Comparison of Total Assets (Parenthetical) (Detail) (Corporate Vessels, USD $) In Millions, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Corporate Vessels
Segment Reporting Information [Line Items]
Construction costs	$ 222.8	$ 249.4

Significant Commitments Progress Payments Invested Not Yet Assigned To Marine Segments

No definition available.

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