XML 164 R155.htm IDEA: XBRL DOCUMENT
v3.10.0.1

Valuation and Qualifying Accounts (Parenthetical) (Detail) $ in Millions | 4 Months Ended
--- | ---
Jul. 31, 2017 USD ($)
Fresh-start Accounting Adjustments |
Valuation and Qualifying Accounts Disclosure [Line Items] |
Deductions from allowance for doubtful accounts | $ 15.4

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: | srt_ValuationAndQualifyingAccountsDisclosureLineItems
Namespace Prefix: | srt_
Data Type: | xbrli:stringItemType
Balance Type: | na
Period Type: | duration

X
- Definition Amount of direct write-downs of accounts receivable charged against the allowance. + References Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef -Publisher FASB -Name Accounting Standards Codification -Topic 310 -SubTopic 10 -Section 50 -Paragraph 4 -URI http://asc.fasb.org/extlink&oid=84173941&loc=d3e5074-111524 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 210.5-02.4) -URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682 + Details
Name: | us-gaap_AllowanceForDoubtfulAccountsReceivableWriteOffs
Namespace Prefix: | us-gaap_
Data Type: | xbrli:monetaryItemType
Balance Type: | debit
Period Type: | duration

X
- Details
Name: | us-gaap_FreshStartAdjustmentsTypeOfFreshStartAdjustmentAxis=tdw_FreshStartAccountingAdjustmentsMember
Namespace Prefix: |
Data Type: | na
Balance Type: |
Period Type: |