Note 6 - Income Taxes (Details Textual) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2022	Dec. 31, 2021
Effective Income Tax Rate Reconciliation, at Federal Statutory Income Tax Rate, Percent	21.00%
Annual Limitation Of Companys Ownership Change		$ 15,000
Deferred Tax Assets, Valuation Allowance	$ 441,893	204,899
Undistributed Earnings of Foreign Subsidiaries	71,100
Unrecognized Tax Benefits, Income Tax Penalties Accrued	15,800	17,800
Foreign Tax Credits and Other Tax Attributes	157,700
Unrecognized Tax Benefits, Period Increase (Decrease), Total	11,900
Unrecognized Tax Benefits that Would Impact Effective Tax Rate	22,500	29,300
Gulf Mark Offshore Inc [Member]
Annual Limitation Of Companys Ownership Change		7,000
Domestic Tax Authority [Member]
Operating Loss Carryforwards	445,600	417,900
Domestic Tax Authority [Member] | IRC Section382 Limitation [Member]
Operating Loss Carryforwards	166,200	$ 163,700
Foreign Tax Authority [Member]
Operating Loss Carryforwards	415,700
Tax Credit Carryforward, Amount	405,300
Non U.S Foreign Country [Member]
Tax Credit Carryforward, Amount	$ 7,700