XML 102 R94.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Change in Plan Assets and Obligations (Detail) - USD ($) $ in Thousands | 3 Months Ended | 4 Months Ended | 5 Months Ended | 6 Months Ended | 9 Months Ended | 12 Months Ended
--- | --- | --- | --- | --- | --- | ---
Jun. 30, 2018 | Jun. 30, 2017 | Jul. 31, 2017 | Dec. 31, 2017 | Jun. 30, 2018 | Jun. 30, 2017 | Dec. 31, 2017 | Mar. 31, 2017 | Mar. 31, 2016
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  |  |  |  | $ 103,443 |  |  |  |
Benefit obligation at end of the period |  |  |  | $ 103,443 |  |  | $ 103,443 |  |
Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  | $ 97,941 | $ 97,941 |  |  |  | 97,941 |  |
Benefit obligation at end of the period |  |  |  |  |  |  |  | $ 97,941 |
Pension Plans, Defined Benefit |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Employer contributions | $ 0 | 0 |  |  | 0 | $ 0 | 0 | 3,000 | $ 0
Current liabilities |  |  |  | (10,731) |  |  | (10,731) |  |
Noncurrent liabilities |  |  |  | (35,252) |  |  | (35,252) |  |
Net amount recognized |  |  |  | (45,983) |  |  | (45,983) |  |
Pension Plans, Defined Benefit | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Actuarial (gain) loss |  |  | 748 |  |  |  |  | 1,785 |
Current liabilities |  |  | (1,791) |  |  |  |  | (1,791) |
Noncurrent liabilities |  |  | (41,642) |  |  |  |  | (39,087) |
Net amount recognized |  |  | (43,433) |  |  |  |  | (40,878) |
Pension Plans, Defined Benefit | Change in Benefit Obligations |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  |  |  | 101,490 | 103,443 |  |  |  |
Service cost |  |  |  | 546 |  |  |  |  |
Interest cost |  |  |  | 1,599 |  |  |  |  |
Plan curtailment |  |  |  | (432) |  |  |  |  |
Benefits paid |  |  |  | (2,059) |  |  |  |  |
Actuarial (gain) loss |  |  |  | 2,322 |  |  |  |  |
Foreign currency exchange rate changes |  |  |  | (23) |  |  |  |  |
Benefit obligation at end of the period |  |  | 101,490 | 103,443 |  |  | 103,443 |  |
Pension Plans, Defined Benefit | Change in Benefit Obligations | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  | 97,941 | 97,941 | 101,490 |  |  | 97,941 | 95,830 |
Service cost |  |  | 393 |  |  |  |  | 1,182 |
Interest cost |  |  | 1,313 |  |  |  |  | 3,814 |
Benefits paid |  |  | (1,610) |  |  |  |  | (4,895) |
Actuarial (gain) loss |  |  | 3,322 |  |  |  |  | 2,082 |
Foreign currency exchange rate changes |  |  | 131 |  |  |  |  | (72) |
Benefit obligation at end of the period |  |  | 101,490 |  |  |  |  | 97,941 | 95,830
Pension Plans, Defined Benefit | Change In Plan Assets |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Fair value of plan assets at beginning of the period |  |  |  | 58,148 | 57,536 |  |  |  |
Actual return |  |  |  | 1,182 |  |  |  |  |
Expected return |  |  |  | 32 |  |  |  |  |
Actuarial (gain) loss |  |  |  | 217 |  |  |  |  |
Administrative expenses |  |  |  | (15) |  |  |  |  |
Plan curtailment |  |  |  | (100) |  |  |  |  |
Employer contributions |  |  |  | 625 |  |  |  |  |
Benefits paid |  |  |  | (2,059) |  |  |  |  |
Foreign currency exchange rate changes |  |  |  | (60) |  |  |  |  |
Fair value of plan assets at end of the period |  |  | 58,148 | 57,536 |  |  | 57,536 |  |
Payroll tax unrecognized in benefit obligation at end of the period |  |  |  | 76 |  |  | 76 |  |
Unfunded status at end of the period |  |  |  | (45,983) |  |  | (45,983) |  |
Pension Plans, Defined Benefit | Change In Plan Assets | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Fair value of plan assets at beginning of the period |  | 57,146 | 57,146 | 58,148 |  |  | 57,146 | 57,174 |
Actual return |  |  | 2,138 |  |  |  |  | 577 |
Expected return |  |  | 16 |  |  |  |  | 51 |
Actuarial (gain) loss |  |  | 109 |  |  |  |  | 148 |
Administrative expenses |  |  | (7) |  |  |  |  | (27) |
Employer contributions |  |  | 435 |  |  |  |  | 4,465 |
Benefits paid |  |  | (1,610) |  |  |  |  | (4,895) |
Foreign currency exchange rate changes |  |  | 139 |  |  |  |  | (51) |
Fair value of plan assets at end of the period |  |  | 58,148 |  |  |  |  | 57,146 | 57,174
Payroll tax unrecognized in benefit obligation at end of the period |  |  | 91 |  |  |  |  | 83 |
Unfunded status at end of the period |  |  | (43,433) |  |  |  |  | (40,878) |
Other Pension Plans, Defined Benefit |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Current liabilities |  |  |  | (282) |  |  | (282) |  |
Noncurrent liabilities |  |  |  | (2,642) |  |  | (2,642) |  |
Net amount recognized |  |  |  | (2,924) |  |  | (2,924) |  |
Other Pension Plans, Defined Benefit | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Actuarial (gain) loss |  |  | (335) |  |  |  |  | (1,138) |
Current liabilities |  |  | (418) |  |  |  |  | (418) |
Noncurrent liabilities |  |  | (4,399) |  |  |  |  | (4,393) |
Net amount recognized |  |  | (4,817) |  |  |  |  | (4,811) |
Other Pension Plans, Defined Benefit | Change in Benefit Obligations |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  |  |  | 4,817 | $ 2,924 |  |  |  |
Service cost |  |  |  | 29 |  |  |  |  |
Interest cost |  |  |  | 75 |  |  |  |  |
Participant contributions |  |  |  | 65 |  |  |  |  |
Plan amendment |  |  |  | (1,861) |  |  |  |  |
Benefits paid |  |  |  | (526) |  |  |  |  |
Actuarial (gain) loss |  |  |  | 325 |  |  |  |  |
Benefit obligation at end of the period |  |  | 4,817 | 2,924 |  |  | 2,924 |  |
Other Pension Plans, Defined Benefit | Change in Benefit Obligations | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Benefit obligation at beginning of the period |  | $ 4,811 | 4,811 | 4,817 |  |  | 4,811 | 5,573 |
Service cost |  |  | 23 |  |  |  |  | 81 |
Interest cost |  |  | 64 |  |  |  |  | 201 |
Participant contributions |  |  | 58 |  |  |  |  | 411 |
Benefits paid |  |  | (346) |  |  |  |  | (1,170) |
Actuarial (gain) loss |  |  | 207 |  |  |  |  | (285) |
Benefit obligation at end of the period |  |  | 4,817 |  |  |  |  | 4,811 | $ 5,573
Other Pension Plans, Defined Benefit | Change In Plan Assets |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Employer contributions |  |  |  | 461 |  |  |  |  |
Participant contributions |  |  |  | 65 |  |  |  |  |
Benefits paid |  |  |  | (526) |  |  |  |  |
Unfunded status at end of the period |  |  |  | $ (2,924) |  |  | $ (2,924) |  |
Other Pension Plans, Defined Benefit | Change In Plan Assets | Predecessor |  |  |  |  |  |  |  |  |
Schedule Of Pension And Other Postretirement Benefits Changes In Benefit Obligation And Fair Value Of Plan Assets [Line Items] |  |  |  |  |  |  |  |  |
Employer contributions |  |  | 288 |  |  |  |  | 759 |
Participant contributions |  |  | 58 |  |  |  |  | 411 |
Benefits paid |  |  | (346) |  |  |  |  | (1,170) |
Unfunded status at end of the period |  |  | $ (4,817) |  |  |  |  | $ (4,811) |

X
- Definition Defined Benefit Plan Assets Curtailments + References No definition available. + Details
Name: | tdw_DefinedBenefitPlanAssetsCurtailments
Namespace Prefix: | tdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Defined Benefit Plan Fair Value Of Plan Assets Beginning Of Year + References No definition available. + Details
Name: | tdw_DefinedBenefitPlanFairValueOfPlanAssetsBeginningOfYear
Namespace Prefix: | tdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Defined benefit plan unfunded status of plan. + References No definition available. + Details
Name: | tdw_DefinedBenefitPlanUnfundedStatusOfPlan
Namespace Prefix: | tdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | instant

X
- Definition Payroll Tax Unrecognized In Benefit Obligation + References No definition available. + Details
Name: | tdw_PayrollTaxUnrecognizedInBenefitObligation
Namespace Prefix: | tdw_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Schedule of Pension and Other Postretirement Benefits Changes in Benefit Obligation and Fair Value of Plan Assets [Line Items] + References No definition available. + Details
Name: | tdw_ScheduleOfPensionAndOtherPostretirementBenefitsChangesInBenefitObligationAndFairValueOfPlanAssetsLineItems
Namespace Prefix: | tdw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of increase (decrease) in plan assets of defined benefit plan from actual return (loss) determined by change in fair value of plan assets adjusted for contributions, benefit payments, and other expenses. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 + Details
Name: | us-gaap_DefinedBenefitPlanActualReturnOnPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of gain (loss) from change in actuarial assumptions which (increases) decreases benefit obligation of defined benefit plan. Assumptions include, but are not limited to, interest, mortality, employee turnover, salary, and temporary deviation from substantive plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanActuarialGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of administration expense of defined benefit plan which decreases plan assets. Excludes plan administration expense paid by employer. + References No definition available. + Details
Name: | us-gaap_DefinedBenefitPlanAdministrationExpenses
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanBenefitObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of payment to participant of defined benefit plan which decreases benefit obligation. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(6) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964 + Details
Name: | us-gaap_DefinedBenefitPlanBenefitObligationBenefitsPaid
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of contributions received by defined benefit plan from participant which increase benefit obligation. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanBenefitObligationContributionsByPlanParticipant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of contribution received by defined benefit plan from employer which increases plan assets. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(iv)(01) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (d)(ii) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (b) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 Reference 5: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanContributionsByEmployer
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of (increase) decrease in benefit obligation of defined benefit plan from event reducing expected years of future service of present employees or eliminating accrual of benefits for some or all future services of present employees. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(10) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanCurtailments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of expected return (loss) recognized in net periodic benefit (cost) credit, calculated based on expected long-term rate of return and market-related value of plan assets of defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 2: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(3) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of foreign currency translation gain (loss) which (increases) decreases benefit obligation of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(5) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cost recognized for passage of time related to defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 + Details
Name: | us-gaap_DefinedBenefitPlanInterestCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase (decrease) in benefit obligation of defined benefit plan from change in terms of existing plan or initiation of new plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(7) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAmendments
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of payment to participant under defined benefit plan which decreases plan assets. For pension plan, payment includes, but is not limited to, pension benefits and death benefits. For other postretirement plan, payment includes, but is not limited to, prescription drug benefits, health care benefits, life insurance benefits, and legal, educational and advisory services. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 60 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=6414203&loc=d3e39716-114964 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(5) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsBenefitsPaid
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of contributions received by defined benefit plan from participant which increases plan assets. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(4) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsContributionsByPlanParticipant
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of foreign currency translation gain (loss) which increases (decreases) plan assets of defined benefit plan. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (b)(2) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of cost for actuarial present value of benefits attributed to service rendered by employee for defined benefit plan. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (h)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://www.xbrl.org/2003/role/exampleRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 55 -Paragraph 17 -URI http://asc.fasb.org/extlink&oid=112275985&loc=d3e4179-114921 Reference 3: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 6 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e2709-114920 Reference 4: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_DefinedBenefitPlanServiceCost
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as current. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(20)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1731-114919 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 942 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.9-03(15)) -URI http://asc.fasb.org/extlink&oid=6876686&loc=d3e534808-122878 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 944 -SubTopic 210 -Section S99 -Paragraph 1 -Subparagraph (SX 210.7-03(a)(15)) -URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 + Details
Name: | us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of liability, recognized in statement of financial position, for defined benefit pension and other postretirement plans, classified as noncurrent. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 50 -Paragraph 1 -Subparagraph (c) -URI http://asc.fasb.org/extlink&oid=108410482&loc=d3e1928-114920 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 2 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1703-114919 Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 715 -SubTopic 20 -Section 45 -Paragraph 3 -URI http://asc.fasb.org/extlink&oid=109237824&loc=d3e1731-114919 Reference 4: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 210 -SubTopic 10 -Section S99 -Paragraph 1 -Subparagraph (SX 210.5-02(24)) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Details
Name: | us-gaap_StatementScenarioAxis=us-gaap_PredecessorMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=us-gaap_PensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=tdw_ChangeInBenefitObligationsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_DefinedBenefitPlanByPlanAssetCategoriesAxis=tdw_ChangeInPlanAssetsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |

X
- Details
Name: | us-gaap_RetirementPlanNameAxis=us-gaap_OtherPensionPlansDefinedBenefitMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |