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Number of Shares of Tidewater Common Stock Held by Plan (Detail) - shares | Mar. 31, 2017 | Mar. 31, 2016
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Defined Contribution Savings Plan 401k |  |
Defined Contribution Plan Disclosure [Line Items] |  |
Number of shares of Tidewater common stock held by 401(k) plan | 291,957 | 351,675

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- Definition Number of common stock held in a trust that has been set up specifically to accumulate stock for the sole purpose of distribution to participating employees but not yet earned. + References Reference 1: http://www.xbrl.org/2003/role/presentationRef -Publisher FASB -Name Accounting Standards Codification -Topic 718 -SubTopic 40 -Section 25 -Paragraph 12 -URI http://asc.fasb.org/extlink&oid=65888597&loc=d3e16701-113920 + Details
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Balance Type: | na
Period Type: | instant

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- 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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- Details
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