Accounting Policies [Abstract] Accounting Policies [Abstract] Accounts Payable Current Accounts payable Accounts Receivable Net Current Accounts receivable Accounts Receivable Policy [Text Block] Accounts Receivable Policy [Text Block] Accounts receivable Accrued Liabilities Current Accrued expenses Accumulated Capitalized Interest Costs Interest capitalized Accumulated Vessel Depreciation Accumulated Vessel Depreciation Accumulated Depreciation The cash outflow for acquisition of purchase options for vessels. Acquisition Of Vessel Purchase Options Acquisition of vessel purchase options (note 5) Additional Deferred Financing Costs Additional Deferred Financing Costs Expenditure in the period Fees and related cost paid Additional Paid In Capital Common Stock Additional paid in capital Additional Paid In Capital [Member] Additional Paid in Capital [Member] Adjustments To Additional Paid In Capital Share Based Compensation Restricted Stock Units Requisite Service Period Recognition Restricted Stock Units (note 15) Adjustments To Reconcile Net Income Loss To Cash Provided By Used In Operating Activities [Abstract] Adjustments to Reconcile Net Income (Loss) to Net Cash Provided by Operating Activities After [Member] After [Member] After Merger [Member] Agreed Number of New Buildings Agreed Number Of New Buildings 4,250 TEU new buildings Allocated Share Based Compensation Expense Recognised share based compensation expenses Allowance For Doubtful Accounts Receivable Current Allowances for doubtful accounts Amendment Flag Amendment Flag Amortization [Member] Amortization [Member] Amortization [Member] Amortization Of Deferred Financing Costs Amortization Of Deferred Financing Costs Amortization included within interest expense Amortization Of Financing Costs Amortization of deferred financing costs (note 9) Amortization of Intangible Assets Charter Agreements Amortization Of Intangible Assets Charter Agreements Amortization in period The amount of intangible lease liability amortized as an increase in time charter revenue during the reporting period. Amortization Of Intangible Liabilities Amortization of intangible liability Annual Ship Management Fees Annual Ship Management Fees Annual ship management fees Annual Ship Management Fees Per Vessel Annual Ship Management Fees Per Vessel Annual ship management fee per vessel Anticipated Leverage Ratio Anticipated Leverage Ratio Anticipated Leverage Ratio Range Approximate Remaining Charter Term Approximate Remaining Charter Term Remaining Charter Duration (years) Remaining terms April Eleven Two Thousand Thirteen [Member] April Eleven Two Thousand Thirteen [Member] April 11, 2013 [Member] Asset Impairment Charges Impairment charge (note 5) Impairment of vessel deposits Impairment - vessel purchase options Assets Total Assets Assets [Abstract] Assets Assets Current Total current assets Assets [Member] Assets [Member] Assets Noncurrent Total non-current assets At Merger [Member] At Merger [Member] At Merger [Member] Available To Allocate Prorata Between Classa And Classb Basic Available To Allocate Prorata Between Classa And Classb Basic Available to- allocate pro-rata between Class A and B Available To Allocate Prorata Between Classa And Classb Diluted Available To Allocate Prorata Between Classa And Classb Diluted Available to - allocate pro rata between Class A and B Bonds Redeemable For Shares Bonds Redeemable For Shares Bonds redeemable for shares Business Acquisition Acquiree [Domain] Business Acquisition, Acquiree [Domain] Business Acquisition [Axis] Business Acquisition [Axis] Capacity Of Vessels In Twenty Foot Equivalent Units Capacity Of Vessels In Twenty Foot Equivalent Units Capacity in TEUs The cash outflow for capitalized costs relating to drydocking. Capitalized Costs Relating To Dry Docking Costs relating to drydockings Cash And Cash Equivalents At Carrying Value Cash and Cash Equivalents at end of Year Cash and Cash Equivalents at start of Year Cash and cash equivalents Cash And Cash Equivalents Period Increase Decrease Net Increase(Decrease) in Cash and Cash Equivalents Cash And Cash Equivalents Policy [Text Block] Cash and cash equivalents Cash And Cash Equivalents Restricted Cash And Cash Equivalents Policy Restricted cash Charterhire Amount Outstanding Charterhire Amount Outstanding Charter hire outstanding Charterhire, outstanding amount Charterhire Due Date Charterhire Due Date Charter hire due date Charterhire, due date Charter Hire Future Maximum Contracted Receivable Current Charter Hire Future Maximum Contracted Receivable Current 2013 Charter Hire Future Maximum Contracted Receivable In Five Years Charter Hire Future Maximum Contracted Receivable In Five Years 2017 Charter Hire Future Maximum Contracted Receivable In Four Years Charter Hire Future Maximum Contracted Receivable In Four Years 2016 Charter Hire Future Maximum Contracted Receivable In Three Years Charter Hire Future Maximum Contracted Receivable In Three Years 2015 Charter Hire Future Maximum Contracted Receivable In Two Years Charter Hire Future Maximum Contracted Receivable In Two Years 2014 Charter Hire Future Maximum Contracted Receivable Thereafter Charter Hire Future Maximum Contracted Receivable Thereafter Thereafter Class A Warrants [Member] Class A Warrants [Member] Class A Warrants [Member] Class Of Stock [Domain] Class of Stock [Domain] Class Of Stock [Line Items] Class of Stock [Line Items] Cma Cgma Llcazar [Member] Cma Cgma Llcazar [Member] CMA CGM Alcazar [Member] Cma Cgm America [Member] Cma Cgm America [Member] CMA CGM America [Member] Cma Cgm Berlioz [Member] Cma Cgm Berlioz [Member] CMA CGM Berlioz [Member] Cma Cgm Chteau D lf [Member] Cma Cgm Chteau Lf [Member] CMA CGM Chteau d' lf [Member] Cma Cgm Jamaica [Member] Cma Cgm Jamaica [Member] CMA CGM Jamaica [Member] Cma Cgm La Tour [Member] Cma Cgm La Tour [Member] CMA CGM La Tour [Member] Cma Cgm Manet [Member] Cma Cgm Manet [Member] CMA CGM Manet [Member] Cma Cgm Matisse [Member] Cma Cgm Matisse [Member] CMA CGM Matisse [Member] Cma Cgm [Member] Cma Cgm [Member] CMA CGM [Member] Cma Cgm Sambhar [Member] Cma Cgm Sambhar [Member] CMA CGM Sambhar [Member] Cma Cgm Thalassa [Member] Cma Cgm Thalassa [Member] CMA CGM Thalassa [Member] Cma Cgm Utrillo [Member] Cma Cgm Utrillo [Member] CMA CGM Utrillo [Member] Commitments And Contingencies Commitments and contingencies (note 12) Commitments And Contingencies Disclosure [Abstract] Commitments and Contingencies Disclosure [Abstract] Commitments And Contingencies Disclosure [Text Block] Commitments and Contingencies Common Class A [Member] Class A Common Stock [Member] Common Class B [Member] Class B Common stock [Member] Common Stock Conversion Features Possible future conversion basis for Class B common shares to Class A common shares Common Stock Dividend Per Share Declared Common Stock Dividend Per Share Declared Dividends declared Common Stock [Member] Common Stock [Member] Common Stock Par Or Stated Value Per Share Common stock, par value Common Stock Shares Authorized Common stock, shares authorized Common Stock Shares Issued Common stock, shares issued Common Stock Shares Outstanding Balance, shares Balance, shares Common stock, shares outstanding Common Stock Value Common stock Component Of Other Expense Nonoperating [Axis] Component of Other Expense, Nonoperating [Axis] Component Of Other Expense Nonoperating Name [Domain] Component of Other Expense, Nonoperating, Name [Domain] Component Of Other Operating Cost And Expense General [Axis] Component of Other Operating Cost and Expense [Axis] Component Of Other Operating Cost And Expense Name [Domain] Component of Other Operating Cost and Expense, Name [Domain] Component Of Other Operating Income [Line Items] Component Of Other Operating Income [Line Items] Component Of Other Operating Income [Line Items] Component Of Other Operating Income [Table] Component Of Other Operating Income [Table] Component Of Other Operating Income [Table] Concentration Risk Disclosure [Text Block] Risks Associated with Concentration Concentration Risk [Line Items] Concentration Risk [Line Items] Concentration Risk [Table] Concentration Risk [Table] Consolidation Policy [Text Block] Basis of consolidation Corporate Income Tax Rate Corporate Income Tax Rate Principal rate of corporate income tax Costs And Expenses Total operating expenses Costs And Expenses [Abstract] Operating Expenses Costs Reimbursed Per Day Costs Reimbursed Per Day Cost reimbursement per vessel per day Creation Date [Axis] Report Date [Axis] Credit Facility [Axis] Credit Facility [Axis] Credit Facility [Domain] Credit Facility [Domain] Credit Facility [Member] Credit Facility [Member] Credit Facility [Member] Current Fiscal Year End Date Current Fiscal Year End Date Daily Charter Rate Daily Charter Rate Daily Charter Rate Debt Disclosure [Abstract] Debt Disclosure [Abstract] Debt Instrument Basis Spread On Variable Rate Credit Facility Margin Debt Instrument Covenant Description Financial covenants of credit facility Debt Instrument [Line Items] Debt Instrument [Line Items] Debt Instrument [Table] Schedule of Long-term Debt Instruments [Table] Default Financial Statements Date [Member] Financial Statements Date [Domain] Deferred Compensation Arrangement With Individual Excluding Share Based Payments And Postretirement Benefits By Title Of Individual [Axis] Deferred Bonus and Profit Sharing Plan by Title of Individual [Axis] Deferred Costs Capitalized Prepaid And Other Assets Disclosure [Abstract] Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Abstract] Deferred Costs Current And Noncurrent [Line Items] Deferred Costs Current And Noncurrent [Line Items] Deferred Costs Current And Noncurrent [Line Items] Deferred Finance Costs Current Net Deferred financing costs (note 7) Deferred Finance Costs Net Closing balance Opening balance Deferred Finance Costs Noncurrent Net Deferred financing costs (note 7) Deferred Financing Costs [Line Items] Deferred Financing Costs [Line Items] Deferred Financing Costs [Line Items] Deferred Financing Costs Policy [Text Block] Deferred Financing Costs Policy [Text Block] Deferred financing costs Deferred Financing Costs [Text Block]. Deferred Financing Costs [Text Block] Deferred Financing Costs Deferred Financing Cost [Table] Deferred Financing Cost [Table] Deferred Financing Cost [Table] Deferred Tax Assets Net Deferred tax asset Deferred Tax Assets Net Current Deferred tax Deferred Tax Assets Net Noncurrent Deferred tax Deferred Tax Liabilities Deferred tax liability recognized Deferred Tax Liabilities Noncurrent Deferred tax liability Delmas Keta [Member] Delmas Keta [Member] Delmas Keta [Member] Depreciation And Amortization Of Capitalized Software Depreciation And Amortization Of Capitalized Software Depreciation - software development Depreciation Depletion And Amortization Depreciation Derivative Fixed Interest Rate Fixed Rate % Derivative Inception Dates Start Date Derivative Instrument Eight [Member] Derivative Instrument Eight [Member] December 17, 2008, Five [Member] Derivative Instrument Five [Member] Derivative Instrument Five [Member] December 17, 2008, Two [Member] Derivative Instrument Four [Member] Derivative Instrument Four [Member] December 17, 2008, One [Member] Derivative Instrument Nine [Member] Derivative Instrument Nine [Member] July 15, 2009 [Member] Derivative Instrument One [Member] Derivative Instrument One [Member] May 19, 2008 [Member] Derivative Instruments And Hedging Activities Disclosure [Abstract] Derivative Instruments and Hedging Activities Disclosure [Abstract] Derivative Instruments And Hedging Activities [Line Items] Derivative Instruments And Hedging Activities [Line Items] Derivative Instruments And Hedging Activities [Line Items] Disclosure of the entity's derivative instruments. Derivative Instruments Disclosure [Text Block] Derivative Instruments Derivative Instrument Seven[Member] Derivative Instrument Seven [Member] December 17, 2008, Four [Member] 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] Derivative Instruments Gain Loss [Line Items] Derivative Instruments, Gain (Loss) [Line Items] Derivative Instrument Six [Member] Derivative Instrument Six [Member] December 17, 2008, Three [Member] Derivative Instruments [Line Items] Derivative Instruments [Line Items] Derivative Instruments [Line Items] Derivative Instruments [Member] Derivative Instruments [Member] May 12, 2008 [Member] Derivative Instruments [Table] Derivative Instruments [Table] Derivative Instruments [Table] Derivative Instrument Ten [Member] Derivative Instrument Ten [Member] October 29, 2010 [Member] Derivative Instrument Three [Member] Derivative Instrument Three [Member] November 19, 2008 [Member] Derivative Instrument Two [Member] Derivative Instrument Two [Member] May 20, 2008 [Member] Derivative Liabilities Current Derivative instruments (note 6) Derivative Liabilities Noncurrent Derivative instruments (note 6) Derivative Maturity Dates Maturity Date Derivative Notional Amount Nominal Value of Interest Rate Swap Agreements Notional Amount Derivatives Policy [Text Block] Derivative instruments Director [Member] Director [Member] Disclosure Of Compensation Related Costs Sharebased Payments [Abstract] Disclosure of Compensation Related Costs, Share-based Payments [Abstract] Disclosure Of Compensation Related Costs Share Based Payments [Text Block] Share-Based Compensation Dividends Policy [Text Block] Dividends Policy [Text Block] Dividends Document Document and Entity Information [Abstract] Document Document And Entity Information [Abstract] Document Documentand Entity Information [Abstract] Document Fiscal Period Focus Document Fiscal Period Focus Document Fiscal Year Focus Document Fiscal Year Focus Document Information [Table] Document Information [Table] Document Period End Date Document Period End Date Document Type Document Type Drydock Expenditure in Progress Drydock Expenditure In Progress Drydock expenditure - in progress Drydocking Cost [Policy Text Block] Drydocking Cost Policy [Text Block] Drydocking costs Due From Related Parties Current Amounts due from CMA CGM companies presented within assets Due To Related Parties Current Amounts due to CMA CGM companies presented within liabilities Earnings Per Share [Abstract] Net Income (Loss) in $ per share Earnings Per Share Basic Basic (note 17) Earnings per share Earnings Per Share Basic [Abstract] Basic Earnings per Share Earnings Per Share Basic And Diluted [Line Items] Earnings Per Share Basic And Diluted [Line Items] Earnings Per Share Basic And Diluted [Line Items] Earnings Per Share Diluted Diluted (note 17) Earnings per share Earnings Per Share Diluted [Abstract] Diluted Earnings per Share Earnings Per Share Policy [Text Block] Earnings per share Earnings Per Share ProForma [Table] Earnings Per Share Pro Forma [Table] Earnings Per Share ProForma [Table] Earnings Per Share [Text Block] Earnings per Share Period remaining over which the unrecognized costs will be recognized for equity-based compensation plans. Employee Service Share Based Compensation Nonvested Awards Compensation Cost Not Yet Recognized Expected Period For Recognition Remaining expected recognized cost period Employee Service Share Based Compensation Nonvested Awards Total Compensation Cost Not Yet Recognized Unrecognised compensation cost Entity Central Index Key Entity Central Index Key Entity Common Stock Shares Outstanding Entity Common Stock, Shares Outstanding Entity Current Reporting Status Entity Current Reporting Status Entity [Domain] Entity [Domain] Entity Filer Category Entity Filer Category Entity Information [Line Items] Entity Information [Line Items] Entity Registrant Name Entity Registrant Name Entity Voluntary Filers Entity Voluntary Filers Entity Well Known Seasoned Issuer Entity Well-known Seasoned Issuer Entity Wide Revenue Major Customer Percentage Percentage of revenue Equity [Abstract] Equity [Abstract] Equity Component [Domain] Equity Component [Domain] Estimated Repayments of Long-term Debt Estimated Repayments Of Longterm Debt Estimated repayments of long term debt Expenditure in the reporting period on vessel purchases, vessel deposits and other capitalisable amounts. Expenditure On Vessels Vessel Prepayments And Vessel Deposits Cash paid for purchase of vessels, vessel prepayments and vessel deposits Fair Value And Derivative Instruments [Table] Fair Value And Derivative Instruments [Table] Fair Value And Derivative Instruments [Table] Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain] Fair Value by Asset Class [Domain] Fair Value By Asset Class [Axis] Asset Class [Axis] Fair Value By Liability Class [Axis] Liability Class [Axis] Fair Value Interest Rate Swap Hedging Instruments Fair Value Interest Rate Swap Fair value of interest rate swap hedging instruments -current and non current portions Interest rate swap agreements, liability Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation By Liability Class [Domain] Fair Value by Liability Class [Domain] Fair Value Of Purchase Option Fair Value Of Purchase Option Fair value of purchase options Financial Instrument [Axis] Financial Instrument [Axis] Finite Lived Intangible Assets [Line Items] Finite-Lived Intangible Assets [Line Items] Foreign Currency Transaction Gain Loss Unrealized Unrealized foreign exchange loss (gain) Foreign Currency Transactions And Translations Policy [Text Block] Foreign currency transactions French Fonds Strategique Investissement [Member] French Fonds Strategique Investissement [Member] French Fonds Strategique d'Investissement [Member] G B UNITED KINGDOM General And Administrative Expense General and administrative General [Text Block]. General [Text Block] General Goodwill And Intangible Assets Disclosure [Abstract] Goodwill and Intangible Assets Disclosure [Abstract] Goodwill And Intangible Assets Policy [Text Block] Intangible assets Granted In March [Member] Granted In March [Member] Granted in March [Member] Granted In September [Member] Granted In September [Member] Granted In September [Member] Income Loss From Continuing Operations Before Income Taxes Minority Interest And Income Loss From Equity Method Investments Income (Loss) before Income Taxes Income Statement [Abstract] Income Statement [Abstract] Income Taxes Paid Total income tax paid Income Tax Expense Benefit Income taxes Income Tax Policy [Text Block] Income taxes Increase Decrease In Accounts Payable And Other Operating Liabilities Increase (decrease) in accounts payable and other liabilities Increase Decrease In Fair Value Of Unhedged Derivative Instruments Change in fair value of certain derivative instruments (note 14) The (increase) decrease during the reporting period in the total amount of receivables from all parties and other assets not separately disclosed in the statement of cash flows. Increase Decrease In Receivables And Other Assets (Increase) decrease in receivables and other assets Increase Decrease In Restricted Cash Variation in restricted cash (note 13) Incremental Common Shares Attributable To Share Based Payment Arrangements Dilutive effect of share-based awards Insurance Policy [Text Block] Insurance Policy [Text Block] Insurance Intangible Assets Disclosure [Text Block] Intangible Assets Intangible Assets [Line Items] Intangible Assets [Line Items] Intangible Assets [Line Items] Intangible Assets Net Excluding Goodwill Closing balance Opening balance - vessel purchase options and software development Intangible Assets [Table] Intangible Assets [Table] Intangible Assets [Table] Intangible Liabilities Charter Agreements [Policy Text Block] Intangible Liabilities Charter Agreements Policy [Text Block] Intangible liabilities - charter agreements Intangible Liability Charter Agreements, Net Of Accumulated Amortization Intangible Liability Charter Agreements Closing balance Opening balance Current portion of the excess of the market value of vessel charters over contracted value of the charters at the date of merger. The intangible lease liability is amortized as an increase in time charter revenue over the remaining term of the relevant charter. Intangible Liability Charter Agreements Current Intangible liability - charter agreements (note 8) Non current portion of the excess of the market value of vessel charters over contracted value of the charters at the date of merger. The intangible lease liability is amortized as an increase in time charter revenue over the remaining term of the relevant charter. Intangible Liability Charter Agreements Noncurrent Intangible liability - charter agreements (note 8) Disclosure on Intangible Liabilities relating to Charter Agreements. Intangible Liability Charter Agreements [Text Block] Intangible Liability - Charter Agreements Interest Expense Interest expense The amount of cash paid for interest on debt and for dividends of preferred shares during the period. Interest Paid In Period Total interest paid The disclosure for derivatives and their fair value. Interest Rate Derivatives And Fair Value [Text Block] Interest Rate Derivatives and Fair Value Measurements Investment Income Interest Interest income Julie Delmas [Member] Julie Delmas [Member] Julie Delmas [Member] Kumasi [Member] Kumasi [Member] Kumasi [Member] Legal Entity [Axis] Legal Entity [Axis] Maximum Permitted Leverage Ratio. Leverage Ratio Maximum Maximum Leverage Ratio Maximum Leverage Ratio under credit facility Liabilities Total Liabilities Liabilities And Stockholders Equity Total Liabilities and Stockholders' Equity Liabilities And Stockholders Equity [Abstract] Liabilities and Stockholders' Equity Liabilities Current Total current liabilities Liabilities Noncurrent Total long-term liabilities Liability [Member] Liability [Member] Line Of Credit Facility Expiration Date 1 Maturity date of credit facility Line Of Credit Facility Frequency Of Payments Prepayment of borrowings Line Of Credit Facility Interest Rate Description Interest rate on Credit facility Line Of Credit Facility [Line Items] Line of Credit Facility [Line Items] Line Of Credit Facility Maximum Borrowing Capacity Senior secured credit facility Line Of Credit Facility Periodic Payment Principal Credit facility actual repayment Line Of Credit Facility [Table] Line of Credit Facility [Table] Long Lived Assets Policy [Text Block] Long Lived Assets Policy [Text Block] Long-lived assets Long term debt classification. Long Term Debt Classification Policy [Text Block] Classification of long term debt Long Term Debt Current Current portion of long-term debt (note 9) Less current instalments of long-term debt Long Term Debt Current And Non Current Long Term Debt Current And Non Current Credit facility, at Libor USD + 2.50% to 3.75% Long-term Debt, Estimated, Repayments of Principal in Next Twelve Months Longterm Debt Estimated Repayments Of Principal In Next Twelve Months 2013 Long-term Debt, Estimated, Repayments of Principal in Year Four Longterm Debt Estimated Repayments Of Principal In Year Four 2016 Long-term Debt, Estimated, Repayments of Principal in Year Three Longterm Debt Estimated Repayments Of Principal In Year Three 2015 Long-term Debt, Estimated, Repayments of Principal in Year Two Longterm Debt Estimated Repayments Of Principal In Year Two 2014 Long Term Debt Estimated Repayments Of Principal [Line Items] Long Term Debt Estimated Repayments Of Principal [Line Items] Long Term Debt Estimated Repayments Of Principal [Line Items] Long Term Debt Maturities Estimated Repayments Of Principal [Table] Long Term Debt Maturities Estimated Repayments Of Principal [Table] Long Term Debt Maturities Estimated Repayments Of Principal [Table] Long Term Debt Noncurrent Long term debt Long-term debt (note 9) Long Term Debt [Text Block] Long Term Debt Term of the incentive plan. Long Term Incentive Plan Term Term of Equity Incentive Plan Management [Member] Management [Member] Management Member One [Member] Management Member One [Member] Three members of management [Member] Management Member Two [Member] Management Member Two [Member] One member of management [Member] Marie Delmas [Member] Marie Delmas [Member] Marie Delmas [Member] Maximum Contracted Charter Hire Receivable Maximum Contracted Charter Hire Receivable Maximum contracted charter hire receivable Total Operating leases Maximum Length Of Time Interest Rate Hedged Maximum Length Of Time Interest Rate Hedged Maximum length of time over which Company has hedged its interest rate exposure Maximum [Member] Maximum [Member] Maximum shares to any participant per year. Maximum Shares To Any Participant Per Year Maximum number of shares which may be granted to any participant in any fiscal year Merger cash flow projections discount rate. Merger Cash Flow Projections Discount Rate Discount rate of projected lease cash flow Minimum [Member] Minimum [Member] Minimum Preferred Shares Redemption Installment Minimum Preferred Shares Redemption Installment Minimum redemption installment Nature Of Operations And Basis Of Preparation [Line Items] Nature Of Operations And Basis Of Preparation [Line Items] Nature Of Operations And Basis Of Preparation [Line Items] Nature Of Operations And Basis Of Preparation [Table] Nature Of Operations And Basis Of Preparation [Table] Nature Of Operations And Basis Of Preparation [Table] Nature Of Operations [Line Items] Nature Of Operations [Line Items] Nature Of Operations [Line Items] Nature Of Operations [Table] Nature Of Operations [Table] Nature Of Operations [Table] Net Cash Provided By Used In Financing Activities Net Cash Used in Financing Activities Net Cash Provided By Used In Financing Activities [Abstract] Cash Flows from Financing Activities Net Cash Provided By Used In Investing Activities Net Cash Used in Investing Activities Net Cash Provided By Used In Investing Activities [Abstract] Cash Flows from Investing Activities Net Cash Provided By Used In Operating Activities Net Cash Provided by Operating Activities Net Cash Provided By Used In Operating Activities [Abstract] Cash Flows from Operating Activities Net Income Available To Classa Share Holders For Arrears Net Income Available To Classa Share Holders For Arrears Available to - Class A shareholders for arrears Net Income Loss Net Income (Loss) Net Income (Loss) Net income (loss) for the year Net Income Loss Available To Common Stockholders Basic Net income (loss) available to shareholders Net income (loss) available to shareholders Net Income Loss Available To Common Stockholders Diluted Net income (loss) available to shareholders Net income (loss) available to shareholders Nonoperating Income Expense [Abstract] Non Operating Income (Expense) Number of banks holding deposits of cash and cash equivalents Number Of Banks Holding Deposits Number of banks in which cash and cash equivalents deposited Number of Preferred Shares Installments Number Of Preferred Shares Installments Redeemable preference shares, quarterly installments Number Of Vessels Number Of Vessels Number of vessels Number of vessels delivered Number Of Vessels Chartered Number Of Vessels Chartered Number of vessels Number Of Vessels Pledged As Collateral Under Credit Facility Number Of Vessels Pledged As Collateral Under Credit Facility Number of vessels pledged as collateral under credit facility agreement Number Of Vessels Tested For Potential Impairment Number Of Vessels Tested For Potential Impairment Number of vessels tested for potential impairment Operating Income Loss Operating Income Organization Consolidation And Presentation Of Financial Statements [Abstract] Organization, Consolidation and Presentation of Financial Statements [Abstract] Organization Consolidation And Presentation Of Financial Statements Disclosure [Text Block] Nature of Operations and Basis of Preparation Aggregate carrying amount, as of the balance sheet date, of noncurrent assets not separately disclosed in the balance sheet net of accumulated amortization and any impairment. Noncurrent assets are expected to be realized or consumed after one year (or the normal operating cycle, if longer). Other Assets Noncurrent Net Other fixed assets Other Comprehensive Income Loss Policy [Text Block] Other Comprehensive Income Loss Policy [Text Block] Other comprehensive income (loss) The gross carrying amount of other intangible assets such as software development, net of accumulated amortization and any impairment. Other Finite Lived Intangible Assets Net Intangible assets - other (note 5) Other Income And Expenses [Abstract] Other Income and Expenses [Abstract] Other Income And Other Expense Disclosure [Text Block] Other Operating (Income) Expense Other Income [Member] Other sundry income [Member] Other Operating Income Other operating income (note 10) Other operating income Other Receivables Net Current Other receivables Payment Of Preferred Shares Dividends Payment Of Preferred Shares Dividends Preferred Shares Dividend Payments Of Debt Issuance Costs Issuance costs of debt Payments To Acquire Intangible Assets Cash paid for intangible assets Payments To Acquire Other Property Plant And Equipment Cash paid for other fixed assets Period One [Member] Period One [Member] Period One [Member] Period Two [Member] Period Two [Member] Period Two [Member] Preferred Shares Policy [Text Block] Preferred Shares Policy [Text Block] Preferred shares Number of Preferred Shares Redeemed Preferred Shares Redemption Number Number of shares redeemed Preferred Stock Redemption Amount Redemption amount Preferred Stock Redemption Price Per Share Redemption price per share Sum of the amounts paid in advance for costs that will be expensed with the passage of time or the occurrence of a triggering event, and will be charged against earnings within one year or one operating cycle if longer. Prepaid Expenses Current Prepaid expenses Proceeds From Exercise Of Options And Warrants Proceeds From Exercise Of Options And Warrants Total proceeds from exercise of public warrants Property Plant And Equipment [Abstract] Property, Plant and Equipment [Abstract] Property Plant And Equipment By Type [Axis] Property, Plant and Equipment, Type [Axis] Property Plant And Equipment [Line Items] Property, Plant and Equipment [Line Items] Property Plant And Equipment Type [Domain] Property, Plant and Equipment, Type [Domain] Public Warrants [Member] Public Warrants [Member] Public Warrants [Member] Purchase Date Purchase Date Purchase Date by GSL Range [Axis] Range [Axis] Range [Member] Range [Domain] Realized loss on interest rate derivatives. Realized Loss On Interest Rate Derivatives Realized loss on interest rate derivatives Recently Issued Accounting Standards Policy [Text Block] Recently Issued Accounting Standards Policy [Text Block] Recently issued accounting standards Redeemable Preferred Shares Dividend Paid Redeemable Preferred Shares Dividend Paid Redeemable preferred shares dividend paid Aggregate stated value of issued preferred shares redeemable according to a redemption schedule. Redeemable Preferred Shares Value Issued Preferred shares (note 13) Redemption Of Preferred Shares. Redemption Of Preferred Shares Repayment of preferred shares (note 13) Related Party [Domain] Related Party [Domain] Related Party Transaction [Line Items] Related Party Transaction [Line Items] Related Party Transactions [Abstract] Related Party Transactions [Abstract] Related Party Transactions By Related Party [Axis] Related Party [Axis] Related Party Transactions Disclosure [Text Block] Related Party Transactions Repairs And Maintenance Policy [Text Block] Repairs And Maintenance Policy [Text Block] Repairs and maintenance Repayments Of Debt Repayments of debt Required Class A common shares dividend per quarter. Required Classa Common Shares Dividend Per Quarter Required Class A common shares dividend per quarter The carrying amounts of cash and cash equivalent items which are restricted as to withdrawal or usage. Restricted Cash And Cash Equivalent Restricted cash (note 13) Restricted stock share based compensation vesting period. Restricted Stock Share Based Compensation Vesting Period Restricted stock share based compensation vesting period Restricted stock units share based compensation awards granted Restricted Stock Units Share Based Compensation Awards Granted Granted, Number of Units Restricted stock units share based compensation awards number vested. Restricted Stock Units Share Based Compensation Awards Number Vested Restricted stock units share based compensation awards number vested Restricted Stock Units Share Based Compensation Awards Share Value On Vesting Date Restricted Stock Units Share Based Compensation Awards Share Value On Vesting Date Actual Fair Value on Vesting date Restricted Stock Units Share Based Compensation Awards Vested In Period Restricted Stock Units Share Based Compensation Awards Vested In Period Vested, Number of Units Retained Earnings Accumulated Deficit Retained earnings (accumulated deficit) Retained Earnings (Accumulated Deficit) [Member] Retained Earnings Accumulated Deficit [Member] Accumulated Deficit [Member] Revenue Recognition and Related Operating Expenses [Policy Text Block] Revenue Recognition Related Operating Expenses Policy [Text Block] Revenue recognition and related operating expense Revenues [Abstract] Operating Revenues Risks And Uncertainties [Abstract] Risks and Uncertainties [Abstract] Schedule Of Commitments And Contingencies [Line Items] Schedule Of Commitments And Contingencies [Line Items] Schedule Of Commitments And Contingencies [Line Items] Schedule Of Commitments And Contingencies [Table] Schedule Of Commitments And Contingencies [Table] Schedule Of Commitments And Contingencies [Table] Schedule Of Commitments And Contingencies Table [Text Block] Schedule Of Commitments And Contingencies Table [Text Block] Maximum Contracted Future Annual Charter Hire Receivable Before Allowance for Any Off-Hire periods Schedule Of Deferred Financing Costs [Table Text Block] Schedule Of Deferred Financing Costs Table [Text Block] Schedule of Deferred Financing Cost Schedule of Derivative Interest Rate Swap Agreements [Table Text Block] Schedule Of Derivative Interest Rate Swap Agreements Table [Text Block] Derivative Interest Rate Agreements Schedule Of Earnings Per Share Basic And Diluted Table [Text Block] Earnings per Share Schedule Of Estimated Long Term Debt Repayments Table [Text Block] Schedule Of Estimated Long Term Debt Repayments Table [Text Block] Estimated Repayments of Long Term Debt Schedule of Fair Value of Derivative Instruments [Table Text Block] Schedule Of Fair Value Of Derivative Instruments Table [Text Block] Fair Value of Derivative Financial Instruments Schedule Of Finite Lived Intangible Assets [Table] Schedule of Finite-Lived Intangible Assets [Table] Schedule Of Intangible Assets Table [Text Block] Schedule Of Intangible Assets Table [Text Block] Schedule of Intangible Assets Schedule of intangible liabilities charter agreements. Schedule Of Intangible Liabilities Charter Agreements Table [Text Block] Schedule of Intangible Liability Schedule of Long Term Debt [Table Text Block] Schedule Of Long Term Debt Table [Text Block] Schedule of Long Term Debt Schedule of Other Operating Income Expense [Table Text Block] Schedule Of Other Operating Income Expense Table [Text Block] Schedule of Other Operating (Income) Expense Schedule Of Property Plant And Equipment [Table] Schedule of Property, Plant and Equipment [Table] Schedule Of Related Party Transactions By Related Party [Table] Schedule of Related Party Transactions, by Related Party [Table] Schedule Of Related Party Transactions Table [Text Block] Summary of Amounts Due to and from CMA CGM Companies Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table] Schedule of Share-based Compensation Arrangements by Share-based Payment Award [Table] Schedule Of Share Based Compensation Restricted Stock Units Award Activity Table [Text Block] Summary of Issued Share Based Awards Schedule Of Stock By Class [Table] Schedule of Stock by Class [Table] Schedule of vessels and their charters. Schedule Of Vessels And Charters Table [Text Block] Schedule of Vessels Chartered Segment [Domain] Segment [Domain] Segment Geographical [Domain] Segment, Geographical [Domain] Series A Preferred Stock [Member] Series A Preferred Stock [Member] The aggregate amount of settlement in the reporting period of interest rate derivatives which do not qualify for hedge accounting. Settlement Of Hedges Not Qualifying For Hedge Accounting Settlements of hedges which do not qualify for hedge accounting (note 14) Settlements of hedges which do not qualify for hedge accounting (note 14) Share Based Compensation Share based compensation (note 15) Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Grants In Period Weighted Average Grant Date Fair Value Granted ,Weighted Average Fair Value on Grant date Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Number Un-Vested, Number of Units Balance Unvested restricted stock units Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Nonvested Weighted Average Grant Date Fair Value Un-Vested ,Weighted Average Fair Value on Grant date Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Weighted Average Grant Date Fair Value Vested ,Weighted Average Fair Value on Grant date 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 Authorized Stock granted under Equity Incentive Plan Share Based Compensation Option And Incentive Plans Policy Share based compensation Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Significant Accounting Policies [Line Items] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Table] Significant Accounting Policies [Text Block] Significant Accounting Policies Software Development Additions Software Development Additions Addition - software development Statement Business Segments [Axis] Business Segments [Axis] Statement Class Of Stock [Axis] Class of Stock [Axis] Statement Equity Components [Axis] Equity Components [Axis] Statement Geographical [Axis] Geographical [Axis] Statement [Line Items] Statement [Line Items] Statement Of Cash Flows [Abstract] Statement of Cash Flows [Abstract] Statement Of Financial Position [Abstract] Statement of Financial Position [Abstract] Statement Of Partners Capital [Abstract] Statement of Partners' Capital [Abstract] Statement [Table] Statement [Table] Stockholders Equity Balance Balance Total Stockholders' Equity Stockholders Equity [Abstract] Stockholders' Equity Stockholders Equity Note Disclosure [Text Block] Share Capital Stock Issued During Period Shares New Issues Class A shares issued, shares (notes 13,15) Stock Issued During Period Value New Issues Class A shares issued (notes 13, 15) Subsequent Events [Abstract] Subsequent Events [Abstract] Subsequent Events [Text Block] Subsequent events Sundry Shipping Income [Member] Sundry Shipping Income [Member] Sundry shipping income [Member] Supplemental Cash Flow Information [Abstract] Supplemental Information Term Of Waiver For Leverage Ratio Term Of Waiver For Leverage Ratio Additional term of waiver for leverage ratio test Term of waiver for leverage ratio test Text Block [Abstract] Text Block [Abstract] Aggregate revenue during the reporting period from services rendered in the normal course of business, after deducting allowances and discounts and including amortization of charter agreement intangible liability. Time Charter Revenue Net Time charter revenue Title Of Individual With Relationship To Entity [Domain] Title of Individual with Relationship to Entity [Domain] Tonnage Tax Expense Included In Operating Expense Tonnage Tax Expense Included In Operating Expense Tonnage tax included within operating expenses Trading Symbol Trading Symbol Transfers And Servicing Of Financial Instruments Types Of Financial Instruments [Domain] Types of Financial Instruments [Domain] Unrealized loss or gain on interest rate derivatives which do not qualify for hedge accounting. Unrealized Gain Loss On Interest Rate Derivatives Unrealized gain (loss) on interest rate derivatives (note 14) Unrealized gain / (loss) on interest rate derivatives Use Of Estimates Use of estimates Vessel additions in period Vessel Additions Additions in the period Vessel Costs Capitalized And Depreciation And Amortization Expenses [Line Items] Vessel Costs Capitalized And Depreciation And Amortization Expenses [Line Items] Vessel Costs Capitalized And Depreciation And Amortization Expenses [Line Items] Vessel Depreciation Expense Vessel Depreciation Expense Depreciation expense Vessel Net Book Value Variations [Table Text Block] Vessel Net Book Value Variations Table [Text Block] Schedule of Variations in Net Book Value of Vessels Including Drydocking The aggregate vessel operating expenses incurred during the reporting period. Vessel Operating Expenses Vessel operating expenses Vessels Estimated Useful Life Vessels Estimated Useful Life Estimated useful life Vessels in Operation Cost Vessels In Operation Cost Cost Vessels in Operation less Accumulated Depreciation [Table Text Block] Vessels In Operation Less Accumulated Depreciation Table [Text Block] Schedule of Vessels in Operation Less Accumulated Depreciation Vessels In Operation Less Accumulated Depreciation [Text Block] Vessels In Operation Less Accumulated Depreciation [Text Block] Vessels in Operation, less Accumulated Depreciation The gross carrying amount of seagoing vessels used for the primary purpose of the carriage of cargo, including a drydock component, net of accumulated amortization and any impairment. Vessels In Operation Net Closing balance Opening balance Vessels in operation (note 4) Net book value Vessels Policy [Text Block] Vessels Policy [Text Block] Vessels Vested In January [Member] Vested In January [Member] Vested in January [Member] Vested In October [Member] Vested In October [Member] Vested in October [Member] Vested In September [Member] Vested In September [Member] Vested in September [Member] Ville D Aquarius [Member] Ville D Aquarius [Member] Ville d' Aquarius [Member] Ville D Orion [Member] Ville D Orion [Member] Ville d' Orion [Member] Voting Interest Voting Interest Voting Interest Warrants To Purchase Common Stock Exercise Price Warrants To Purchase Common Stock Exercise Price Exercise Price of Warrants Warrants To Purchase Common Stock Outstanding. Warrants To Purchase Common Stock Outstanding Warrants Outstanding Warrants To Purchase Common Stock Outstanding Expiry Date. Warrants To Purchase Common Stock Outstanding Expiry Date Warrants Outstanding Expiry Date Weighted Average Interest Swap Rate Weighted Average Interest Swap Rate Weighted average rate Weighted Average Number Of Diluted Shares Outstanding Diluted (note 17) Common shares and common share equivalents Weighted Average Number Of Shares Outstanding [Abstract] Weighted average number of common shares outstanding Weighted Average Number Of Shares Outstanding Basic Basic (note 17) Weighted average number of common shares outstanding Year Built Year Built Year Built Yildrim Group [Member] Yildrim Group [Member] Yildrim Group [Member]