name Plan Name [Domain] Two thousand seventeen long-term incentive plan. 2017 Long-Term Incentive Plan [Member] Two Thousand Seventeen Long Term Incentive Plan [Member] Two thousand seven long-term incentive plan. 2007 Long-Term Incentive Plan [Member] Two Thousand Seven Long Term Incentive Plan [Member] Share-based Compensation Arrangement by Share-based Payment Award [Line Items] Share Based Compensation Arrangement By Share Based Payment Award [Line Items] Share-based compensation arrangement by share-based payment award, number of shares available for grant Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant Underlying equity awards issued Share Based Compensation Arrangement By Share Based Payment Award Shares Issued In Period Restricted stock units Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Percentage of performance obligation to be recognized as revenue. Performance obligation expected to be recognized as revenue, year. Revenue from contract with customer line items. Revenue from contract with customer table. Revenue From Contract With Customer [Table] Revenue From Contract With Customer [Table] Other current and noncurrent assets. Other Current and Noncurrent Assets [Member] Other Current And Noncurrent Assets [Member] Revenue From Contract With Customer [Line Items] Revenue From Contract With Customer [Line Items] Revenue, remaining performance obligation Revenue Remaining Performance Obligation Percentage of performance obligation to be recognized as revenue Percentage Of Performance Obligation To Be Recognized As Revenue Performance obligation, expected to be recognized as revenue year Performance Obligation Expected To Be Recognized As Revenue Year Remaining performance obligation, expected timing of satisfaction, year Revenue Remaining Performance Obligation Expected Timing Of Satisfaction Year1 Disaggregation Of Revenue [Abstract] Disaggregation Of Revenue [Table] Disaggregation Of Revenue [Table] Subsegments Subsegments [Axis] Subsegments Subsegments [Domain] Type of work. Type of Work [Member] Type Of Work [Member] Consolidation Items Consolidation Items [Axis] Consolidation Items Consolidation Items [Domain] Operating Segment [Member] Operating Segments [Member] Segments Statement Business Segments [Axis] Segments Segment [Domain] Dredging. Dredging [Member] Dredging [Member] Product and Service Product Or Service [Axis] Product and Service Products And Services [Domain] Capital dredging - U.S. Capital-U.S. [Member] Capital Dredging U S [Member] Capital dredging - Foreign. Capital-Foreign [Member] Capital Dredging Foreign [Member] Beach nourishment dredging. Coastal Protection [Member] Beach Nourishment Dredging [Member] Maintenance dredging. Maintenance [Member] Maintenance Dredging [Member] Rivers & Lakes. Rivers & Lakes [Member] Rivers Lakes [Member] Disaggregation Of Revenue [Line Items] Disaggregation Of Revenue [Line Items] Revenues Type of customer. Type of Customer [Member] Type Of Customer [Member] Geographical Statement Geographical [Axis] Geographical Segment Geographical [Domain] Federal government. Federal Government [Member] Federal Government [Member] State and local government. State and Local Government [Member] State And Local Government [Member] Private. Private [Member] Private [Member] Foreign. Foreign [Member] Foreign [Member] Accounts receivable billed for long term completed contracts or programs. Accounts receivable billed for long term contracts or programs in progress. Receivables [Abstract] Completed contracts Accounts Receivable Billed For Long Term Completed Contracts Or Programs Contracts in progress Accounts Receivable Billed For Long Term Contracts Or Programs In Progress Retainage Contract Receivable Retainage Accounts receivable, gross Accounts Receivable Gross Allowance for doubtful accounts Allowance For Doubtful Accounts Receivable Total accounts receivable—net Accounts Receivable Net Costs and earnings for contracts in progress. Billings for contracts in progress. Schedule Of Accounts Notes Loans And Financing Receivable [Table] Schedule Of Accounts Notes Loans And Financing Receivable [Table] Receivable Type Accounts Notes Loans And Financing Receivable By Receivable Type [Axis] Receivable Receivable Type [Domain] Costs and earnings in excess of billings. Costs And Earnings In Excess Of Billings [Member] Costs And Earnings In Excess Of Billings [Member] Billings in excess of costs and earnings. Billings In Excess Of Costs And Earnings [Member] Billings In Excess Of Costs And Earnings [Member] Accounts Notes And Loans Receivable [Line Items] Accounts Notes And Loans Receivable [Line Items] Costs and earnings for contracts in progress Costs And Earnings For Contracts In Progress Amounts billed Billings For Contracts In Progress Costs and earnings in excess of billings for contracts in progress Costs And Earnings In Excess Of Billings For Contracts In Progress Costs and earnings in excess of billings for completed contracts Costs And Earnings In Excess Of Billings For Completed Contracts Total contract revenues in excess of billings Accounts Receivable Billed For Long Term Contracts Or Programs Long-term contract revenues in excess of billings Contract Receivable Due After One Year Total billings in excess of contract revenues Costs to fulfill a contract with customer recognized as an asset Capitalized Contract Cost Gross Amortization on pre-construction costs Capitalized Contract Cost Amortization Schedule Of Restructuring And Related Costs [Table] Schedule Of Restructuring And Related Costs [Table] Restructuring Type Restructuring Cost And Reserve [Axis] Type of Restructuring Type Of Restructuring [Domain] Severance [Member] Employee Severance [Member] Asset retirements. Asset Retirements [Member] Asset Retirements [Member] Pre-contract costs. Pre-contract Costs [Member] Precontract Costs [Member] Closeout costs. Closeout Costs [Member] Closeout Costs [Member] Restructuring Cost And Reserve [Line Items] Restructuring Cost And Reserve [Line Items] Estimated restructuring charge Restructuring And Related Cost Expected Cost1 Dredging segment. Dredging [Member] Dredging Segment [Member] Income Statement Location Income Statement Location [Axis] Income Statement Location Income Statement Location [Domain] Costs of contract revenues - depreciation. Costs of Contract Revenues - Depreciation [Member] Costs Of Contract Revenues Depreciation [Member] Costs of contract revenues - other. Costs of Contract Revenues - Other [Member] Costs Of Contract Revenues Other [Member] General and Administrative Expenses [Member] General And Administrative Expense [Member] Loss on sale of assets net. Loss on Sale of Assets - Net [Member] Loss On Sale Of Assets Net [Member] Other Expense [Member] Other Nonoperating Income Expense [Member] Restructuring charges Restructuring Charges Severance expense Severance Costs1 Bids bond range. Outstanding performance bonds. Revenue value remaining from outstanding performance bonds. Commitments and contingencies. Commitments and contingencies. Commitments And Contingencies [Table] Commitments And Contingencies [Table] Environmental and infrastructure segment. Environmental and Infrastructure Segment [Member] Environmental And Infrastructure Segment [Member] Letter of Credit [Member] Letter Of Credit [Member] Loss Contingency Nature Loss Contingencies By Nature Of Contingency [Axis] Loss Contingency, Nature Loss Contingency Nature [Domain] Surety Bond [Member] Surety Bond [Member] Energy Energy [Axis] Energy Energy [Domain] Crude Oil [Member] Crude Oil [Member] Commitments And Contingencies [Line Items] Commitments And Contingencies [Line Items] Bids bond range Bids Bond Range Outstanding performance bonds Outstanding Performance Bonds Revenue value remaining from outstanding performance bonds Revenue Value Remaining From Outstanding Performance Bonds Aggregate demolition surety performance bond Loss Contingency Damages Sought Value Warranty periods. Warranty periods Warranty Periods Proceeds from Legal Settlements Proceeds From Legal Settlements Loss contingency, Estimate of possible loss Loss Contingency Estimate Of Possible Loss Quantity of oil spill. Quantity of oil spill Quantity Of Oil Spill Proceeds from sale of historical environmental and infrastructure business Proceeds From Divestiture Of Businesses Discontinued Operation Income Loss From Discontinued Operation Disclosures [Abstract] Revenue Disposal Group Including Discontinued Operation Revenue Loss before income taxes from discontinued operations Discontinued Operation Income Loss From Discontinued Operation Before Income Tax Loss on disposal of assets held for sale Discontinued Operation Provision For Loss Gain On Disposal Before Income Tax Income tax benefit Discontinued Operation Tax Effect Of Discontinued Operation Loss from discontinued operations, net of income taxes Disposal group including discontinued operation contract revenues in excess of billings current. Disposal group including discontinued operation operating lease assets. Disposal group including discontinued operation provision for loss on disposal noncurrent. Disposal group including discontinued operation operating lease liabilities current. Disposal group including discontinued operation operating lease liabilities noncurrent . Assets: Assets Of Disposal Group Including Discontinued Operation [Abstract] Accounts receivable—net Disposal Group Including Discontinued Operation Accounts Notes And Loans Receivable Net Contract revenues in excess of billings Disposal Group Including Discontinued Operation Contract Revenues In Excess Of Billings Current Other current assets Disposal Group Including Discontinued Operation Other Current Assets Assets held for sale Property and equipment—net Disposal Group Including Discontinued Operation Property Plant And Equipment Noncurrent Operating lease assets Disposal Group Including Discontinued Operation Operating Lease Assets Goodwill Disposal Group Including Discontinued Operation Goodwill Noncurrent Other intangible assets—net Disposal Group Including Discontinued Operation Intangible Assets Noncurrent Other assets Disposal Group Including Discontinued Operation Other Noncurrent Assets Reserve for loss on disposal Disposal Group Including Discontinued Operation Provision For Loss On Disposal Noncurrent Assets held for sale—noncurrent Disposal Group Including Discontinued Operation Assets Noncurrent Liabilities: Liabilities Of Disposal Group Including Discontinued Operation [Abstract] Accounts payable Disposal Group Including Discontinued Operation Accounts Payable Current Accrued expenses Disposal Group Including Discontinued Operation Accrued Liabilities Current Operating lease liabilities Disposal Group Including Discontinued Operation Operating Lease Liabilities Current Other current liabilities Disposal Group Including Discontinued Operation Other Current Liabilities Liabilities held for sale Liabilities Of Disposal Group Including Discontinued Operation Other liabilities Disposal Group Including Discontinued Operation Other Noncurrent Liabilities Operating lease liabilities—noncurrent Disposal Group Including Discontinued Operation Operating Lease Liabilities Noncurrent Liabilities held for sale—noncurrent Liabilities Of Disposal Group Including Discontinued Operation Noncurrent