XML 95 R75.htm IDEA: XBRL DOCUMENT
v3.8.0.1

Indebtedness - Senior Debt Notes - Additional Information (Detail) $ in Thousands, kr in Millions |  |  |  |  | 1 Months Ended | 9 Months Ended | 12 Months Ended |
--- | --- | --- | --- | --- | --- | --- | --- | ---
Jul. 31, 2017 USD ($) Vessel | Nov. 15, 2013 USD ($) | Sep. 30, 2013 USD ($) | Aug. 15, 2011 USD ($) | May 27, 2015 USD ($) | Mar. 31, 2015 USD ($) | Jan. 31, 2014 NOK (kr) | May 31, 2012 NOK (kr) | Dec. 31, 2017 USD ($) | Mar. 31, 2011 USD ($) | Dec. 31, 2017 NOK (kr)
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Aggregate principal amount | $ 350,000 |  |  |  |  |  |  |  |  |  |
Debt instrument outstanding amount |  |  |  |  |  |  |  |  | $ 448,160 |  |
Notes Due May 2024 |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, month and year |  |  |  |  |  |  |  | 2024-05 |  |  |
Aggregate principal amount | kr |  |  |  |  |  |  |  | kr 204.4 |  |  |
Indebtedness rate |  |  |  |  |  |  | 1.25% |  |  |  |
Indebtedness sub-tranche premium rate |  |  |  |  |  |  | 1.00% |  |  |  |
Total capitalization rate |  |  |  |  |  |  | 6.13% |  |  |  |
Debt instrument outstanding amount |  |  |  |  |  |  |  |  | 14,100 |  | kr 115.0
Debt instrument fixed interest rate |  |  |  |  |  |  |  | 3.88% |  |  |
September 2013 Senior Unsecured Notes |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Senior note issuable amount under purchase agreement |  |  | $ 500,000 |  |  |  |  |  |  |  |
Sale of debt outstanding |  | $ 200,000 | $ 300,000 |  |  |  |  |  | $ 500,000 |  |
September 2013 Senior Unsecured Notes | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 7 years |  |
September 2013 Senior Unsecured Notes | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 12 years |  |
August 2011 Senior Unsecured Notes |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Sale of debt outstanding |  |  |  | $ 165,000 |  |  |  |  |  |  |
August 2011 Senior Unsecured Notes | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 8 years |  |
August 2011 Senior Unsecured Notes | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 10 years |  |
September 2010 Senior Unsecured Notes |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Sale of debt outstanding |  |  |  |  |  |  |  |  |  | $ 425,000 |
September 2010 Senior Unsecured Notes | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 5 years |  |
September 2010 Senior Unsecured Notes | Maximum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, in years |  |  |  |  |  |  |  |  | 12 years |  |
Troms Offshore Supply AS | Notes Due April 2027 |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, month and year |  |  |  |  | 2027-04 |  |  |  |  |  |
Aggregate principal amount |  |  |  |  | $ 31,300 |  |  |  |  |  |
Debt instrument bearing floating interest rate |  |  |  |  | 2.92% |  |  |  |  |  |
Indebtedness rate |  |  |  |  | 1.00% |  |  |  |  |  |
Indebtedness sub-tranche premium rate |  |  |  |  | 1.00% |  |  |  |  |  |
Total capitalization rate |  |  |  |  | 4.92% |  |  |  |  |  |
Debt instrument outstanding amount |  |  |  |  |  |  |  |  | $ 25,500 |  |
Troms Offshore Supply AS | Notes Due January 2027 |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, month and year |  |  |  |  |  | 2027-01 |  |  |  |  |
Aggregate principal amount |  |  |  |  |  | $ 29,500 |  |  |  |  |
Debt instrument bearing floating interest rate |  |  |  |  |  | 2.91% |  |  |  |  |
Indebtedness rate |  |  |  |  |  | 1.00% |  |  |  |  |
Indebtedness sub-tranche premium rate |  |  |  |  |  | 1.00% |  |  |  |  |
Total capitalization rate |  |  |  |  |  | 4.91% |  |  |  |  |
Debt instrument outstanding amount |  |  |  |  |  |  |  |  | 23,300 |  |
Troms Offshore Supply AS | Notes Due January 2026 |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument maturity, month and year |  |  |  |  |  |  | 2026-01 |  |  |  |
Aggregate principal amount | kr |  |  |  |  |  |  | kr 300.0 |  |  |  |
Indebtedness rate |  |  |  |  |  |  | 1.25% |  |  |  |
Indebtedness sub-tranche premium rate |  |  |  |  |  |  | 1.00% |  |  |  |
Total capitalization rate |  |  |  |  |  |  | 4.56% |  |  |  |
Debt instrument outstanding amount |  |  |  |  |  |  |  |  | $ 26,000 |  | kr 212.5
Troms Offshore Supply AS | Notes Due January 2026 | Minimum |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Debt instrument bearing floating interest rate |  |  |  |  |  |  | 2.31% |  |  |  |
Troms Offshore Supply AS | Plan of Reorganization | Senior Notes |  |  |  |  |  |  |  |  |  |  |
Debt [Line Items] |  |  |  |  |  |  |  |  |  |  |
Plan effective date | Jul. 31, 2017 |  |  |  |  |  |  |  |  |  |
Modification description of debt instrument | (i) reduce by 50% the required principal payments due from the Effective Date through March 31, 2019, (ii) modestly increase the interest rates on amounts outstanding through April 2023, and (iii) provide for security and additional guarantees, including (a) mortgages on six vessels and related assignments of earnings and insurances, (b) share pledges by Troms Offshore and certain subsidiaries of Troms Offshore, and (c) guarantees by certain subsidiaries of Troms Offshore. |  |  |  |  |  |  |  |  |  |
Percentage of required principal payments due from effective date | 50.00% |  |  |  |  |  |  |  |  |  |
Number of vessels mortgaged | Vessel | 6 |  |  |  |  |  |  |  |  |  |

X
- Definition Capitalization Rate + References No definition available. + Details
Name: | tdw_CapitalizationRate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition Debt Instrument Aggregate Rate + References No definition available. + Details
Name: | tdw_DebtInstrumentAggregateRate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt Instrument, Maturity, Month and Year + References No definition available. + Details
Name: | tdw_DebtInstrumentMaturityMonthAndYear
Namespace Prefix: | tdw_
Data Type: | xbrli:gYearMonthItemType
Balance Type: | na
Period Type: | duration

X
- Definition Debt instrument sub-tranche premium rate. + References No definition available. + Details
Name: | tdw_DebtInstrumentSubTranchePremiumRate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Modification description of debt instrument. + References No definition available. + Details
Name: | tdw_ModificationDescriptionOfDebtInstrument
Namespace Prefix: | tdw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Notes Issuable In Exchange, Face Amount + References No definition available. + Details
Name: | tdw_NotesIssuableInExchangeFaceAmount
Namespace Prefix: | tdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Number of vessels mortgaged. + References No definition available. + Details
Name: | tdw_NumberOfVesselsMortgaged
Namespace Prefix: | tdw_
Data Type: | xbrli:integerItemType
Balance Type: | na
Period Type: | instant

X
- Definition Percentage of required principal payments due from effective date. + References No definition available. + Details
Name: | tdw_PercentageOfRequiredPrincipalPaymentsDueFromEffectiveDate
Namespace Prefix: | tdw_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | duration

X
- Definition Prepackaged plan effective date. + References No definition available. + Details
Name: | tdw_PrepackagedPlanEffectiveDate
Namespace Prefix: | tdw_
Data Type: | xbrli:dateItemType
Balance Type: | na
Period Type: | duration

X
- Definition Face (par) amount of debt instrument at time of issuance. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 55 -Paragraph 8 -URI http://asc.fasb.org/extlink&oid=64930739&loc=d3e28878-108400 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 835 -SubTopic 30 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=64930785&loc=d3e28551-108399 + Details
Name: | us-gaap_DebtInstrumentFaceAmount
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentLineItems
Namespace Prefix: | us-gaap_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Period of time between issuance and maturity of debt instrument, in PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days. + References No definition available. + Details
Name: | us-gaap_DebtInstrumentTerm
Namespace Prefix: | us-gaap_
Data Type: | xbrli:durationItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount, after unamortized (discount) premium and debt issuance costs, of long-term debt. Includes, but not limited to, notes payable, bonds payable, debentures, mortgage loans and commercial paper. Excludes capital lease obligations. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(16)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 2: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(16)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 3: 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(22)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a set, unchanging rate. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtPercentageBearingFixedInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The interest rate applicable to the portion of the carrying amount of long-term borrowings outstanding as of the balance sheet date, including current maturities, which accrues interest at a rate subject to change from time to time. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02.22(a)(1)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_LongTermDebtPercentageBearingVariableInterestRate
Namespace Prefix: | us-gaap_
Data Type: | num:percentItemType
Balance Type: | na
Period Type: | instant

X
- Definition The cash inflow from the issuance of long-term debt that is not secured by collateral. Excludes proceeds from tax exempt unsecured debt. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 230 -SubTopic 10 -Section 45 -Paragraph 14 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=98514028&loc=d3e3255-108585 + Details
Name: | us-gaap_ProceedsFromIssuanceOfUnsecuredDebt
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_DebtInstrumentAxis=tdw_SeniorNotesDueTwentyTwentyFourMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=tdw_SeptemberTwoThousandThirteenSeniorUnsecuredNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MinimumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RangeAxis=us-gaap_MaximumMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=tdw_AugustTwoThousandElevenSeniorUnsecuredNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=tdw_SeptemberTwentyTenSeniorUnsecuredNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | dei_LegalEntityAxis=tdw_TromsOffshoreSupplyAsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=tdw_SeniorNotesDueInAprilTwentyTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=tdw_SeniorNotesDueInJanuaryTwentyTwentySevenMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DebtInstrumentAxis=tdw_SeniorNotesDueTwentyTwentySixMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RestructuringPlanAxis=tdw_PlanOfReorganizationMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_LongtermDebtTypeAxis=us-gaap_SeniorNotesMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |