Consolidated debt as percentage of capitalization.

No definition available.

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Period Type:	duration

- Definition

Interest coverage ratio.

+ References

No definition available.

+ Details

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Namespace Prefix:	tdw_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Definition

Line of credit estimated fair market value.

+ References

No definition available.

+ Details

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Namespace Prefix:	tdw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Line of Credit Facility Expiration Dates

+ References

No definition available.

+ Details

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Namespace Prefix:	tdw_
Data Type:	xbrli:gYearMonthItemType
Balance Type:	na
Period Type:	duration

- Definition

Line of credit facility, revolving line of credit

+ References

No definition available.

+ Details

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Namespace Prefix:	tdw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Line of credit facility, term loan

+ References

No definition available.

+ Details

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Namespace Prefix:	tdw_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Percentage points added to the reference rate to compute the variable rate on the debt instrument.

+ References

No definition available.

+ Details

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- 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

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Data Type:	xbrli:stringItemType
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Period Type:	duration

- Definition

The carrying value as of the balance sheet date of the current and noncurrent portions of long-term obligations drawn from a line of credit, which is a bank's commitment to make loans up to a specific amount. Examples of items that might be included in the application of this element may consist of letters of credit, standby letters of credit, and revolving credit arrangements, under which borrowings can be made up to a maximum amount as of any point in time conditional on satisfaction of specified terms before, as of and after the date of drawdowns on the line. Includes short-term obligations that would normally be classified as current liabilities but for which (a) postbalance sheet date issuance of a long term obligation to refinance the short term obligation on a long term basis, or (b) the enterprise has entered into a financing agreement that clearly permits the enterprise to refinance the short-term obligation on a long term basis and the following conditions are met (1) the agreement does not expire within 1 year and is not cancelable by the lender except for violation of an objectively determinable provision, (2) no violation exists at the BS date, and (3) the lender has entered into the financing agreement is expected to be financially capable of honoring the agreement.

+ 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))
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: 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(16))
-URI http://asc.fasb.org/extlink&oid=6879938&loc=d3e572229-122910

Reference 3: 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

+ Details

Name:	us-gaap_LineOfCredit
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Period remaining on line of credit facility before it terminates, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

No definition available.

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:durationItemType
Balance Type:	na
Period Type:	duration

- Definition

Maximum borrowing capacity under the credit facility without consideration of any current restrictions on the amount that could be borrowed or the amounts currently outstanding under the facility.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The fee, expressed as a percentage of the line of credit facility, for available but unused credit capacity under the credit facility.

+ References

No definition available.

+ Details

Name:	us-gaap_LineOfCreditFacilityUnusedCapacityCommitmentFeePercentage
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	duration

- Details

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Balance Type:
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- Details

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Balance Type:
Period Type:

- Details

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Namespace Prefix:
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- Details

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Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=tdw_PrimeOrFederalFundsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_LineOfCreditFacilityAxis=tdw_TermLoanFacilityMember
Namespace Prefix:
Data Type:	na
Balance Type:
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- Details

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Indebtedness - Bank Loan Agreement - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	May 31, 2015	Mar. 31, 2017	Jun. 30, 2016	Mar. 31, 2016
Minimum
Debt [Line Items]
Commitment fees on the unused portion of credit facility		0.15%
Interest coverage ratio		300.00%	300.00%
Minimum \| Eurodollar Rates
Debt [Line Items]
Revolving credit rate		1.25%
Maximum
Debt [Line Items]
Consolidated debt to consolidated total capitalization, ratio		55.00%
Commitment fees on the unused portion of credit facility		0.30%
Maximum \| Eurodollar Rates
Debt [Line Items]
Revolving credit rate		2.00%
Current Bank Loan Agreement
Debt [Line Items]
Bank loan agreement expiration date	2019-06
Revolving credit facility	$ 900,000,000	$ 900,000,000
Credit facility term	5 years
Revolving line of credit	$ 600,000,000
Term loan	$ 300,000,000
Prime or Federal Funds \| Minimum
Debt [Line Items]
Revolving credit rate		0.25%
Prime or Federal Funds \| Maximum
Debt [Line Items]
Revolving credit rate		1.00%
Term Loan Facility
Debt [Line Items]
Outstanding borrowing		$ 300,000,000		$ 300,000,000
Estimated fair market value of the borrowing		168,000,000
Revolving Credit Agreement
Debt [Line Items]
Outstanding borrowing		600,000,000		$ 600,000,000
Estimated fair market value of the borrowing		$ 336,000,000