XML 35 R79.htm IDEA: XBRL DOCUMENT
v3.19.3.a.u2

Schedule of Reconciliation of Unrecognized Tax Benefits (Detail) - USD ($) $ in Thousands | 4 Months Ended | 5 Months Ended | 12 Months Ended
--- | --- | --- | ---
Jul. 31, 2017 | Dec. 31, 2017 | Dec. 31, 2019 | Dec. 31, 2018
Schedule Of Unrecognized Tax Benefits [Line Items] |  |  |  |
Begining Balance | $ 400,818 | $ 402,868 | $ 399,292 | $ 404,571
Additions based on tax positions related to the current year | 2,050 | 170 | 14,741 |
Additions based on tax positions related to a prior year |  | 2,578 | 1,964 | 6,903
Settlement and lapse of statute of limitations |  | (1,045) | (1,897) | (2,953)
Reductions based on tax positions related to a prior year |  |  | (58) | (18,086)
Ending Balance | $ 402,868 | $ 404,571 | $ 414,042 | 399,292
GulfMark |  |  |  |
Schedule Of Unrecognized Tax Benefits [Line Items] |  |  |  |
Additions from GulfMark business combination |  |  |  | $ 8,857

X
- Definition Schedule of unrecognized tax benefits. + References No definition available. + Details
Name: | tdw_ScheduleOfUnrecognizedTaxBenefitsLineItems
Namespace Prefix: | tdw_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of unrecognized tax benefits. + References Reference 1: http://www.xbrl.org/2003/role/disclosureRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 45 -Paragraph 10B -URI http://asc.fasb.org/extlink&oid=116821951&loc=SL37586934-109318 Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefits
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | instant

X
- Definition Amount of decrease in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Definition Amount of increase in unrecognized tax benefits resulting from acquisitions. + References No definition available. + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions that have been or will be taken in current period tax return. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(2) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of increase in unrecognized tax benefits resulting from tax positions taken in prior period tax returns. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(1) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | credit
Period Type: | duration

X
- Definition Amount of decrease in unrecognized tax benefits resulting from lapses of applicable statutes of limitations. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 740 -SubTopic 10 -Section 50 -Paragraph 15A -Subparagraph (a)(4) -URI http://asc.fasb.org/extlink&oid=84230637&loc=SL6600010-109319 + Details
Name: | us-gaap_UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_BusinessAcquisitionAxis=tdw_GulfMarkOffshoreIncMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |