Amendment Flag Current Fiscal Year End Date Document Fiscal Period Focus Document Fiscal Year Focus Document Period End Date Document Type Entity Central Index Key Entity Common Stock Shares Outstanding Entity Current Reporting Status Entity [Domain] Entity Filer Category Entity Registrant Name Entity Voluntary Filers Entity Well Known Seasoned Issuer Legal Entity [Axis] Trading Symbol Disclosure of accounting policy regarding recognition of voyage revenue and voyage and operating expenses. Accounting For Revenue Expenses Accounting for Revenue and Expenses: Disclosure of accounting policy forSpecial Survey and Dry-docking Costs. This accounting policy addresses: (1) the amortization method used; (2) the accounting for the unamortized portion; and (3) the accouting of such costs in case of a sale of vessel. Accounting For Special Survey Dry docking Costs Accounting for Special Survey and Dry-docking Costs: The value of the vessel acquired. Acquired Vessel Value Acquisition of newly constructed vessels Date of acquisition. Acquisitions Date Of Transaction For Acquisitions Date of vessel acquisition Affiliate Company [Member] Company affiliated with a non-executive member of the Board of Directors Aframax crude tanker under construction. Aframax Crude Tanker Under Construction 1 [Member] Aframax crude carrier Aframax crude tanker under construction. Aframax Crude Tanker Under Construction 2 [Member] Aframax crude carrier Aframax crude tanker under construction. Aframax Crude Tanker Under Construction 3 [Member] Aframax crude carrier Aframax crude tanker under construction. Aframax Crude Tanker Under Construction 4 [Member] Aframax crude carrier Aframax Maria Princess [Member] Aframax tanker Maria Princess Aframax Tanker 1 [Member] Aframax tanker 1 Aframax Tanker 2 [Member] Aframax tanker 2 Aframax Tanker 3 [Member] Aframax tanker 3 Aframax Tanker Elias Tsakos [Member] Aframax Tanker Elias Tsakos Aframax Tanker Marathon TS [Member] Aframax tanker Marathon TS Aframax tanker. Aframax Tanker [Member] Aframax tankers The related party AirMania Travel S.A. Air Mania Travel [Member] AirMania Travel S.A. Alaska [Member] Alaska All Company's term bank loans. All Term Loans [Member] All Company's term bank loans This element represents the amortization of deferred loss on dedesignated financial instruments. Losses reclassified to income Amortization Of Deferred Loss On Dedesignated Financial Instruments Amortization of deferred loss on de-designated financial instruments Amortization of de-designated hedging swap loss in accumulated other comprehensive income Amortization of deferred loss on the de-designated financial instruments Amortization of deferred loss on de-designated financial instruments The amount associated with the reassignment of a lease for newbuilding vessel. Amount From Cancellation Of Vessels Under Construction Prepaid amount which will be used against the contract price of future newbuildings Amphitrite [Member] Amphitrite Andromeda [Member] Andromeda The reflected interest which increases the monthly fees as per the Management Agreement, if both parties agree. Annual Increase Adjustment Of Monthly Management Fee Yearly increase basis Archangel [Member] Archangel The related party Argosy Insurance Company Limited. Argosy Insurance Company Limited [Member] Argosy Insurance Company Limited Argosy Insurance Limited Arion [Member] Arion Asahi Princess [Member] Aframax tanker Asahi Princess The charge against earnings associated with the log term bank loans. Bank charges An additional fee imposed by some loan agreements where a borrower retires a loan before its scheduled pay-off date. It is meant to compensate the lender for not realizing the anticipated interest income and for the possibility of reinvesting the loan amount at a lower interest rate. Breakage Cost Breakage cost Amount of commission revenue from brokerage services in relation to the charter of vessels on behalf of customers. Brokerage Services Commissions Revenue Brokerage commission revenue Fair value as of the balance sheet date of bunker call option derivative assets, net of bunker call option derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet. Bunker Call Option Derivatives At Fair Value Net Fair value of bunker call option agreements Bunker call options Bunker call option not designated as hedging instrument asset at fair value. Bunker Call Option Not Designated As Hedging Instrument Asset Fair Value Bunker call options - Asset Derivatives - Fair Value Bunker call option not designated as hedging instrument liability at fair value. Bunker Call Option Not Designated As Hedging Instrument Liability Fair Value Bunker call options - Liability Derivatives - Fair Value Amount of option premium for the bunker call option agreements. Bunker Call Option Premium Bunker call options premium Fair value as of the balance sheet date of bunker put option derivative assets, net of bunker put option derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet. Bunker Put Option Derivatives At Fair Value Net Bunker put options Fair value of bunker put option agreements Bunker put option not designated as hedging instrument asset at fair value. Bunker Put Option Not Designated As Hedging Instrument Asset Fair Value Bunker put options - Asset Derivatives - Fair Value Bunker put option not designated as hedging instrument liability at fair value. Bunker Put Option Not Designated As Hedging Instrument Liability Fair Value Bunker put options - Liability Derivatives - Fair Value Amount of option premium for the bunker put option agreements. Bunker Put Option Premium Bunker put options premium Fair value as of the balance sheet date of bunker swap derivative assets, net of bunker swap derivative liabilities, which includes all such derivative instruments in hedging and nonhedging relationships that are recognized on the balance sheet. Bunker Swap Derivatives At Fair Value Net Bunker swaps Fair value of bunker swap agreement Bunker swaps not designated as hedging instruments asset at fair value. Bunker Swaps Not Designated As Hedging Instruments Asset At Fair Value Bunker swaps - Asset Derivatives - Fair Value Bunker swaps not designated as hedging instruments liability at fair value. Bunker Swaps Not Designated As Hedging Instruments Liability At Fair Value Bunker swaps - Liability Derivatives - Fair Value Amount of interest costs incurred during swap settlements for bunkers swaps designated as non hedging. Bunkers Swap Cash Settlements Non Hedging Bunkers swap and call options cash settlements The amount of payment as penalty under the Management Agreement for the termination of contract if a member of BoD is elected to the Holding Company's Board of Directors without having been recommended by the existing board. Cancellation Of Management Agreement Penalty Fee Compensation to Management company after contract termination with Directors Capital contribution to subsidiary. Capital Contribution To Subsidiary Capital contribution to subsidiary by Tsakos Energy Navigation Limited Carrying Amount Of Long Term Debt [Member] Carrying amount of one long-term bank loan The expected decrease in the annual depreciation expense per weighted average number of shares, basic and diluted, due to the change in accounting estimate. Change In Accounting Estimate Effect On Depreciation Per Weighted Average Number Of Shares Change in accounting estimate effect on depreciation per weighted average number of shares The expected decrease in the annual depreciation expense due to the change in accounting estimate. Change In Accounting Estimate Effect On Depreciation Change in accounting estimate effect on depreciation The expected decrease in net income due to the change in accounting estimate. Change In Accounting Estimate Financial Effect 1 Change in accounting estimate financial effect The expected decrease in net income per weighted average number of shares, both basic and diluted, due to the change in accounting estimate. Change In Accounting Estimate Financial Effect Per Weighted Average Number Of Shares Change in accounting estimate financial effect per weight average number of shares Date the charter hire agreement was signed. Charter Hire Agreement Date Of Agreement Date of agreement The amount charged as daily charter hire. Charter Hire Daily Rate Charter hire daily rate Chartered In Or On Bareboat Basis [Member] Chartered in or on bare-boat basis Chartered out vessels or on a bare-boat basis. Chartered Out Vessels Or On Bareboat Basis [Member] Vessels chartered out on a bare-boat basis Reflects the percentage that revenues in the period from a significant customer is to net revenues, as defined by the entity, such as total net revenues, product line revenues, segment revenues. Charterer B [Member] Charterer B Reflects the percentage that revenues in the period from a significant customer is to net revenues, as defined by the entity, such as total net revenues, product line revenues, segment revenues. Charterer C [Member] Charterer C Reflects the percentage that revenues in the period from a significant customer is to net revenues, as defined by the entity, such as total net revenues, product line revenues, segment revenues. Charterer D [Member] Charterer D Reflects the percentage that revenues in the period from a significant customer is to net revenues, as defined by the entity, such as total net revenues, product line revenues, segment revenues. Charterer A [Member] Charterer A Commercial And Kexim Facilities [Member] Commercial and Kexim facilities components Commercial And Non Commercial Facility [Member] Commercial and non-commercial facility Commercial Facility [Member] Commercial Facility Payment for the commission as a percentage on the price, paid to Managers for the purchase or sale of a vessel. Commission On Purchase On Sale Price Of Vessels Amount Brokerage commission amount This item represents the commission as a percentage on the price, paid to Managers for the purchase or sale of a vessel. Commission On Purchase On Sale Price Of Vessels Brokerage commission Cost of payment on delivery of new-buildings for the cost of design and supervision of the new buildings by Tsakos Shipping. Commissions In Connection With Delivery Of New Buildings Payment for the cost of design and supervision services for newbuildings Fee for the provision of design and supervision services by Tsakos shipping for each new building. Commissions In Connection With Delivery Of Each New Building Charge fee Payment for the cost of design and supervision services for each newbuilding vessel This item represents the commission as a percentage paid to Managers on charter hire agreements. Commissions On Charter Hire Agreements Chartering commission The amount paid as brokerage or address commission on chartering arrangements. Commissions Tsakos Shipping and Trading S.A. (commissions) Aggregate dividends paid during period for each share of common stock outstanding. Common Stock Dividends Per Share Cash Paid 1 Cash dividends paid, per share The description of increase in base dividend rate following the covenant cross-default, dividend payment default or failure to redeem. Conditions For Dividend Rate Increase Conditions for dividend rate increase Credit facility. Credit Facility 1 [Member] Credit facility Credit facility. Credit Facility 2 [Member] Credit facility Credit facility with outstanding balance $31,594 as at December 31, 2017 Credit facility. Credit Facility 3 [Member] Credit facility Credit facility. Credit Facility 4 [Member] Credit facility Credit facility. Credit Facility 5 [Member] Credit facility Credit facility. Credit Facility 6 [Member] Credit facility Credit facility. Credit Facility 7 [Member] Credit facility Credit facility with outstanding balance $72,500 as at December 31, 2016 Credit facility. Credit Facility 8 [Member] Credit facility Crude carriers. Crude Carriers [Member] Crude Carriers Current Portion Of Financial Instruments Fair Value [Member] Current portion of financial instruments - Fair Value This element represents the number of days required in order for a written notice to be sent for the cancellation of the consultancy agreement, if even one director is elected to the entity's Board of Directors (BoD) without being recommended by the previous Board. Days Required For Cancellation Written Notice For Agreement Days required for cancellation written notice for agreement Tabular disclosure of debt. Debt Disclosure [Table Text Block] Debt Disclosure Current amount, before unamortized (discount) premium and debt issuance costs, of long-term debt. Debt Instrument Carrying Amount Current Less current portion of debt The maximum amount of borrowing under the debt instrument that is available as a percentage of vessels value. Debt Instrument Maximum Face Amount As Percentage Of Vessels Value Debt instrument maximum Face Amount as percentage of vessels value The date the debt instrument was issued. Debt Instrument Origination Date Origination Date Debt instrument origination date Amount of the required periodic payments including both interest and principal payments, as a proportion of the amount drawn down. Debt Instrument Periodic Payment Ratio Debt periodic payment amount, proportion to amount drawn down De-designated hedging swap loss in accumulated other comprehensive income. Dedesignation Of Cash Flow Hedge Loss In Accumulated Other Comprehensive Income De-designated hedging swap loss in accumulated other comprehensive income Deferred charges, consisted of dry-docking and special survey costs, net of accumulated amortization. Deferred Charges Net Deferred charges consisted of dry-docking and special survey costs The entire disclosure for deferred charges. This disclosure includes deferred charges consisted of dry docking and special survey costs and loan fees, net and amortization expense. Deferred Charges Text Block Deferred Charges Primary financial statement caption encompassing depreciation expense. Depreciation Expense [Member] Depreciation expense The portion of gains and losses (net) on derivative instruments not designated as hedging instruments recognized in earnings. Derivative Instruments Not Designated As Hedging Instruments Gain Loss Recognized In Income Total Aggregate notional amount of interest rate derivatives, which relates to the currency amount specified in the interest rate derivative instruments. Derivative Notional Amount 1 Notional amount of floating-to-fixed interest rate swaps Distribution agency agreement. Distribution Agency Agreement [Member] Distribution Agency Agreement The amount of dividends declared, but not paid, during the reporting period. Dividends Declared Cash dividends declared ($0.06 per share) Document And Entity Information [Abstract] Eight Loans [Member] Certain of the loan agreements Eight year term bank loan. Eight Year Term Loan 2 [Member] 8-year term loan Eight year term bank loan. Eight Year Term Loan 3 [Member] 8-year term loan Eight Year Term Loan 4 [Member] 8-year term loan Eight year term bank loan. Eight Year Term Loan [Member] 8-year term loan Eurochampion And Euronike [Member] Eurochampion 2004 and Euronike Eurochampion Maria Princess And Ulysses [Member] Suezmax Eurochampion 2004, aframax Maria Princess and VLCC Ulysses Fair value of assets and liabilities measured on recurring basis. Fair Value Assets And Liabilities Measured On Recurring Basis Total Fair value of bunker swap agreements. Fair Value Of Bunker Swap Agreements Fair value of bunker swap agreement Total finance project costs charged against earnings. Finance Project Costs Expensed Finance project costs expensed Financial Instruments Fair Value Net Of Current Portion [Member] Financial instruments - Fair Value, net of current portion First 15 Years [Member] First 15 years of vessel's life First Four Installments [Member] First four installments First [Member] First First Tranch [Member] First Tranch Five Aframax tankers under construction. Five Aframax Tankers Under Construction [Member] Five Aframax Tankers Under Construction Five Year Term Loan 1 [Member] 5-year term loan Five Year Term Loan 2 [Member] 5-year term loan Five Year Term Loan [Member] 5-year term loan Four of the entity's loan agreements. Four Loan Agreements [Member] Four loan agreements Four Year Term Loan [Member] 4-year term loan Gain or (loss) on bunker call option derivative instruments not designated as hedging instruments. Gain Loss On Bunker Call Option Derivative Instruments Not Designated As Hedging Instruments Bunker call options Gain or (loss) on bunker put option derivative instruments not designated as hedging instruments. Gain Loss On Bunker Put Options Derivative Instruments Not Designated As Hedging Instruments Bunker put options Gain or (loss) on bunker swaps derivative instruments not designated as hedging instruments. Gain Loss On Bunker Swaps Derivative Instruments Not Designated As Hedging Instruments Bunker swaps Primary financial statement caption encompassing gains (losses) on derivative instruments. Gain Loss Recognized In Accumulated Other Comprehensive Income Loss On Derivative Effective Portion [Member] Gain/(Loss) Recognized in Accumulated OCI on Derivative (Effective Portion) Difference between the fair value amount and the carrying amount of debt which is extinguished prior to maturity. Gains Losses On Extinguishment Of Debt 1 Gain on extinguishment of debt Fees charged to the management company, related to services such as ticketing, insurance contracts etc. General Services Costs AirMania Travel S.A. (travel services) Travel services Handysize Tanker Delphi And Suezmax Tanker Triathlon [Member] Handysize tanker Delphi and Suezmax tanker Triathlon Handysize Tanker Delphi [Member] Handysize tanker Delphi Handysize Tankers Byzantion And Bosporos [Member] Handysize tankers Byzantion and Bosporos Hercules I [Member] VLCC Hercules I VLCC tanker Hercules I Marathon TS, Sola, Oslo TS, Stavanger and Bergen [Member] Aframaxes Marathon TS, Sola TS, Oslo TS, Stavanger TS and Bergen TS The entire disclosure for interest and finance costs, net. This disclosure includes interest and finance expense, amortization expense, interest capitalized, swap settlements and changes in fair value of non hedging financial instruments. Interest Finance Costs Net Text Block Interest and Finance Costs, net Amount of interest costs incurred during swap settlements for interest rate swaps designated as non hedging. Interest Rate Swap Cash Settlements Non Hedging Interest swap cash settlements non-hedging Issuance of common stock under distribution agency agreement. Issuance Of Common Stock Under Distribution Agency Agreement Issuance of common stock under distribution agency agreement Izumo Princess And Aegeas [Member] Izumo Princess and Aegeas Kexim Facility [Member] Kexim Facility LNG Maria Energy [Member] LNG Maria Energy LR1 Product Carrier 2 [Member] LR1 product carrier 2 Long Range 1 (LR1) product tanker. Large Range 1 Product Tanker [Member] LR1 product tankers Large Range 1 (LR1) product tanker under construction. Large Range 1 Product Tanker Under Construction 1 [Member] LR1 product carrier LR1 Tanker Under Construction Large Range 1 (LR1) product tanker under construction. Large Range 1 Product Tanker Under Construction 2 [Member] LR1 product carrier LR1 Tanker Under Construction Last [Member] Last Liquefied Natural Gas Carrier. Liquefied Natural Gas Carrier [Member] LNG Carriers Liquefied Natural Gas carrier under construction. Liquefied Natural Gas Carrier Under Construction [Member] LNG Carrier Under Construction LNG Carrier Maria Energy Two of the entity's loan agreements. Loan Facility1 And Loan Facility2 [Member] Two Loan Facilities Loan not in compliance with value-to-loan ratio requirement. Loans Not In Compliance With Value To Loan Ratio [Member] Term loan not in compliance with value-to-loan ratio Estimated future management fees payable in the remainderof the fiscal year, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable RemainderOf Fiscal Year July to December 2017 Total estimated future management fees payable under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Total Total Estimated future management fees payable in the fifth fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year Five 2022 Estimated future management fees payable in the fourth fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year Four 2021 Estimated future management fees payable in the next fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year One 2018 Estimated future management fees payable after the fifth fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year Six And After 2023 to 2027 Estimated future management fees payable in the third fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year Three 2020 Estimated future management fees payable in the second fiscal year following the latest fiscal year ended, under the Management Agreement, exclusive of any incentive awards and based on existing vessels and new vessels scheduled for future delivery. Management Fee Payable Year Two 2019 Fees charged and capitalized upon construction of newbuildings, which are related to management fees. Management Fees Capitalized Supervisory services The amount awarded to the Management Company based on the Holding Company's annual return on equity, or any other special contribution. Management Incentive Award Management incentive award The entire disclosure for marketable securities. Marketable Securities Disclosure [Text Block] Marketable securities The maximum number of common shares permitted to be issued under the distribution agency agreement. Maximum Number Of Shares Issuable Under Distribution Agency Agreement Maximum number of shares issuable under distribution agency agreement Maya Inca [Member] Two 2003-built LR1s, Maya and Inca Millenium Euronike And Eurochampion [Member] Millenium, Euronike and Eurochampion 2004 The annual appreciation of Euro against Dollar, above which an adjustment of the monthly fees as per the Management Agreement applies. Minimum Appreciation Euro Dollar Triggering Adjustment Of Monthly Management Fee Euro appreciated against dollar percentage Tabular disclosure for the charter-out agreements, including the future minimum revenues of vessels in operation before reduction for the commissions, expected to be recognized on non-cancelable time charters. Minimum Future Charter Revenues [Table Text Block] Minimum Future Charter Revenue The minimum liquidity required to be maintained by covenants. Minimum Liquidity Covenant Requirement [Member] Minimum liquidity requirement Supervisory services monthly fee per vessel. Monthly Construction Supervisory Fee Per Vessel Monthly fee for supervisory services, per vessel Professional and contract service expense per month for operating vessels. Monthly Management Fees Monthly management fees Amount of the effect of a change in accounting principle regarding debt issuance costs, on current portion of long-term debt, net, retrospective adoption for the period presented. New Accounting Pronouncement Or Change In Accounting Principle Effect Of Change On Current Portion Long Term Debt Net New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Current Portion of Long-Term Debt, net Amount of the effect of a change in accounting principle regarding debt issuance costs, on deferred charges, net, retrospective adoption for the period presented. New Accounting Pronouncement Or Change In Accounting Principle Effect Of Change On Deferred Charges Net New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Deferred charges, net Amount of the effect of a change in accounting principle regarding debt issuance costs, on long-term debt, net, retrospective adoption for the period presented. New Accounting Pronouncement Or Change In Accounting Principle Effect Of Change On Long Term Debt Net New Accounting Pronouncement or Change in Accounting Principle, Effect of Change on Long-Term Debt, net Amount of the effect of a change in accounting principle per weighted average number of shares, basic and diluted. New Accounting Pronouncement Or Change In Accounting Principle Effect Of Change Per Weighted Average Number Of Shares Both Basic And Diluted Earnings Per Share Change in accounting estimate effect, decrease per weighted average number of shares basic and diluted Newbuild Aframaxes [Member] Aframaxes Elias Tsakos, Thomas Zafiras, Leontios H and Parthenon TS Description of the new contract agreed between the entity and a shipbuilding yard. New Contract With Yard New contract with yard New Twelve Year Loan [Member] Two facilities new loan Nine year term bank loan. Nine Year Term Loan 2 [Member] 9-year term loan Nine year term bank loan. Nine Year Term Loan [Member] 9-year term loan Nineteen month term bank loan. Nineteen Month Term Loan [Member] 19-month term loan Non Commercial Facility [Member] Non-commercial facility The number of semi-annual installments. Number Loan Tranches Number of loan tranches Number of bunker call option agreements entered into. Number Of Bunker Call Option Agreements Entered Into Number of bunker call option agreement entered into Number of bunker call option agreements expired. Number Of Bunker Call Option Agreements Expired Number of bunker call options agreements expired Number of bunker call option agreements held by the entity at the reporting date. Number Of Bunker Call Option Agreements Held Number of bunker call option agreements held Number of bunker put option agreements held by the entity at the reporting date. Number Of Bunker Put Option Agreements Held Number of bunker put option agreements held Number of bunker swap agreements entered into. Number Of Bunker Swap Agreements Entered Into Number of bunker swap agreements entered into Number of bunker swap agreements held by the entity at the reporting date. Number Of Bunker Swap Agreements Held Number of bunker swap agreements held Number of credit facilities with reducing revolving credit component and term bank loan component. Number Of Credit Facilities With Reducing Revolving Credit Component And Term Bank Loan Component Number of credit facilities with both a reducing revolving credit component and a term bank loan component, with balloon payments due at maturity between October 2018 and April 2019 Number of interest rate swaps terminated. Number Of Interest Rate Swaps Terminated Number of interest rate swaps terminated