$TDW
TIDEWATER INC Stock $tdw

$tdw Overview Financials Valuation SEC Filings Company Website

2020 Q4 Form 10-K Financial Statement

#000143774921005037 Filed on March 04, 2021

Income Statement

Concept	2020 Q4	2020	2019 Q4
Revenue	$91.90M	$397.0M	$118.8M
YoY Change	-22.63%	-18.4%	7.75%
Cost Of Revenue	$63.70M	$272.2M	$86.90M
YoY Change	-26.7%	-18.01%
Gross Profit	$28.10M	-$29.67M	$31.90M
YoY Change	-11.91%	-530.37%	-71.06%
Gross Profit Margin	30.58%	-7.47%	26.86%
Selling, General & Admin	$11.00M	$66.10M	$21.50M
YoY Change	-48.84%	-31.79%	-37.32%
% of Gross Profit	39.15%		67.4%
Research & Development
YoY Change
% of Gross Profit
Depreciation & Amortization	$19.40M	$73.03M	$19.40M
YoY Change	0.0%	-5.21%	11.49%
% of Gross Profit	69.04%		60.82%
Operating Expenses	$41.70M	$182.8M	$49.70M
YoY Change	-16.1%	-8.09%	-8.64%
Operating Profit	-$13.60M	-$186.8M	-$50.04M
YoY Change	-72.82%	115.7%	-28.59%
Interest Expense	-$8.600M	$1.228M	-$9.300M
YoY Change	-7.53%	-81.39%	116.28%
% of Operating Profit
Other Income/Expense, Net		-$10.86M
YoY Change		-59.62%
Pretax Income	-$33.90M	-$197.7M	-$59.30M
YoY Change	-42.83%	74.16%	-28.12%
Income Tax	-$4.500M	-$965.0K	$1.300M
% Of Pretax Income
Net Earnings	-$29.20M	-$196.2M	-$59.85M
YoY Change	-51.21%	38.45%	-33.87%
Net Earnings / Revenue	-31.77%	-49.43%	-50.39%
Basic Earnings Per Share		-$4.86	-$1.52
Diluted Earnings Per Share	-$719.2K	-$4.86	-$1.52
COMMON SHARES
Basic Shares Outstanding	40.55M	40.35M	39.23M
Diluted Shares Outstanding		40.35M

Balance Sheet

Concept	2020 Q4	2020	2019 Q4
SHORT-TERM ASSETS
Cash & Short-Term Investments	$149.9M	$149.9M	$218.3M
YoY Change	-31.33%	-31.33%	-41.29%
Cash & Equivalents	$149.9M	$149.9M	$218.3M
Short-Term Investments
Other Short-Term Assets	$48.20M	$48.20M	$61.00M
YoY Change	-20.98%	-20.98%	415.38%
Inventory	$15.90M	$15.90M	$21.90M
Prepaid Expenses
Receivables	$112.6M	$112.6M	$110.2M
Other Receivables	$62.10M	$62.10M	$126.0M
Total Short-Term Assets	$388.6M	$388.6M	$537.3M
YoY Change	-27.67%	-27.68%	-21.37%
LONG-TERM ASSETS
Property, Plant & Equipment	$780.3M	$783.7M	$780.3M
YoY Change	0.0%	-16.92%	-28.4%
Goodwill
YoY Change
Intangibles
YoY Change
Long-Term Investments	$0.00		$0.00
YoY Change			-100.0%
Other Assets	$25.74M	$78.80M	$36.34M
YoY Change	-29.15%	-20.32%	15.99%
Total Long-Term Assets	$862.5M	$862.6M	$1.042B
YoY Change	-17.24%	-17.23%	-8.93%
TOTAL ASSETS
Total Short-Term Assets	$388.6M	$388.6M	$537.3M
Total Long-Term Assets	$862.5M	$862.6M	$1.042B
Total Assets	$1.251B	$1.251B	$1.580B
YoY Change	-20.79%	-20.79%	-13.58%
SHORT-TERM LIABILITIES
YoY Change
Accounts Payable	$16.98M	$17.00M	$27.50M
YoY Change	-38.25%	-38.18%	-13.9%
Accrued Expenses	$52.42M	$53.60M	$74.00M
YoY Change	-29.16%	-28.05%	19.77%
Deferred Revenue
YoY Change
Short-Term Debt	$0.00	$0.00	$0.00
YoY Change
Long-Term Debt Due	$27.80M	$27.80M	$9.890M
YoY Change	181.06%	180.81%	15.43%
Total Short-Term Liabilities	$183.2M	$183.2M	$185.7M
YoY Change	-1.35%	-1.35%	17.25%
LONG-TERM LIABILITIES
Long-Term Debt	$164.9M	$164.9M	$279.0M
YoY Change	-40.89%	-40.9%	-35.17%
Other Long-Term Liabilities	$79.79M	$79.80M	$98.40M
YoY Change	-18.91%	-16.7%	4.65%
Total Long-Term Liabilities	$244.7M	$244.7M	$377.4M
YoY Change	-35.16%	-34.71%	-28.03%
TOTAL LIABILITIES
Total Short-Term Liabilities	$183.2M	$183.2M	$185.7M
Total Long-Term Liabilities	$244.7M	$244.7M	$377.4M
Total Liabilities	$427.9M	$429.1M	$563.1M
YoY Change	-24.01%	-24.01%	-17.53%
SHAREHOLDERS EQUITY
Retained Earnings	-$548.9M		-$352.5M
YoY Change	55.71%		67.25%
Common Stock	$1.372B		$1.368B
YoY Change	0.31%		1.12%
Preferred Stock
YoY Change
Treasury Stock (at cost)
YoY Change
Treasury Stock Shares
Shareholders Equity	$822.1M	$822.1M	$1.015B
YoY Change
Total Liabilities & Shareholders Equity	$1.251B	$1.251B	$1.580B
YoY Change	-20.79%	-20.79%	-13.58%

Cashflow Statement

Concept	2020 Q4	2020	2019 Q4
OPERATING ACTIVITIES
Net Income	-$29.20M	-$196.2M	-$59.85M
YoY Change	-51.21%	38.45%	-33.87%
Depreciation, Depletion And Amortization	$19.40M	$73.03M	$19.40M
YoY Change	0.0%	-5.21%	11.49%
Cash From Operating Activities	$2.200M	$3.986M	$5.300M
YoY Change	-58.49%	-112.68%	-128.96%
INVESTING ACTIVITIES
Capital Expenditures	-$10.20M	$14.90M	-$4.100M
YoY Change	148.78%	-17.21%	-66.67%
Acquisitions		$0.00
YoY Change
Other Investing Activities	$6.800M	$38.30M	$3.700M
YoY Change	83.78%	32.99%	-94.96%
Cash From Investing Activities	-$3.400M	$23.40M	-$400.0K
YoY Change	750.0%	115.65%	-100.65%
FINANCING ACTIVITIES
Cash Dividend Paid
YoY Change
Common Stock Issuance & Retirement, Net		$0.00
YoY Change
Debt Paid & Issued, Net
YoY Change
Cash From Financing Activities	-65.60M	-$99.77M	-140.0M
YoY Change	-53.14%	-33.3%	23.13%
NET CHANGE
Cash From Operating Activities	2.200M	$3.986M	5.300M
Cash From Investing Activities	-3.400M	$23.40M	-400.0K
Cash From Financing Activities	-65.60M	-$99.77M	-140.0M
Net Change In Cash	-66.80M	-$72.38M	-135.1M
YoY Change	-50.56%	-57.46%	90.55%
FREE CASH FLOW
Cash From Operating Activities	$2.200M	$3.986M	$5.300M
Capital Expenditures	-$10.20M	$14.90M	-$4.100M
Free Cash Flow	$12.40M	-$10.91M	$9.400M
YoY Change	31.91%	-77.92%	-256.67%

Facts In Submission

Frame	Concept Type	Concept / XBRL Key	Value	Unit
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CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesTax	0	USD
CY2020	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2019	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2018	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2020	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2019	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2018	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentTaxPeriodIncreaseDecrease	0	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0	USD
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
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CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	125000000
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CY2020Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	40704984
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	39941327
CY2019Q4	us-gaap	Common Stock Shares Outstanding CommonStockSharesOutstanding	39941327
CY2019	us-gaap	Dividends Common Stock Cash DividendsCommonStockCash	0	USD
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CY2020Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2019Q4	us-gaap	Commitments And Contingencies CommitmentsAndContingencies		USD
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansTax	0	USD
CY2020	tdw	Highly Liquid Investments Maturity Period HighlyLiquidInvestmentsMaturityPeriod	P3Y
CY2020	tdw	Inspection Interval InspectionInterval	5
CY2020	tdw	Number Of Vessels Transfer From Held For Sale To Active Fleet NumberOfVesselsTransferFromHeldForSaleToActiveFleet	2	pure
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CY2020	us-gaap	Net Income Loss NetIncomeLoss	-196242000	USD
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CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-4.86
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-3.71
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-6.45
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-4.86
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-3.71
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-6.45
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	40354638
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	38204934
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26589883
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	40354638
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	38204934
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26589883
CY2020	us-gaap	Profit Loss ProfitLoss	-196696000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	-141219000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	-171771000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Available For Sale Securities Adjustment Net Of Tax OtherComprehensiveIncomeLossAvailableForSaleSecuritiesAdjustmentNetOfTax	-256000	USD
CY2020	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	-2309000	USD
CY2019	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	-2121000	USD
CY2018	tdw	Other Comprehensive Income Supplemental Executive Retirement Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomeSupplementalExecutiveRetirementPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	2214000	USD
CY2020	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	1741000	USD
CY2019	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	-309000	USD
CY2018	tdw	Other Comprehensive Income Pension Plan Minimum Liability Adjustment Net Of Tax Period Increase Decrease OtherComprehensiveIncomePensionPlanMinimumLiabilityAdjustmentNetOfTaxPeriodIncreaseDecrease	1919000	USD
CY2020	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-0	USD
CY2019	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	-0	USD
CY2018	us-gaap	Other Comprehensive Income Loss Pension And Other Postretirement Benefit Plans Adjustment Net Of Tax OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax	1536000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-197264000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-143649000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-169430000	USD
CY2017Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1021944000	USD
CY2018	us-gaap	Comprehensive Income Net Of Tax Including Portion Attributable To Noncontrolling Interest ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest	-169430000	USD
CY2018	tdw	Stock Issued During Period Value Warrant Exercises StockIssuedDuringPeriodValueWarrantExercises	3000	USD
CY2018	tdw	Stock Issued During Period Value Amortization Or Cancellation Of Restricted Stock StockIssuedDuringPeriodValueAmortizationOrCancellationOfRestrictedStock	8914000	USD
CY2018	us-gaap	Minority Interest Decrease From Distributions To Noncontrolling Interest Holders MinorityInterestDecreaseFromDistributionsToNoncontrollingInterestHolders	2000000	USD
CY2018Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1144923000	USD
CY2019	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-143649000	USD
CY2019	tdw	Stock Issued During Period Value Warrant Exercises StockIssuedDuringPeriodValueWarrantExercises	0	USD
CY2019	tdw	Stock Issued During Period Value Amortization Or Cancellation Of Restricted Stock StockIssuedDuringPeriodValueAmortizationOrCancellationOfRestrictedStock	15136000	USD
CY2019Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	1016410000	USD
CY2020	us-gaap	Comprehensive Income Net Of Tax ComprehensiveIncomeNetOfTax	-197264000	USD
CY2020	tdw	Stock Issued During Period Value Warrant Exercises StockIssuedDuringPeriodValueWarrantExercises	0	USD
CY2020	tdw	Stock Issued During Period Value Amortization Or Cancellation Of Restricted Stock StockIssuedDuringPeriodValueAmortizationOrCancellationOfRestrictedStock	4289000	USD
CY2020Q4	us-gaap	Stockholders Equity Including Portion Attributable To Noncontrolling Interest StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest	823272000	USD
CY2020	us-gaap	Profit Loss ProfitLoss	-196696000	USD
CY2019	us-gaap	Profit Loss ProfitLoss	-141219000	USD
CY2018	us-gaap	Profit Loss ProfitLoss	-171771000	USD
CY2020	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	73030000	USD
CY2019	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	77045000	USD
CY2018	us-gaap	Depreciation Depletion And Amortization DepreciationDepletionAndAmortization	51332000	USD
CY2020	tdw	Amortization Of Dry Docking And Survey Costs AmortizationOfDryDockingAndSurveyCosts	43679000	USD
CY2019	tdw	Amortization Of Dry Docking And Survey Costs AmortizationOfDryDockingAndSurveyCosts	24886000	USD
CY2018	tdw	Amortization Of Dry Docking And Survey Costs AmortizationOfDryDockingAndSurveyCosts	6961000	USD
CY2020	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	3961000	USD
CY2019	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	-4877000	USD
CY2018	us-gaap	Amortization Of Debt Discount Premium AmortizationOfDebtDiscountPremium	-1856000	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1224000	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	672000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	572000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	7591000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	2263000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets GainLossOnDispositionOfAssets	10624000	USD
CY2020	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	0	USD
CY2019	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	0	USD
CY2018	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	20083000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	52981000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	0	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	0	USD
CY2020	tdw	Increase Decrease In Accrued Property And Liability Losses IncreaseDecreaseInAccruedPropertyAndLiabilityLosses	2000000	USD
CY2019	tdw	Increase Decrease In Accrued Property And Liability Losses IncreaseDecreaseInAccruedPropertyAndLiabilityLosses	0	USD
CY2018	tdw	Increase Decrease In Accrued Property And Liability Losses IncreaseDecreaseInAccruedPropertyAndLiabilityLosses	0	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	74109000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	37773000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	61132000	USD
CY2020	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-0	USD
CY2019	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-0	USD
CY2018	us-gaap	Gains Losses On Extinguishment Of Debt GainsLossesOnExtinguishmentOfDebt	-8119000	USD
CY2020	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-0	USD
CY2019	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-1039000	USD
CY2018	us-gaap	Income Loss From Equity Method Investments Net Of Dividends Or Distributions IncomeLossFromEquityMethodInvestmentsNetOfDividendsOrDistributions	-28177000	USD
CY2020	us-gaap	Share Based Compensation ShareBasedCompensation	5117000	USD
CY2019	us-gaap	Share Based Compensation ShareBasedCompensation	19603000	USD
CY2018	us-gaap	Share Based Compensation ShareBasedCompensation	13406000	USD
CY2020	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	2606000	USD
CY2019	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	-1086000	USD
CY2018	us-gaap	Increase Decrease In Accounts And Other Receivables IncreaseDecreaseInAccountsAndOtherReceivables	-9088000	USD
CY2020	us-gaap	Increase Decrease In Due To Affiliates IncreaseDecreaseInDueToAffiliates	11949000	USD
CY2020	tdw	Premiums Paid On Redemption Of Secured Notes PremiumsPaidOnRedemptionOfSecuredNotes	-0	USD
CY2019	us-gaap	Increase Decrease In Due To Affiliates IncreaseDecreaseInDueToAffiliates	22193000	USD
CY2018	us-gaap	Increase Decrease In Due To Affiliates IncreaseDecreaseInDueToAffiliates	28644000	USD
CY2020	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-2588000	USD
CY2019	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	-2425000	USD
CY2018	us-gaap	Increase Decrease In Inventories IncreaseDecreaseInInventories	1955000	USD
CY2020	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-4264000	USD
CY2019	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	4120000	USD
CY2018	us-gaap	Increase Decrease In Other Current Assets IncreaseDecreaseInOtherCurrentAssets	-10893000	USD
CY2020	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-10520000	USD
CY2019	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-4438000	USD
CY2018	us-gaap	Increase Decrease In Accounts Payable Trade IncreaseDecreaseInAccountsPayableTrade	-15174000	USD
CY2020	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-17551000	USD
CY2019	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	8189000	USD
CY2018	us-gaap	Increase Decrease In Accrued Liabilities IncreaseDecreaseInAccruedLiabilities	-13348000	USD
CY2020	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	8685000	USD
CY2019	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	3008000	USD
CY2018	us-gaap	Increase Decrease In Other Current Liabilities IncreaseDecreaseInOtherCurrentLiabilities	1332000	USD
CY2020	tdw	Increase Decrease In Other Operating Liabilities And Deferred Credits IncreaseDecreaseInOtherOperatingLiabilitiesAndDeferredCredits	-20002000	USD
CY2019	tdw	Increase Decrease In Other Operating Liabilities And Deferred Credits IncreaseDecreaseInOtherOperatingLiabilitiesAndDeferredCredits	1270000	USD
CY2018	tdw	Increase Decrease In Other Operating Liabilities And Deferred Credits IncreaseDecreaseInOtherOperatingLiabilitiesAndDeferredCredits	-2023000	USD
CY2020	tdw	Increase Decrease In Cash Paid For Deferred Drydocking And Survey Costs IncreaseDecreaseInCashPaidForDeferredDrydockingAndSurveyCosts	33271000	USD
CY2019	tdw	Increase Decrease In Cash Paid For Deferred Drydocking And Survey Costs IncreaseDecreaseInCashPaidForDeferredDrydockingAndSurveyCosts	70437000	USD
CY2018	tdw	Increase Decrease In Cash Paid For Deferred Drydocking And Survey Costs IncreaseDecreaseInCashPaidForDeferredDrydockingAndSurveyCosts	25968000	USD
CY2020	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-8636000	USD
CY2019	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	3258000	USD
CY2018	us-gaap	Increase Decrease In Other Operating Capital Net IncreaseDecreaseInOtherOperatingCapitalNet	-6921000	USD
CY2020	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	3986000	USD
CY2019	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	-31423000	USD
CY2018	us-gaap	Net Cash Provided By Used In Operating Activities NetCashProvidedByUsedInOperatingActivities	3941000	USD
CY2020	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	38296000	USD
CY2019	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	28847000	USD
CY2018	us-gaap	Proceeds From Sale Of Productive Assets ProceedsFromSaleOfProductiveAssets	46115000	USD
CY2020	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	14900000	USD
CY2019	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	17998000	USD
CY2018	us-gaap	Payments To Acquire Property Plant And Equipment PaymentsToAcquirePropertyPlantAndEquipment	21391000	USD
CY2020	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2019	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	0	USD
CY2018	us-gaap	Cash Acquired From Acquisition CashAcquiredFromAcquisition	43806000	USD
CY2020	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	23396000	USD
CY2019	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	10849000	USD
CY2018	us-gaap	Net Cash Provided By Used In Investing Activities NetCashProvidedByUsedInInvestingActivities	68530000	USD
CY2020	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	98080000	USD
CY2019	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	133693000	USD
CY2018	us-gaap	Repayments Of Secured Debt RepaymentsOfSecuredDebt	105169000	USD
CY2019	tdw	Premiums Paid On Redemption Of Secured Notes PremiumsPaidOnRedemptionOfSecuredNotes	11402000	USD
CY2018	tdw	Premiums Paid On Redemption Of Secured Notes PremiumsPaidOnRedemptionOfSecuredNotes	-0	USD
CY2020	us-gaap	Repayments Of Unsecured Debt RepaymentsOfUnsecuredDebt	-0	USD
CY2019	us-gaap	Repayments Of Unsecured Debt RepaymentsOfUnsecuredDebt	-0	USD
CY2018	us-gaap	Repayments Of Unsecured Debt RepaymentsOfUnsecuredDebt	8377000	USD
CY2020	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	-0	USD
CY2019	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	-0	USD
CY2018	us-gaap	Payments Of Debt Extinguishment Costs PaymentsOfDebtExtinguishmentCosts	8119000	USD
CY2020	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2019	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	0	USD
CY2018	us-gaap	Proceeds From Issuance Of Common Stock ProceedsFromIssuanceOfCommonStock	3000	USD
CY2020	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	828000	USD
CY2019	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	4467000	USD
CY2018	us-gaap	Payments Related To Tax Withholding For Share Based Compensation PaymentsRelatedToTaxWithholdingForShareBasedCompensation	4400000	USD
CY2020	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-857000	USD
CY2019	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	0	USD
CY2018	us-gaap	Proceeds From Payments For Other Financing Activities ProceedsFromPaymentsForOtherFinancingActivities	-2000000	USD
CY2020	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-99765000	USD
CY2019	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-149562000	USD
CY2018	us-gaap	Net Cash Provided By Used In Financing Activities NetCashProvidedByUsedInFinancingActivities	-128062000	USD
CY2020	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-72383000	USD
CY2019	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-170136000	USD
CY2018	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Period Increase Decrease Including Exchange Rate Effect CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseIncludingExchangeRateEffect	-55591000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	227608000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	397744000	USD
CY2017Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	453335000	USD
CY2020Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	155225000	USD
CY2019Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	227608000	USD
CY2018Q4	us-gaap	Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents Including Disposal Group And Discontinued Operations CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsIncludingDisposalGroupAndDiscontinuedOperations	397744000	USD
CY2020	us-gaap	Interest Paid Net InterestPaidNet	21235000	USD
CY2019	us-gaap	Interest Paid Net InterestPaidNet	32687000	USD
CY2018	us-gaap	Interest Paid Net InterestPaidNet	32326000	USD
CY2020	us-gaap	Income Taxes Paid IncomeTaxesPaid	13018000	USD
CY2019	us-gaap	Income Taxes Paid IncomeTaxesPaid	14378000	USD
CY2018	us-gaap	Income Taxes Paid IncomeTaxesPaid	16828000	USD
CY2020	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	0	USD
CY2019	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	0	USD
CY2018	us-gaap	Noncash Or Part Noncash Acquisition Value Of Assets Acquired1 NoncashOrPartNoncashAcquisitionValueOfAssetsAcquired1	285492000	USD
CY2020	us-gaap	Stock Issued1 StockIssued1	0	USD
CY2019	us-gaap	Stock Issued1 StockIssued1	0	USD
CY2018	us-gaap	Stock Issued1 StockIssued1	285492000	USD
CY2020	us-gaap	Use Of Estimates UseOfEstimates	<p style="font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:left;"><b>Use of Estimates in Preparation of Financial Statements </b></p> <p style="font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:left;"> </p> <p style="font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:justify;">The preparation of financial statements in conformity with accounting principles generally accepted in the United States of America requires management to make estimates and assumptions that affect the reported amounts of assets and liabilities and disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the recorded amounts of revenues and expenses during the reporting period. The accompanying consolidated financial statements include estimates for allowance for credit losses, useful lives of property and equipment, income tax provisions, impairments, commitments and contingencies and certain accrued liabilities. We evaluate our estimates and assumptions on an ongoing basis based on a combination of historical information and various other assumptions that are considered reasonable under the particular circumstances, the results of which form the basis for making judgments about carrying values of assets and liabilities that are <em style="font: inherit;">not</em> readily apparent from other sources. These accounting policies involve judgment and uncertainties to such an extent that there is reasonable likelihood that materially different amounts could have been reported under different conditions or if different assumptions had been used and, as such, actual results <em style="font: inherit;"> may </em>differ from these estimates.</p> <p style="font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:justify;"> </p>
CY2020	tdw	Increase Of Amortization Period IncreaseOfAmortizationPeriod	P30M
CY2020Q4	us-gaap	Machinery And Equipment Gross MachineryAndEquipmentGross	940175000	USD
CY2019Q4	us-gaap	Machinery And Equipment Gross MachineryAndEquipmentGross	1051558000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	16861000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Other PropertyPlantAndEquipmentOther	13119000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	957036000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Gross PropertyPlantAndEquipmentGross	1064677000	USD
CY2020Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	176718000	USD
CY2019Q4	us-gaap	Accumulated Depreciation Depletion And Amortization Property Plant And Equipment AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment	125716000	USD
CY2020Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	780318000	USD
CY2019Q4	us-gaap	Property Plant And Equipment Net PropertyPlantAndEquipmentNet	938961000	USD
CY2020	tdw	Number Of Offshore Supply Vessels NumberOfOffshoreSupplyVessels	172	pure
CY2020	tdw	Number Of Vessels Disposed NumberOfVesselsDisposed	23	pure
CY2020	tdw	Number Of Assets Held For Sale NumberOfAssetsHeldForSale	23	pure
CY2019	tdw	Number Of Offshore Supply Vessels NumberOfOffshoreSupplyVessels	217	pure
CY2019	tdw	Number Of Vessels Disposed NumberOfVesselsDisposed	46	pure
CY2020	us-gaap	Net Income Loss NetIncomeLoss	-196242000	USD
CY2019	us-gaap	Net Income Loss NetIncomeLoss	-141743000	USD
CY2018	us-gaap	Net Income Loss NetIncomeLoss	-171517000	USD
CY2020	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	40354638
CY2019	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	38204934
CY2018	us-gaap	Weighted Average Number Of Shares Outstanding Basic WeightedAverageNumberOfSharesOutstandingBasic	26589883
CY2020	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2019	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2018	us-gaap	Incremental Common Shares Attributable To Share Based Payment Arrangements IncrementalCommonSharesAttributableToShareBasedPaymentArrangements	0
CY2020	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	40354638
CY2019	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	38204934
CY2018	us-gaap	Weighted Average Number Of Diluted Shares Outstanding WeightedAverageNumberOfDilutedSharesOutstanding	26589883
CY2020	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-4.86
CY2019	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-3.71
CY2018	us-gaap	Earnings Per Share Basic EarningsPerShareBasic	-6.45
CY2020	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-4.86
CY2019	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-3.71
CY2018	us-gaap	Earnings Per Share Diluted EarningsPerShareDiluted	-6.45
CY2020	us-gaap	Concentration Risk Credit Risk ConcentrationRiskCreditRisk	<p style="font-family:'Times New Roman', Times, serif;font-size:10pt;margin:0pt;text-align:left;"><b>Concentrations of Credit Risk </b></p> <p style="font-family: 'Times New Roman', Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;"> </p> <p style="font-family: "Times New Roman", Times, serif; font-size: 10pt; margin: 0pt; text-align: justify;">Our financial instruments that are exposed to concentrations of credit risk consist primarily of trade and other receivables from a variety of domestic, international and national energy companies. We manage our exposure to risk by performing ongoing credit evaluations of our customers’ financial condition and <em style="font: inherit;"> may </em>at times require prepayments or other forms of collateral. We also have net receivable balances related to joint ventures in which we own less than <em style="font: inherit;">50%.</em> We review and evaluate these receivables for collectability in a similar manner as we evaluate trade receivables. We maintain an allowance for credit loss based on expected collectability and do <em style="font: inherit;">not</em> believe we are generally exposed to concentrations of credit risk that are likely to have a material adverse impact on our financial position, results of operations, or cash flows.</p> <p style="font-family: 'Times New Roman', Times, serif; font-size: 10pt; margin-top: 0pt; margin-bottom: 0pt;"> </p>
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets	77942000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Property Plant And Equipment BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPropertyPlantAndEquipment	360701000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Other Noncurrent Assets BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedOtherNoncurrentAssets	779000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Liabilities BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities	33881000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Long Term Debt BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt	100000000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Other BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesOther	20049000	USD
CY2020Q4	us-gaap	Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNet	285492000	USD
CY2018	us-gaap	Business Acquisitions Pro Forma Revenue BusinessAcquisitionsProFormaRevenue	500118000000	USD
CY2018	us-gaap	Business Acquisitions Pro Forma Net Income Loss BusinessAcquisitionsProFormaNetIncomeLoss	-196057000000	USD
CY2018	us-gaap	Business Acquisition Pro Forma Earnings Per Share Basic BusinessAcquisitionProFormaEarningsPerShareBasic	-5.66
CY2018	us-gaap	Business Acquisition Pro Forma Earnings Per Share Diluted BusinessAcquisitionProFormaEarningsPerShareDiluted	-5.66
CY2020Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	197975000	USD
CY2019Q4	us-gaap	Debt Instrument Carrying Amount DebtInstrumentCarryingAmount	297659000	USD
CY2020Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	5244000	USD
CY2019Q4	us-gaap	Debt Instrument Unamortized Discount Premium Net DebtInstrumentUnamortizedDiscountPremiumNet	8725000	USD
CY2020Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	27797000	USD
CY2019Q4	us-gaap	Long Term Debt Current LongTermDebtCurrent	9890000	USD
CY2020Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	164934000	USD
CY2019Q4	us-gaap	Long Term Debt Noncurrent LongTermDebtNoncurrent	279044000	USD
CY2020Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	2100000	USD
CY2019Q4	us-gaap	Restricted Cash Current RestrictedCashCurrent	5800000	USD
CY2020	us-gaap	Interest And Debt Expense InterestAndDebtExpense	24156000	USD
CY2019	us-gaap	Interest And Debt Expense InterestAndDebtExpense	29068000	USD
CY2018	us-gaap	Interest And Debt Expense InterestAndDebtExpense	30439000	USD
CY2020	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	0	USD
CY2019	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	0	USD
CY2018	us-gaap	Interest Costs Capitalized InterestCostsCapitalized	521000	USD
CY2020	us-gaap	Interest Costs Incurred InterestCostsIncurred	24156000	USD
CY2019	us-gaap	Interest Costs Incurred InterestCostsIncurred	29068000	USD
CY2018	us-gaap	Interest Costs Incurred InterestCostsIncurred	30960000	USD
CY2020Q4	us-gaap	Due From Related Parties Current DueFromRelatedPartiesCurrent	62050000	USD
CY2019Q4	us-gaap	Due From Related Parties Current DueFromRelatedPartiesCurrent	125972000	USD
CY2020Q4	us-gaap	Due To Related Parties Current DueToRelatedPartiesCurrent	53194000	USD
CY2019Q4	us-gaap	Due To Related Parties Current DueToRelatedPartiesCurrent	50186000	USD
CY2020Q4	us-gaap	Related Party Transaction Due From To Related Party Current RelatedPartyTransactionDueFromToRelatedPartyCurrent	8856000	USD
CY2019Q4	us-gaap	Related Party Transaction Due From To Related Party Current RelatedPartyTransactionDueFromToRelatedPartyCurrent	75786000	USD
CY2019Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	31475000	USD
CY2018Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	29347000	USD
CY2017Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	99448000	USD
CY2020	tdw	Due To Affiliate Commisions To Be Paid DueToAffiliateCommisionsToBePaid	4152000	USD
CY2019	tdw	Due To Affiliate Commisions To Be Paid DueToAffiliateCommisionsToBePaid	4937000	USD
CY2018	tdw	Due To Affiliate Commisions To Be Paid DueToAffiliateCommisionsToBePaid	5502000	USD
CY2020	tdw	Due To Affiliate Amounts Paid By Affiliate DueToAffiliateAmountsPaidByAffiliate	9037000	USD
CY2019	tdw	Due To Affiliate Amounts Paid By Affiliate DueToAffiliateAmountsPaidByAffiliate	9654000	USD
CY2018	tdw	Due To Affiliate Amounts Paid By Affiliate DueToAffiliateAmountsPaidByAffiliate	14778000	USD
CY2020	tdw	Due To Affiliate Commissions Paid DueToAffiliateCommissionsPaid	-0	USD
CY2019	tdw	Due To Affiliate Commissions Paid DueToAffiliateCommissionsPaid	5961000	USD
CY2018	tdw	Due To Affiliate Commissions Paid DueToAffiliateCommissionsPaid	13906000	USD
CY2020	tdw	Due To Related Party Amount Used To Offset Obligations DueToRelatedPartyAmountUsedToOffsetObligations	11848000	USD
CY2019	tdw	Due To Related Party Amount Used To Offset Obligations DueToRelatedPartyAmountUsedToOffsetObligations	10551000	USD
CY2018	tdw	Due To Related Party Amount Used To Offset Obligations DueToRelatedPartyAmountUsedToOffsetObligations	78993000	USD
CY2020	tdw	Due To Affiliate Other Increase Decrease DueToAffiliateOtherIncreaseDecrease	-49000	USD
CY2019	tdw	Due To Affiliate Other Increase Decrease DueToAffiliateOtherIncreaseDecrease	4049000	USD
CY2018	tdw	Due To Affiliate Other Increase Decrease DueToAffiliateOtherIncreaseDecrease	2518000	USD
CY2020Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	32767000	USD
CY2019Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	31475000	USD
CY2018Q4	us-gaap	Due To Affiliate Current And Noncurrent DueToAffiliateCurrentAndNoncurrent	29347000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-137225000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-44205000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Foreign IncomeLossFromContinuingOperationsBeforeIncomeTaxesForeign	-99607000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-60436000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-69290000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Domestic IncomeLossFromContinuingOperationsBeforeIncomeTaxesDomestic	-53912000	USD
CY2020	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-197661000	USD
CY2019	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-113495000	USD
CY2018	us-gaap	Income Loss From Continuing Operations Before Income Taxes Extraordinary Items Noncontrolling Interest IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest	-153519000	USD
CY2019	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2020	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	1254000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18252000	USD
CY2018	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	962000	USD
CY2018	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2018	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	16718000	USD
CY2018	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	17680000	USD
CY2018	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	531000	USD
CY2018	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	250000	USD
CY2018	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	-209000	USD
CY2018	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	572000	USD
CY2018	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	1493000	USD
CY2018	us-gaap	State And Local Income Tax Expense Benefit Continuing Operations StateAndLocalIncomeTaxExpenseBenefitContinuingOperations	250000	USD
CY2018	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	16509000	USD
CY2018	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	18252000	USD
CY2019	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	649000	USD
CY2019	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	26403000	USD
CY2019	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	27052000	USD
CY2019	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	672000	USD
CY2019	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	USD
CY2019	us-gaap	Deferred Foreign Income Tax Expense Benefit DeferredForeignIncomeTaxExpenseBenefit	0	USD
CY2019	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	672000	USD
CY2019	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	1321000	USD
CY2019	us-gaap	State And Local Income Tax Expense Benefit Continuing Operations StateAndLocalIncomeTaxExpenseBenefitContinuingOperations	0	USD
CY2019	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	26403000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	27724000	USD
CY2020	us-gaap	Current Federal Tax Expense Benefit CurrentFederalTaxExpenseBenefit	-21005000	USD
CY2020	us-gaap	Current State And Local Tax Expense Benefit CurrentStateAndLocalTaxExpenseBenefit	0	USD
CY2020	us-gaap	Current Foreign Tax Expense Benefit CurrentForeignTaxExpenseBenefit	18816000	USD
CY2020	us-gaap	Current Income Tax Expense Benefit CurrentIncomeTaxExpenseBenefit	-2189000	USD
CY2020	us-gaap	Deferred Federal Income Tax Expense Benefit DeferredFederalIncomeTaxExpenseBenefit	-30000	USD
CY2020	us-gaap	Deferred State And Local Income Tax Expense Benefit DeferredStateAndLocalIncomeTaxExpenseBenefit	0	USD
CY2020	us-gaap	Deferred Income Tax Expense Benefit DeferredIncomeTaxExpenseBenefit	1224000	USD
CY2020	us-gaap	Federal Income Tax Expense Benefit Continuing Operations FederalIncomeTaxExpenseBenefitContinuingOperations	-21035000	USD
CY2020	us-gaap	State And Local Income Tax Expense Benefit Continuing Operations StateAndLocalIncomeTaxExpenseBenefitContinuingOperations	0	USD
CY2020	us-gaap	Foreign Income Tax Expense Benefit Continuing Operations ForeignIncomeTaxExpenseBenefitContinuingOperations	20070000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-965000	USD
CY2020	us-gaap	Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate	0.21	pure
CY2018	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAmount	0	USD
CY2020	tdw	Income Tax Reconciliation Increase Decrease In Foreign Taxes IncomeTaxReconciliationIncreaseDecreaseInForeignTaxes	-12520000	USD
CY2019	tdw	Income Tax Reconciliation Increase Decrease In Foreign Taxes IncomeTaxReconciliationIncreaseDecreaseInForeignTaxes	-20778000	USD
CY2018	tdw	Income Tax Reconciliation Increase Decrease In Foreign Taxes IncomeTaxReconciliationIncreaseDecreaseInForeignTaxes	-13012000	USD
CY2020	tdw	Increased Current And Projected Liquidity IncreasedCurrentAndProjectedLiquidity	-0	USD
CY2020	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-41509000	USD
CY2019	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-23834000	USD
CY2018	us-gaap	Income Tax Reconciliation Income Tax Expense Benefit At Federal Statutory Income Tax Rate IncomeTaxReconciliationIncomeTaxExpenseBenefitAtFederalStatutoryIncomeTaxRate	-32239000	USD
CY2020	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	27639000	USD
CY2019	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	9283000	USD
CY2018	us-gaap	Income Tax Reconciliation Foreign Income Tax Rate Differential IncomeTaxReconciliationForeignIncomeTaxRateDifferential	20917000	USD
CY2020	tdw	Income Tax Reconciliation Uncertain Tax Position IncomeTaxReconciliationUncertainTaxPosition	-62833000	USD
CY2019	tdw	Income Tax Reconciliation Uncertain Tax Position IncomeTaxReconciliationUncertainTaxPosition	5145000	USD
CY2018	tdw	Income Tax Reconciliation Uncertain Tax Position IncomeTaxReconciliationUncertainTaxPosition	2264000	USD
CY2020	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	0	USD
CY2019	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	0	USD
CY2018	us-gaap	Income Tax Reconciliation Nondeductible Expense IncomeTaxReconciliationNondeductibleExpense	1091000	USD
CY2020	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	43455000	USD
CY2019	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	15707000	USD
CY2018	us-gaap	Income Tax Reconciliation Change In Deferred Tax Assets Valuation Allowance IncomeTaxReconciliationChangeInDeferredTaxAssetsValuationAllowance	38778000	USD
CY2020	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Valuation Allowance Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpValuationAllowanceAmount	-6523000	USD
CY2019	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Valuation Allowance Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpValuationAllowanceAmount	0	USD
CY2018	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Valuation Allowance Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpValuationAllowanceAmount	0	USD
CY2020	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAmount	6523000	USD
CY2019	tdw	Effective Income Tax Rate Reconciliation Deferred Tax True Up Amount EffectiveIncomeTaxRateReconciliationDeferredTaxTrueUpAmount	0	USD
CY2019	tdw	Increased Current And Projected Liquidity IncreasedCurrentAndProjectedLiquidity	-0	USD
CY2018	tdw	Increased Current And Projected Liquidity IncreasedCurrentAndProjectedLiquidity	-246000	USD
CY2020	tdw	Income Tax Reconciliation Return To Accrual IncomeTaxReconciliationReturnToAccrual	11401000	USD
CY2019	tdw	Income Tax Reconciliation Return To Accrual IncomeTaxReconciliationReturnToAccrual	-2247000	USD
CY2018	tdw	Income Tax Reconciliation Return To Accrual IncomeTaxReconciliationReturnToAccrual	-28176000	USD
CY2020	tdw	Income Tax Reconciliation Executive Compensation IncomeTaxReconciliationExecutiveCompensation	286000	USD
CY2019	tdw	Income Tax Reconciliation Executive Compensation IncomeTaxReconciliationExecutiveCompensation	28000	USD
CY2018	tdw	Income Tax Reconciliation Executive Compensation IncomeTaxReconciliationExecutiveCompensation	2818000	USD
CY2020	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	-5631000	USD
CY2019	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	-1227000	USD
CY2018	us-gaap	Income Tax Reconciliation Tax Exempt Income IncomeTaxReconciliationTaxExemptIncome	-0	USD
CY2020	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	2445000	USD
CY2019	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	1637000	USD
CY2018	us-gaap	Income Tax Reconciliation Other Adjustments IncomeTaxReconciliationOtherAdjustments	-459000	USD
CY2020	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	-965000	USD
CY2019	us-gaap	Income Tax Expense Benefit IncomeTaxExpenseBenefit	27724000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	8815000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Pensions DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsPensions	7422000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	407000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Compensation And Benefits Share Based Compensation Cost DeferredTaxAssetsTaxDeferredExpenseCompensationAndBenefitsShareBasedCompensationCost	972000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	148699000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Operating Loss Carryforwards DeferredTaxAssetsOperatingLossCarryforwards	99281000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Restructuring Charges DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringCharges	1415000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Tax Deferred Expense Reserves And Accruals Restructuring Charges DeferredTaxAssetsTaxDeferredExpenseReservesAndAccrualsRestructuringCharges	2264000	USD
CY2020Q4	us-gaap	Deferred Tax Asset Interest Carryforward DeferredTaxAssetInterestCarryforward	5546000	USD
CY2019Q4	us-gaap	Deferred Tax Asset Interest Carryforward DeferredTaxAssetInterestCarryforward	5105000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	2518000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Other DeferredTaxAssetsOther	3380000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	167400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Gross DeferredTaxAssetsGross	118424000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	140428000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	103496000	USD
CY2020Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	26972000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Net DeferredTaxAssetsNet	14928000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	25883000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Property Plant And Equipment DeferredTaxLiabilitiesPropertyPlantAndEquipment	11246000	USD
CY2020Q4	tdw	Deferred Tax Liability Outside Basis Difference DeferredTaxLiabilityOutsideBasisDifference	2891000	USD
CY2019Q4	tdw	Deferred Tax Liability Outside Basis Difference DeferredTaxLiabilityOutsideBasisDifference	2892000	USD
CY2020Q4	tdw	Deferred Tax Liabilities Foreign Interest Withholding Tax DeferredTaxLiabilitiesForeignInterestWithholdingTax	859000	USD
CY2019Q4	tdw	Deferred Tax Liabilities Foreign Interest Withholding Tax DeferredTaxLiabilitiesForeignInterestWithholdingTax	-0	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	754000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities Other DeferredTaxLiabilitiesOther	2981000	USD
CY2020Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	30387000	USD
CY2019Q4	us-gaap	Deferred Income Tax Liabilities DeferredIncomeTaxLiabilities	17119000	USD
CY2020Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	3415000	USD
CY2019Q4	us-gaap	Deferred Tax Liabilities DeferredTaxLiabilities	2191000	USD
CY2020	tdw	Income Tax Benefit Cares Act IncomeTaxBenefitCaresAct	6900000	USD
CY2020	tdw	Additional Interest Expense Deduction Cares Act AdditionalInterestExpenseDeductionCARESAct	6000000.0	USD
CY2020	tdw	Annual Limitation Of Companys Ownership Change AnnualLimitationOfCompanysOwnershipChange	15000000.0	USD
CY2020Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	140400000	USD
CY2019Q4	us-gaap	Deferred Tax Assets Valuation Allowance DeferredTaxAssetsValuationAllowance	103500000	USD
CY2020Q4	us-gaap	Undistributed Earnings Of Foreign Subsidiaries UndistributedEarningsOfForeignSubsidiaries	140800000	USD
CY2020Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	35304000	USD
CY2019Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	48577000	USD
CY2020Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	15928000	USD
CY2019Q4	us-gaap	Taxes Payable Current TaxesPayableCurrent	13760000	USD
CY2020Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	8280000	USD
CY2019Q4	us-gaap	Income Taxes Receivable IncomeTaxesReceivable	3798000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued	22100000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits Income Tax Penalties Accrued UnrecognizedTaxBenefitsIncomeTaxPenaltiesAccrued	24800000	USD
CY2017Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	404571000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Acquisition UnrecognizedTaxBenefitsIncreasesResultingFromAcquisition	8857000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	6903000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	2953000	USD
CY2018	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	18086000	USD
CY2018Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	399292000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Current Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromCurrentPeriodTaxPositions	14741000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	1964000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	1897000	USD
CY2019	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	58000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	414042000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Increases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsIncreasesResultingFromPriorPeriodTaxPositions	2223000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Reductions Resulting From Lapse Of Applicable Statute Of Limitations UnrecognizedTaxBenefitsReductionsResultingFromLapseOfApplicableStatuteOfLimitations	64458000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Decreases Resulting From Prior Period Tax Positions UnrecognizedTaxBenefitsDecreasesResultingFromPriorPeriodTaxPositions	760000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits UnrecognizedTaxBenefits	351047000	USD
CY2020Q4	tdw	Foreign Tax Credits And Other Tax Attributes ForeignTaxCreditsAndOtherTaxAttributes	337900000	USD
CY2020	us-gaap	Unrecognized Tax Benefits Period Increase Decrease UnrecognizedTaxBenefitsPeriodIncreaseDecrease	5900000	USD
CY2020Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	35300000	USD
CY2019Q4	us-gaap	Unrecognized Tax Benefits That Would Impact Effective Tax Rate UnrecognizedTaxBenefitsThatWouldImpactEffectiveTaxRate	48600000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due After Year Five LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive	547000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due LesseeOperatingLeaseLiabilityPaymentsDue	4222000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Undiscounted Excess Amount LesseeOperatingLeaseLiabilityUndiscountedExcessAmount	420000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Next Twelve Months LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths	1318000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Two LesseeOperatingLeaseLiabilityPaymentsDueYearTwo	1094000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Three LesseeOperatingLeaseLiabilityPaymentsDueYearThree	717000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Four LesseeOperatingLeaseLiabilityPaymentsDueYearFour	273000	USD
CY2020Q4	us-gaap	Lessee Operating Lease Liability Payments Due Year Five LesseeOperatingLeaseLiabilityPaymentsDueYearFive	273000	USD
CY2020	us-gaap	Operating Lease Cost OperatingLeaseCost	1270000	USD
CY2019	us-gaap	Operating Lease Cost OperatingLeaseCost	1336000	USD
CY2020	us-gaap	Short Term Lease Cost ShortTermLeaseCost	3483000	USD
CY2019	us-gaap	Short Term Lease Cost ShortTermLeaseCost	4840000	USD
CY2020	us-gaap	Variable Lease Cost VariableLeaseCost	392000	USD
CY2019	us-gaap	Variable Lease Cost VariableLeaseCost	313000	USD
CY2020	us-gaap	Sublease Income SubleaseIncome	-0	USD
CY2019	us-gaap	Sublease Income SubleaseIncome	3000	USD
CY2020	us-gaap	Lease Cost LeaseCost	5145000	USD
CY2019	us-gaap	Lease Cost LeaseCost	6486000	USD
CY2020Q4	us-gaap	Operating Lease Weighted Average Remaining Lease Term1 OperatingLeaseWeightedAverageRemainingLeaseTerm1	P3Y1M6D
CY2020Q4	us-gaap	Operating Lease Weighted Average Discount Rate Percent OperatingLeaseWeightedAverageDiscountRatePercent	0.073	pure
CY2020	us-gaap	Operating Lease Payments OperatingLeasePayments	1000000.0	USD
CY2019	us-gaap	Operating Lease Payments OperatingLeasePayments	1400000	USD
CY2020	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	300000	USD
CY2019	us-gaap	Right Of Use Asset Obtained In Exchange For Operating Lease Liability RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability	800000	USD
CY2019Q4	tdw	Number Of Vessels Held For Sale Addition NumberOfVesselsHeldForSaleAddition	46	pure
CY2019Q4	tdw	Number Of Vessels Held For Sale Addition Percentage NumberOfVesselsHeldForSaleAdditionPercentage	0.20	pure
	tdw	Number Of Vessels Held For Sale Addition NumberOfVesselsHeldForSaleAddition	32	pure
CY2020	tdw	Number Of Vessels Held For Sale Sold NumberOfVesselsHeldForSaleSold	53	pure
CY2020Q4	tdw	Number Of Vessels Held For Sale NumberOfVesselsHeldForSale	23	pure
CY2018Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	90247000	USD
CY2017Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	103443000	USD
CY2020	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Benefit Obligation DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation	0	USD
CY2019	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Benefit Obligation DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation	0	USD
CY2020	us-gaap	Impairment Of Long Lived Assets To Be Disposed Of ImpairmentOfLongLivedAssetsToBeDisposedOf	75200000	USD
CY2011Q4	us-gaap	Other Assets OtherAssets	1800000	USD
CY2019	tdw	Unpaid Milestone Payments UnpaidMilestonePayments	4000000.0	USD
CY2019Q4	tdw	Impairment Charge On Under Construction Asset ImpairmentChargeOnUnderConstructionAsset	5800000	USD
CY2020Q4	tdw	Expense Recovered On Contract To Shipyard ExpenseRecoveredOnContractToShipyard	4000000.0	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	74109000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	37773000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	61132000	USD
CY2020Q4	tdw	Defined Benefit Plan Concentration Risk Assets Equity Securities Difference Plan Assets And Liabilities DefinedBenefitPlanConcentrationRiskAssetsEquitySecuritiesDifferencePlanAssetsAndLiabilities	0.25	pure
CY2019Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	91654000	USD
CY2018	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Benefit Obligation DefinedBenefitPlanBusinessCombinationsAndAcquisitionsBenefitObligation	5474000	USD
CY2020	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	112000	USD
CY2019	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	427000	USD
CY2018	tdw	Defined Benefit Plan Plan Assets Actuarial Gain Loss DefinedBenefitPlanPlanAssetsActuarialGainLoss	-275000	USD
CY2020	tdw	Defined Benefit Plan Administrative Expenses DefinedBenefitPlanAdministrativeExpenses	49000	USD
CY2019	tdw	Defined Benefit Plan Administrative Expenses DefinedBenefitPlanAdministrativeExpenses	68000	USD
CY2018	us-gaap	Defined Benefit Plan Service Cost DefinedBenefitPlanServiceCost	294000	USD
CY2020	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	2907000	USD
CY2019	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	3751000	USD
CY2018	us-gaap	Defined Benefit Plan Interest Cost DefinedBenefitPlanInterestCost	3605000	USD
CY2020	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	5990000	USD
CY2019	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	5967000	USD
CY2018	us-gaap	Defined Benefit Plan Benefit Obligation Benefits Paid DefinedBenefitPlanBenefitObligationBenefitsPaid	5467000	USD
CY2020	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	-5277000	USD
CY2019	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	-8198000	USD
CY2018	us-gaap	Defined Benefit Plan Actuarial Gain Loss DefinedBenefitPlanActuarialGainLoss	8105000	USD
CY2020	us-gaap	Defined Benefit Plan Settlements Benefit Obligation DefinedBenefitPlanSettlementsBenefitObligation	4407000	USD
CY2019	us-gaap	Defined Benefit Plan Settlements Benefit Obligation DefinedBenefitPlanSettlementsBenefitObligation	4978000	USD
CY2018	us-gaap	Defined Benefit Plan Settlements Benefit Obligation DefinedBenefitPlanSettlementsBenefitObligation	8885000	USD
CY2020	us-gaap	Defined Benefit Plan Foreign Currency Exchange Rate Changes Benefit Obligation DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation	593000	USD
CY2019	us-gaap	Defined Benefit Plan Foreign Currency Exchange Rate Changes Benefit Obligation DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation	24000	USD
CY2018	us-gaap	Defined Benefit Plan Foreign Currency Exchange Rate Changes Benefit Obligation DefinedBenefitPlanForeignCurrencyExchangeRateChangesBenefitObligation	112000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	88960000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	91654000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	90247000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	59625000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	56790000	USD
CY2017Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	57536000	USD
CY2020	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Plan Assets DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets	0	USD
CY2019	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Plan Assets DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets	0	USD
CY2018	us-gaap	Defined Benefit Plan Business Combinations And Acquisitions Plan Assets DefinedBenefitPlanBusinessCombinationsAndAcquisitionsPlanAssets	5463000	USD
CY2020	us-gaap	Defined Benefit Plan Actual Return On Plan Assets DefinedBenefitPlanActualReturnOnPlanAssets	6890000	USD
CY2019	us-gaap	Defined Benefit Plan Actual Return On Plan Assets DefinedBenefitPlanActualReturnOnPlanAssets	7498000	USD
CY2018	us-gaap	Defined Benefit Plan Actual Return On Plan Assets DefinedBenefitPlanActualReturnOnPlanAssets	-2128000	USD
CY2020	tdw	Defined Benefit Plan Expected Return Loss On Plan Assets Debit Duration DefinedBenefitPlanExpectedReturnLossOnPlanAssetsDebitDuration	0	USD
CY2019	tdw	Defined Benefit Plan Expected Return Loss On Plan Assets Debit Duration DefinedBenefitPlanExpectedReturnLossOnPlanAssetsDebitDuration	0	USD
CY2018	tdw	Defined Benefit Plan Expected Return Loss On Plan Assets Debit Duration DefinedBenefitPlanExpectedReturnLossOnPlanAssetsDebitDuration	112000	USD
CY2020	tdw	Defined Benefit Plan Plan Assets Actuarial Gain Loss DefinedBenefitPlanPlanAssetsActuarialGainLoss	18000	USD
CY2019	tdw	Defined Benefit Plan Plan Assets Actuarial Gain Loss DefinedBenefitPlanPlanAssetsActuarialGainLoss	983000	USD
CY2018	tdw	Defined Benefit Plan Administrative Expenses DefinedBenefitPlanAdministrativeExpenses	36000	USD
CY2020	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	1615000	USD
CY2019	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	5027000	USD
CY2018	us-gaap	Defined Benefit Plan Contributions By Employer DefinedBenefitPlanContributionsByEmployer	10546000	USD
CY2020	us-gaap	Defined Benefit Plan Plan Assets Benefits Paid DefinedBenefitPlanPlanAssetsBenefitsPaid	5990000	USD
CY2019	us-gaap	Defined Benefit Plan Plan Assets Benefits Paid DefinedBenefitPlanPlanAssetsBenefitsPaid	5967000	USD
CY2018	us-gaap	Defined Benefit Plan Plan Assets Benefits Paid DefinedBenefitPlanPlanAssetsBenefitsPaid	5467000	USD
CY2020	us-gaap	Defined Benefit Plan Settlements Plan Assets DefinedBenefitPlanSettlementsPlanAssets	5000000	USD
CY2019	us-gaap	Defined Benefit Plan Settlements Plan Assets DefinedBenefitPlanSettlementsPlanAssets	4638000	USD
CY2018	us-gaap	Defined Benefit Plan Settlements Plan Assets DefinedBenefitPlanSettlementsPlanAssets	8885000	USD
CY2020	us-gaap	Defined Benefit Plan Plan Assets Foreign Currency Translation Gain Loss DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss	-614000	USD
CY2019	us-gaap	Defined Benefit Plan Plan Assets Foreign Currency Translation Gain Loss DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss	0	USD
CY2018	us-gaap	Defined Benefit Plan Plan Assets Foreign Currency Translation Gain Loss DefinedBenefitPlanPlanAssetsForeignCurrencyTranslationGainLoss	-76000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	56495000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	59625000	USD
CY2018Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	56790000	USD
CY2020	tdw	Defined Benefit Plan Payroll Tax Unrecognized In Plan Assets DefinedBenefitPlanPayrollTaxUnrecognizedInPlanAssets	0	USD
CY2019	tdw	Defined Benefit Plan Payroll Tax Unrecognized In Plan Assets DefinedBenefitPlanPayrollTaxUnrecognizedInPlanAssets	0	USD
CY2018	tdw	Defined Benefit Plan Payroll Tax Unrecognized In Plan Assets DefinedBenefitPlanPayrollTaxUnrecognizedInPlanAssets	84000	USD
CY2020	tdw	Defined Benefit Plan Unfunded Status Of Plan DefinedBenefitPlanUnfundedStatusOfPlan	32465000	USD
CY2019	tdw	Defined Benefit Plan Unfunded Status Of Plan DefinedBenefitPlanUnfundedStatusOfPlan	32029000	USD
CY2018	tdw	Defined Benefit Plan Unfunded Status Of Plan DefinedBenefitPlanUnfundedStatusOfPlan	33541000	USD
CY2020Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	1524000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	1422000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Current Liabilities PensionAndOtherPostretirementDefinedBenefitPlansCurrentLiabilities	1380000	USD
CY2020Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	30941000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	30607000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesNoncurrent	32161000	USD
CY2020Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Current And Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent	32465000	USD
CY2019Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Current And Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent	32029000	USD
CY2018Q4	us-gaap	Pension And Other Postretirement Defined Benefit Plans Liabilities Current And Noncurrent PensionAndOtherPostretirementDefinedBenefitPlansLiabilitiesCurrentAndNoncurrent	33541000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	88960000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Benefit Obligation DefinedBenefitPlanBenefitObligation	91654000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	88960000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Accumulated Benefit Obligation DefinedBenefitPlanAccumulatedBenefitObligation	91109000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	56495000	USD
CY2019Q4	us-gaap	Defined Benefit Plan Fair Value Of Plan Assets DefinedBenefitPlanFairValueOfPlanAssets	59625000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.025	pure
CY2019Q4	us-gaap	Defined Benefit Plan Assumptions Used Calculating Benefit Obligation Discount Rate DefinedBenefitPlanAssumptionsUsedCalculatingBenefitObligationDiscountRate	0.035	pure
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	1591577
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	2187101
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant	2325102
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Next Twelve Months DefinedBenefitPlanExpectedFutureBenefitPaymentsNextTwelveMonths	5860000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Two DefinedBenefitPlanExpectedFutureBenefitPaymentsYearTwo	5833000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Three DefinedBenefitPlanExpectedFutureBenefitPaymentsYearThree	5777000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Four DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFour	5762000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Year Five DefinedBenefitPlanExpectedFutureBenefitPaymentsYearFive	5686000	USD
CY2020Q4	us-gaap	Defined Benefit Plan Expected Future Benefit Payments Five Fiscal Years Thereafter DefinedBenefitPlanExpectedFutureBenefitPaymentsFiveFiscalYearsThereafter	26605000	USD
CY2020Q4	tdw	Defined Benefit Plan Expected Future Benefit Payments DefinedBenefitPlanExpectedFutureBenefitPayments	55523000	USD
CY2020	tdw	Defined Contribution Plan Company Contribution Percentage DefinedContributionPlanCompanyContributionPercentage	0.03	pure
CY2020Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	3973228
CY2019Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	3973228
CY2018Q4	us-gaap	Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized	3973228
CY2020	tdw	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodGrantDateFairValue	6395000	USD
CY2019	tdw	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodGrantDateFairValue	19193000	USD
CY2018	tdw	Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period Grant Date Fair Value ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodGrantDateFairValue	12513000	USD
CY2020Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	125000000
CY2019Q4	us-gaap	Common Stock Shares Authorized CommonStockSharesAuthorized	125000000
CY2020Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
CY2019Q4	us-gaap	Common Stock Par Or Stated Value Per Share CommonStockParOrStatedValuePerShare	0.001
CY2020Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	40704984
CY2019Q4	us-gaap	Common Stock Shares Issued CommonStockSharesIssued	39941327
CY2020Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	3000000
CY2019Q4	us-gaap	Preferred Stock Shares Authorized PreferredStockSharesAuthorized	3000000
CY2020Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2019Q4	us-gaap	Preferred Stock Shares Issued PreferredStockSharesIssued	0
CY2017	tdw	Class Of Warrant Or Right Issued During Period ClassOfWarrantOrRightIssuedDuringPeriod	11543814
CY2020Q2	tdw	Percentage Of Ownership Of Outstanding Common Stock Subject To Dilution PercentageOfOwnershipOfOutstandingCommonStockSubjectToDilution	0.0499	pure
CY2020Q2	tdw	Percentage Of Ownership Of Outstanding Common Stock Subject To Dilution PercentageOfOwnershipOfOutstandingCommonStockSubjectToDilution	0.0499	pure
CY2020Q2	tdw	Percentage Of Additional Ownership Over499 In Otustanding Common Stock Subject To Dilution PercentageOfAdditionalOwnershipOver499InOtustandingCommonStockSubjectToDilution	0.005	pure
CY2020Q2	tdw	Number Of Rights Issued Per Common Stock Owned NumberOfRightsIssuedPerCommonStockOwned	1
CY2020Q4	tdw	Accrued Vessel Expenses AccruedVesselExpenses	17129000	USD
CY2019Q4	tdw	Accrued Vessel Expenses AccruedVesselExpenses	38383000	USD
CY2020Q4	us-gaap	Interest Payable Current InterestPayableCurrent	3240000	USD
CY2019Q4	us-gaap	Interest Payable Current InterestPayableCurrent	4570000	USD
CY2020Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	14852000	USD
CY2019Q4	us-gaap	Other Accrued Liabilities Current OtherAccruedLiabilitiesCurrent	14696000	USD
CY2020Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	52422000	USD
CY2019Q4	us-gaap	Accrued Liabilities Current AccruedLiabilitiesCurrent	74000000	USD
CY2018	us-gaap	Operating Lease Expense OperatingLeaseExpense	3800000	USD
CY2020Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	17201000	USD
CY2019Q4	us-gaap	Employee Related Liabilities Current EmployeeRelatedLiabilitiesCurrent	16351000	USD
CY2020Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	23883000	USD
CY2019Q4	us-gaap	Accrued Income Taxes Current AccruedIncomeTaxesCurrent	18661000	USD
CY2020Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	8902000	USD
CY2019Q4	us-gaap	Other Sundry Liabilities Current OtherSundryLiabilitiesCurrent	5439000	USD
CY2020Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	32785000	USD
CY2019Q4	us-gaap	Other Liabilities Current OtherLiabilitiesCurrent	24100000	USD
CY2020Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	31736000	USD
CY2019Q4	us-gaap	Defined Benefit Pension Plan Liabilities Noncurrent DefinedBenefitPensionPlanLiabilitiesNoncurrent	32545000	USD
CY2020Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	35304000	USD
CY2019Q4	us-gaap	Liability For Uncertain Tax Positions Noncurrent LiabilityForUncertainTaxPositionsNoncurrent	48577000	USD
CY2020Q4	us-gaap	Other Sundry Liabilities Noncurrent OtherSundryLiabilitiesNoncurrent	12752000	USD
CY2019Q4	us-gaap	Other Sundry Liabilities Noncurrent OtherSundryLiabilitiesNoncurrent	17275000	USD
CY2019	us-gaap	Gross Profit GrossProfit	6894000	USD
CY2018	us-gaap	Gross Profit GrossProfit	6066000	USD
CY2020	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	7591000	USD
CY2020	us-gaap	Operating Income Loss OperatingIncomeLoss	-186802000	USD
CY2019	us-gaap	Operating Income Loss OperatingIncomeLoss	-86604000	USD
CY2018	us-gaap	Operating Income Loss OperatingIncomeLoss	-107497000	USD
CY2020	us-gaap	Depreciation And Amortization DepreciationAndAmortization	116709000	USD
CY2019	us-gaap	Depreciation And Amortization DepreciationAndAmortization	101931000	USD
CY2020Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	79792000	USD
CY2019Q4	us-gaap	Other Liabilities Noncurrent OtherLiabilitiesNoncurrent	98397000	USD
CY2020	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	397038000	USD
CY2019	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	486549000	USD
CY2018	us-gaap	Revenue From Contract With Customer Excluding Assessed Tax RevenueFromContractWithCustomerExcludingAssessedTax	406520000	USD
CY2020	us-gaap	Gross Profit GrossProfit	-29670000	USD
CY2019	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	2263000	USD
CY2018	us-gaap	Gain Loss On Disposition Of Assets1 GainLossOnDispositionOfAssets1	10624000	USD
CY2020	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	52981000	USD
CY2019	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-0	USD
CY2018	us-gaap	Provision For Doubtful Accounts ProvisionForDoubtfulAccounts	-0	USD
CY2020	us-gaap	Affiliate Costs AffiliateCosts	2000000	USD
CY2019	us-gaap	Affiliate Costs AffiliateCosts	-0	USD
CY2018	us-gaap	Affiliate Costs AffiliateCosts	-0	USD
CY2020	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	-0	USD
CY2019	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	-0	USD
CY2018	tdw	Impairment Of Due From Affiliate ImpairmentOfDueFromAffiliate	20083000	USD
CY2020	us-gaap	Asset Impairment Charges AssetImpairmentCharges	74109000	USD
CY2019	us-gaap	Asset Impairment Charges AssetImpairmentCharges	37773000	USD
CY2018	us-gaap	Asset Impairment Charges AssetImpairmentCharges	61132000	USD
CY2018	us-gaap	Depreciation And Amortization DepreciationAndAmortization	58293000	USD
CY2020	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	14900000	USD
CY2019	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	17998000	USD
CY2018	us-gaap	Property Plant And Equipment Additions PropertyPlantAndEquipmentAdditions	21391000	USD
CY2020Q4	us-gaap	Equity Method Investments EquityMethodInvestments	0	USD
CY2019Q4	us-gaap	Equity Method Investments EquityMethodInvestments	0	USD
CY2018Q4	us-gaap	Equity Method Investments EquityMethodInvestments	8479000	USD
CY2020Q4	us-gaap	Assets Assets	1251177000	USD
CY2019Q4	us-gaap	Assets Assets	1579528000	USD
CY2018Q4	us-gaap	Assets Assets	1827739000	USD
CY2018Q4	tdw	Business Exit Costs And Severance Charges BusinessExitCostsAndSeveranceCharges	7300000	USD
CY2019	tdw	Business Exit Costs And Severance Charges BusinessExitCostsAndSeveranceCharges	6800000	USD
CY2020	tdw	Business Exit Costs And Severance Charges BusinessExitCostsAndSeveranceCharges	1500000	USD
CY2018Q4	us-gaap	Restructuring Reserve RestructuringReserve	6753000	USD
CY2019	us-gaap	Restructuring Charges RestructuringCharges	6822000	USD
CY2019	us-gaap	Payments For Restructuring PaymentsForRestructuring	9194000	USD
CY2019Q4	us-gaap	Restructuring Reserve RestructuringReserve	4381000	USD
CY2020	us-gaap	Restructuring Charges RestructuringCharges	1501000	USD
CY2020	us-gaap	Payments For Restructuring PaymentsForRestructuring	2547000	USD
CY2020Q4	us-gaap	Restructuring Reserve RestructuringReserve	3335000	USD

Files In Submission

Name	View Source	Status
0001437749-21-005037-index-headers.html	Edgar Link	pending
0001437749-21-005037-index.html	Edgar Link	pending
0001437749-21-005037.txt	Edgar Link	pending
0001437749-21-005037-xbrl.zip	Edgar Link	pending
ex_223612.htm	Edgar Link	pending
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ex_231240.htm	Edgar Link	pending
FilingSummary.xml	Edgar Link	unprocessable
Financial_Report.xlsx	Edgar Link	pending
logo01.jpg	Edgar Link	pending
MetaLinks.json	Edgar Link	pending
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report.css	Edgar Link	pending
Show.js	Edgar Link	pending
tdw-20201231.xsd	Edgar Link	pending
tdw-20201231_cal.xml	Edgar Link	unprocessable
tdw-20201231_def.xml	Edgar Link	unprocessable
tdw-20201231_lab.xml	Edgar Link	unprocessable
tdw-20201231_pre.xml	Edgar Link	unprocessable
tdw20201231_10k.htm	Edgar Link	pending
tdw20201231_10k_htm.xml	Edgar Link	completed
tidewatergraph.jpg	Edgar Link	pending

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$TDW
TIDEWATER INC Stock $tdw

2020 Q4 Form 10-K Financial Statement

#000143774921005037 Filed on March 04, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TDW TIDEWATER INC Stock $tdw

2020 Q4 Form 10-K Financial Statement

#000143774921005037 Filed on March 04, 2021

Income Statement

Balance Sheet

Cashflow Statement

Facts In Submission

Files In Submission

$TDW
TIDEWATER INC Stock $tdw