Note 8 - Debt (Details Textual) $ in Thousands, € in Millions	Jul. 07, 2025 USD ($)	Jul. 05, 2023 USD ($)	Jun. 30, 2025 USD ($)	Jun. 30, 2025 EUR (€)	Dec. 31, 2024 USD ($)	Jul. 03, 2023 USD ($)	Nov. 16, 2021 USD ($)
Long-Term Debt, Current Maturities			$ 93,366		$ 65,386
Debt Instrument, Variable Interest Rate, Type [Extensible Enumeration]		Secured Overnight Financing Rate (SOFR) [Member]
Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity			25,000
Long-Term Line of Credit			0
Subsequent Event [Member] \| Revolving Credit Facility [Member]
Line of Credit Facility, Maximum Borrowing Capacity	$ 250,000
Minimum [Member] \| Subsequent Event [Member] \| Revolving Credit Facility [Member] \| Secured Overnight Financing Rate (SOFR) [Member]
Debt Instrument, Basis Spread on Variable Rate	2.50%
Minimum [Member] \| Subsequent Event [Member] \| Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	2.50%
Maximum [Member] \| Subsequent Event [Member] \| Revolving Credit Facility [Member] \| Secured Overnight Financing Rate (SOFR) [Member]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Maximum [Member] \| Subsequent Event [Member] \| Revolving Credit Facility [Member] \| Base Rate [Member]
Debt Instrument, Basis Spread on Variable Rate	3.50%
Nordic Bond [Member]
Debt Instrument, Interest Rate, Stated Percentage							8.50%
Debt Instrument, Face Amount							$ 175,000
Debt Instrument, Covenant, Prepayment Premium Percentage							2.55%
Debt Instrument, Covenant, Prepayment Premium Percentage, Increase (Decrease)							(0.85%)
Debt Instrument, Covenant, Minimum Free Liquidity Amount							$ 20,000
Debt Instrument, Covenant, Minimum Free Liquidity, Percentage of Net Interest Bearing Debt							10.00%
Debt Instrument, Covenant, Percentage of Minimum Equity Ratio							30.00%
Nordic Bond [Member] \| GOLP and TMII [Member]
Debt Instrument, Collateral, Percentage of Equity Interests							66.00%
Nordic Bond [Member] \| Subsequent Event [Member]
Repayments of Debt	$ 4,500
Vessel Facility Agreements [Member] \| Delivery of Vessels Per Arrangement [Member]
Debt Instrument, Face Amount			$ 26,700	€ 24.9
Vessel Facility Agreements [Member] \| Minimum [Member]
Debt Instrument, Interest Rate, Stated Percentage			2.70%	2.70%
Vessel Facility Agreements [Member] \| Maximum [Member]
Debt Instrument, Interest Rate, Stated Percentage			6.30%	6.30%
The 2023 Notes [Member] \| Subsequent Event [Member]
Debt Instrument, Interest Rate, Stated Percentage	9.125%
Debt Instrument, Face Amount	$ 650,000
The 2023 Notes [Member] \| Subsequent Event [Member] \| Debt Instrument, Redemption, Period One [Member]
Debt Instrument, Redemption Price, Percentage	100.00%
The 2023 Notes [Member] \| Subsequent Event [Member] \| Debt Instrument, Redemption, Period Two [Member]
Debt Instrument, Redemption Price, Percentage	104.563%
Secured Debt [Member]
Long-Term Debt, Fair Value			$ 192,500		218,200
Debt Instrument, Face Amount		$ 325,000
Debt Instrument, Covenant, Free Liquidity Test, Amount		$ 20,000
Debt Instrument, Covenant, Free Liquidity Test, Percentage		10.00%
Debt Instrument, Covenant, Minimum Equity Ratio		30.00%
Secured Debt [Member] \| Tranche A Term Loan [Member]
Long-Term Debt, Current Maturities		$ 50,000
Long-Term Line of Credit, Noncurrent		$ 50,000
Debt Instrument, Basis Spread on Variable Rate		5.00%
Secured Debt [Member] \| Tranche A Term Loan [Member] \| Maximum [Member]
Debt Instrument, Basis Spread on Variable Rate		8.00%
Secured Debt [Member] \| Tranche B Term Loan [Member]
Debt Instrument, Term (Year)		3 years
Debt Instrument, Final Payment		$ 50,000
Debt Instrument, Basis Spread on Variable Rate		3.75%
Secured Debt [Member] \| Tranche B Term Loan [Member] \| Minimum [Member]
Debt Instrument, Periodic Payment		$ 12,500
Secured Debt [Member] \| Tranche B Term Loan [Member] \| Maximum [Member]
Debt Instrument, Periodic Payment		$ 25,000
Unsecured Debt [Member]
Long-Term Debt, Fair Value			$ 265,200		$ 266,100
Debt Instrument, Interest Rate, Stated Percentage			10.375%	10.375%	10.375%	10.375%
Debt Instrument, Face Amount						$ 250,000
Debt Instrument, Covenant, Free Liquidity Test, Amount						$ 20,000
Debt Instrument, Covenant, Free Liquidity Test, Percentage						10.00%
Debt Instrument, Covenant, Minimum Equity Ratio						30.00%
Debt Instrument, Covenant, Prepayment Premium Percentage						6.00%
Unsecured Debt [Member] \| Subsequent Event [Member]
Repayments of Debt	$ 15,000
Nordic Bond [Member]
Long-Term Debt, Fair Value			$ 179,600		$ 180,800
Debt Instrument, Interest Rate, Stated Percentage			8.50%	8.50%	8.50%

TIDEWATER INC 10-Q