CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) $ in Thousands		4 Months Ended	5 Months Ended	12 Months Ended
		Jul. 31, 2017	Dec. 31, 2017	Dec. 31, 2018	Mar. 31, 2017
Revenues:
Total revenues			$ 178,753	$ 406,520
Costs and expenses:
Vessel operating costs			120,502	269,580
Costs of other operating revenues			3,792	5,530
General and administrative			46,619	110,023
Vessel operating leases			1,215
Depreciation and amortization			20,337	58,293
Gain on asset dispositions, net			(6,616)	(10,624)
Impairment of due from affiliate				20,083
Long-lived asset impairments	[1]		16,777	61,132
Total costs and expenses			202,626	514,017
Operating loss			(23,873)	(107,497)
Other income (expense):
Foreign exchange gain (loss)			(407)	106
Equity in net earnings (losses) of unconsolidated companies			2,130	(18,864)
Interest income and other, net			2,771	11,294
Reorganization items			(4,299)
Loss on early extinguishment of debt				(8,119)
Interest and other debt costs, net			(13,009)	(30,439)
Total other income (expenses)			(12,814)	(46,022)
Loss before income taxes			(36,687)	(153,519)
Income tax (benefit) expense			2,039	18,252
Net loss			(38,726)	(171,771)
Less: Net income (losses) attributable to noncontrolling interests			540	(254)
Net loss attributable to Tidewater Inc.			$ (39,266)	$ (171,517)
Basic loss per common share	[2]		$ (1.82)	$ (6.45)
Diluted loss per common share	[3]		$ (1.82)	$ (6.45)
Weighted average common shares outstanding	[4]		21,539,143	26,589,883
Adjusted weighted average common shares			21,539,143	26,589,883
Vessel Revenues
Revenues:
Total revenues			$ 171,884	$ 397,206
Other Operating Revenues
Revenues:
Total revenues			$ 6,869	$ 9,314
Predecessor
Revenues:
Total revenues		$ 151,369			$ 601,611
Costs and expenses:
Vessel operating costs		116,438			359,171
Costs of other operating revenues		2,348			12,729
General and administrative		41,832			145,879
Vessel operating leases		6,165			33,766
Depreciation and amortization		47,447			167,291
Gain on asset dispositions, net		(3,561)			(24,099)
Long-lived asset impairments	[1]	184,748			484,727
Total costs and expenses		395,417			1,179,464
Operating loss		(244,048)			(577,853)
Other income (expense):
Foreign exchange gain (loss)		(3,181)			(1,638)
Equity in net earnings (losses) of unconsolidated companies		4,786			5,710
Interest income and other, net		2,384			5,193
Reorganization items		(1,396,905)
Interest and other debt costs, net		(11,179)			(75,026)
Total other income (expenses)		(1,404,095)			(65,761)
Loss before income taxes		(1,648,143)			(643,614)
Income tax (benefit) expense		(1,234)			6,397
Net loss		(1,646,909)			(650,011)
Less: Net income (losses) attributable to noncontrolling interests					10,107
Net loss attributable to Tidewater Inc.		$ (1,646,909)			$ (660,118)
Basic loss per common share	[2]	$ (34.95)			$ (14.02)
Diluted loss per common share	[3]	$ (34.95)			$ (14.02)
Weighted average common shares outstanding	[4]	47,121,330			47,071,066
Adjusted weighted average common shares		47,121,330			47,071,066
Predecessor | Vessel Revenues
Revenues:
Total revenues		$ 146,597			$ 583,816
Predecessor | Other Operating Revenues
Revenues:
Total revenues		$ 4,772			$ 17,795

[1] The twelve months ended December 31, 2018, the period August 1, 2017 through December 31, 2017 and the twelve months ended March 31, 2017 included $3.5 million, $2.3 million and $2.2 million respectively, of impairments related to inventory and other non-vessel assets. There were no impairments to non-vessel assets during the period April 1, 2017 through July 31, 2017.

[2] We calculate “Loss per share, basic” by dividing “Net loss available to common shareholders” by “Weighted average outstanding share of common stock, basic”.

[3] We calculate “Loss per share, diluted” by dividing “Net loss available to common shareholders” by “Weighted average common stock and equivalents”.

[4] Basic weighted average shares outstanding included 2,547 and 924,125 shares issuable upon the exercise of New Creditor Warrants held by U.S. citizens at December 31, 2018 (Successor) and December 31, 2017 (Successor).