XML 25 R42.htm IDEA: XBRL DOCUMENT
v2.4.0.8

RELATED PARTY TRANSACTIONS (Details) (USD $) | 0 Months Ended | 12 Months Ended
--- | --- | ---
Jan. 10, 2013 | Dec. 31, 2013 Person | Dec. 31, 2012 | Dec. 31, 2011 Person
Related Party Transaction [Line Items] |  |  |  |
Costs and expenses, related party |  | $ 0 | $ 3,930,000 | $ 3,821,000
Number of tankers withdrawn from pool |  |  | 9 |
Private equity placement issued amount |  | 172,611,000 | 75,582,000 |
Investment in Nordic American Offshore Ltd |  | 64,128,000 | 0 |
Warrants received (in shares) |  | 833,333 |  |
Warrants exercise price (n dollars per share) |  | $ 15.00 |  |
Percentage of warrants vesting increments (in hundredths) |  | 20.00% |  |
Percentages of increase in volume weighted average price (in hundredths) |  | 10.00% |  |
Minimum business days required for exercise level of VWAP |  | 10 days |  |
VWAP minimum trading volume of exercise levels |  | 2,000,000 |  |
Minimum [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage of common shares increase (in hundredths) |  | 25.00% |  |
Maximum [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Percentage of common shares increase (in hundredths) |  | 65.00% |  |
Percentage of NAO's common shares increases, maximum (in hundredths) |  | 65.00% |  |
Scandic American Shipping Ltd [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Manager's right to ownership of company's total outstanding shares (in hundredths) |  |  | 2.00% |
Acquisition of shares in percentage (in hundredths) | 100.00% |  |  |
New amount of management fee due to decrease/increase in the period |  | 150,000 |  | 500,000
Previous amount of management fee before decrease/increase in the period |  | 500,000 |  | 350,000
Accounts payable |  |  | 1,500,000 |
Restricted shares authorized (in shares) |  |  |  | 400,000
Individuals in management and board members participating in incentive plan |  | 17 |  | 23
Allocated restricted common shares subject to vesting (in shares) |  | 203,000 |  |
Restricted shares issued to the Manager (in shares) | 174,000 |  |  |
Share-based compensation expense | 1,100,000 |  |  |
Former Director [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Accounts payable |  | 5,000 | 0 |
Costs and expenses, related party |  | 100,000 | 100,000 | 100,000
Advisor to the Chairman [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Accounts payable |  | 10,000 | 0 |
Costs and expenses, related party |  | 100,000 | 100,000 | 100,000
Orion Tankers Pool [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Number of tankers withdrawn from pool |  |  | 9 |
Related party receivable |  |  | 37,000,000 |
Initial funding per vessel |  |  | 200,000 |
Accounts receivable, net related party |  |  | 12,900,000 |
Nordic American Offshore Limited [Member] | Private Placement [Member] |  |  |  |
Related Party Transaction [Line Items] |  |  |  |
Private equity placement issued amount |  | 250,000,000 |  |
Investment in Nordic American Offshore Ltd |  | $ 65,000,000 |  |
Private equity placement participation (in hundredths) |  | 26.00% |  |

X
- Definition Restricted common shares subject to vesting that are allocated to persons employed in management of the entity. + References No definition available. + Details
Name: | nat_AllocatedRestrictedCommonSharesSubjectToVesting
Namespace Prefix: | nat_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Factor defining the numbers of common shares the manager is entitled upon qualifying events (e.g. initial adoption of management agreement and subsequent share issues). + References No definition available. + Details
Name: | nat_DueToRelatedPartiesManagersRightToOwnershipOfCompanysTotalOutstandingShares
Namespace Prefix: | nat_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition The number of individual in management and Board members participating in incentive plan. + References No definition available. + Details
Name: | nat_IndividualsInManagementAndBoardMembersParticipatingInIncentivePlan
Namespace Prefix: | nat_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition The amount, per vessel, added to the value of bunkers on board the company's vessels at the time of delivery to the Cooperative Arrangement to obtain the amount of working capital under cooperative arrangements. + References No definition available. + Details
Name: | nat_InitialFundingPerVessel
Namespace Prefix: | nat_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents minimum business days required for exercise level. + References No definition available. + Details
Name: | nat_MinimumBusinessDaysRequiredForExerciseLevel
Namespace Prefix: | nat_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents minimum trading volume of exercise levels on balance sheet date. + References No definition available. + Details
Name: | nat_MinimumTradingVolumeOfExerciseLevels
Namespace Prefix: | nat_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition The total number of tankers withdrawn from pool during the period, which may include crude oil tankers and new vessels under construction to be used in the normal conduct of business and not intended for resale. + References No definition available. + Details
Name: | nat_NumberOfTankersWithdrawnFromPool
Namespace Prefix: | nat_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents percentage of common shares increase during the period. + References No definition available. + Details
Name: | nat_PercentageOfCommonSharesIncrease
Namespace Prefix: | nat_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Refers to Percentage of NAO's common shares increases, maximum. + References No definition available. + Details
Name: | nat_PercentageOfNaoSCommonSharesIncreasesMaximumInHundredths
Namespace Prefix: | nat_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Represents percentage of warrants vesting increments during the period. + References No definition available. + Details
Name: | nat_PercentageOfWarrantsVestingIncrements
Namespace Prefix: | nat_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Represents percentages of increase in volume weighted average price during the period. + References No definition available. + Details
Name: | nat_PercentagesOfIncreaseInVolumeWeightedAveragePrice
Namespace Prefix: | nat_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition New amount of management fee due to (decrease) increase during the period. + References No definition available. + Details
Name: | nat_RelatedPartyTransactionNewAmountOfManagementFeeDueToDecreaseIncreaseInPeriod
Namespace Prefix: | nat_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Old amount of management fee before (decrease) increase during the period. + References No definition available. + Details
Name: | nat_RelatedPartyTransactionPreviousAmountOfManagementFeeBeforeDecreaseIncreaseInPeriod
Namespace Prefix: | nat_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of receivables arising from transactions with related parties due within one year or the normal operating cycle, if longer. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.3(a)(2)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AccountsReceivableRelatedPartiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Amount of receivables arising from transactions with related parties, due after 1 year (or 1 business cycle). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39622-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39603-107864 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 3 -Subparagraph a -Article 5 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.11) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AccountsReceivableRelatedPartiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Represents the expense recognized during the period arising from equity-based compensation arrangements (for example, shares of stock, unit, stock options or other equity instruments) with employees, directors and certain consultants qualifying for treatment as employees. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5047-113901 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SAB TOPIC 14.F) -URI http://asc.fasb.org/extlink&oid=27013229&loc=d3e301413-122809 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (h)(1)(i) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Staff Accounting Bulletin (SAB) -Number Topic 14 -Section F + Details
Name: | us-gaap_AllocatedShareBasedCompensationExpense
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Percentage of voting equity interests acquired at the acquisition date in the business combination. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 805 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=25497992&loc=d3e1392-128463 + Details
Name: | us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Exercise price per share or per unit of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)(4)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Subparagraph 4 -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights
Namespace Prefix: | us-gaap_
Data Type: | us-types:perUnitItemType
Balance Type: | na
Period Type: | instant

X
- Definition Number of warrants or rights outstanding. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(i)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph i -Article 4 + Details
Name: | us-gaap_ClassOfWarrantOrRightOutstanding
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Costs of sales and operating expenses for the period incurred from transactions with related parties. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 225 -SubTopic 10 -Section S99 -Paragraph 2 -Subparagraph (SX 210.5-03.2) -URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688 + Details
Name: | us-gaap_CostsAndExpensesRelatedParty
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Carrying amount as of the balance sheet date of obligations due all related parties. For classified balance sheets, represents the current portion of such liabilities (due within one year or within the normal operating cycle if longer). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(k)(1)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 850 -SubTopic 10 -Section 50 -Paragraph 1 -Subparagraph (d) -URI http://asc.fasb.org/extlink&oid=6457730&loc=d3e39549-107864 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph k -Subparagraph 1 -Article 4 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 19 -Subparagraph a -Article 5 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.19(a)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_DueToRelatedPartiesCurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The percentage of ownership of common stock or equity participation in the investee accounted for under the equity method of accounting. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 + Details
Name: | us-gaap_EquityMethodInvestmentOwnershipPercentage
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The amount of noncurrent assets reported by an equity method investment of the entity. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 235 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.4-08.(g)) -URI http://asc.fasb.org/extlink&oid=26873400&loc=d3e23780-122690 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 3 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33918-111571 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 323 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6382943&loc=d3e33912-111571 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 825 -SubTopic 10 -Section 50 -Paragraph 28 -Subparagraph (f) -URI http://asc.fasb.org/extlink&oid=6957238&loc=d3e14064-108612 Reference 5: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph bb -Article 1 Reference 6: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 08 -Paragraph g -Subparagraph 1, 2 -Article 4 Reference 7: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph w -Article 1 + Details
Name: | us-gaap_EquityMethodInvestmentSummarizedFinancialInformationNoncurrentAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Details
Name: | us-gaap_RelatedPartyTransactionLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition The maximum number of shares (or other type of equity) originally approved (usually by shareholders and board of directors), net of any subsequent amendments and adjustments, for awards under the equity-based compensation plan. As stock or unit options and equity instruments other than options are awarded to participants, the shares or units remain authorized and become reserved for issuance under outstanding awards (not necessarily vested). + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 10 -Section 50 -Paragraph 2 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901 + Details
Name: | us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | instant

X
- Definition Gross number of shares (or other type of equity) issued during the period as a result of any equity-based compensation plan other than an employee stock ownership plan (ESOP). Shares issued could result from the issuance of restricted stock, the exercise of stock options, stock issued under employee stock purchase plans, and/or other employee benefit plans. + References No definition available. + Details
Name: | us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensationGross
Namespace Prefix: | us-gaap_
Data Type: | xbrli:sharesItemType
Balance Type: | na
Period Type: | duration

X
- Definition Equity impact of the value of new stock issued during the period. Includes shares issued in an initial public offering or a secondary public offering. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 04 -Article 3 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section 50 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21463-112644 Reference 3: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 505 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.3-04) -URI http://asc.fasb.org/extlink&oid=27012166&loc=d3e187085-122770 Reference 4: http://www.xbrl.org/2003/role/presentationRef -Publisher SEC -Name Regulation S-X (SX) -Number 210 -Section 02 -Paragraph 29, 30, 31 -Article 5 + Details
Name: | us-gaap_StockIssuedDuringPeriodValueNewIssues
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration