Reclassifications from Accumulated Other Comprehensive Income (Loss) to Condensed Consolidated Statement of Income (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2015	Dec. 31, 2014
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income and other, net	$ 609	$ 434	$ 1,754	$ 1,555
Interest and other debt costs	13,312	12,239	39,741	37,927
Loss before income taxes	(24,282)	(221,051)	(61,770)	(81,668)
Tax effect	(4,679)	(60,070)	16,996	(25,211)
Net loss attributable to Tidewater Inc.	(19,509)	(160,694)	(78,396)	(56,114)
Reclassification out of Accumulated Other Comprehensive Income
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Loss before income taxes	240	207	984	775
Tax effect	84	72	344	271
Net loss attributable to Tidewater Inc.	156	135	640	504
Reclassification out of Accumulated Other Comprehensive Income | Available for Sale Securities
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest income and other, net	(37)	29	155	238
Reclassification out of Accumulated Other Comprehensive Income | Interest Rate Swaps
Reclassification Adjustment out of Accumulated Other Comprehensive Income [Line Items]
Interest and other debt costs	$ 277	$ 178	$ 829	$ 537