Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2023

Notes Tables

Schedule of Cash, Cash Equivalents and Restricted Cash [Table Text Block]

	As of December 31,
	2023		2022
	(in thousands)
Cash and cash equivalents	$	121,001	$	37,205
Restricted cash - current		114		222
Restricted cash - non-current		1,795		1,763
Abandonment funding		6,268		20,586
Total cash, cash equivalents and restricted cash	$	129,178	$	59,776

Accounts Receivable, Allowance for Credit Loss [Table Text Block]

	Twelve Months Ended December 31,
	2023			2022
	(in thousands)
Allowance for credit losses and other
Balance at beginning of period	$	(8,704	)	$	(5,741	)
Credit losses and other		(7,543	)		(3,380	)
Credit recoveries and other		12,449			298
Adjustment associated with Sasol Acquisition		—			—
Cumulative effect of adjustment upon adoption of ASU 2016-13 on January 1, 2023		(3,120	)		—
Foreign currency gain		889			119
Balance at end of period	$	(6,029	)	$	(8,704	)

Deferred Costs, Capitalized, Prepaid, and Other Assets Disclosure [Table Text Block]

	As of December 31, 2023		As of December 31, 2022
	(in thousands)
Prepaid fixed asset progress payments	$	2,314	$	3,991
Gabon prepaid royalties		1,246		4,800
Prepaid insurance		474		117
Egypt advances to contractors		2,656		4,914
Gabon employee loans and advances		1,299		1,146
Refundable deposits		345		623
Derivative receivables		403		102
Other prepayments		3,697		4,377
Total prepayments and other	$	12,434	$	20,070

Schedule of Fair Value, Assets and Liabilities Measured on Recurring Basis [Table Text Block]

		As of December 31, 2023
	Balance Sheet Line	Level 1		Level 2		Level 3		Total
		(in thousands)
Assets
Derivative asset	Prepayments and other	$	—	$	403	$	—	$	403
		$	—	$	403	$	—	$	403
Liabilities
SARs liability	Accrued liabilities and other	$	—	$	163	$	—	$	163
Derivative liability	Accrued liabilities and other		—		—		—		—
		$	—	$	163	$	—	$	163

		As of December 31, 2022
	Balance Sheet Line	Level 1		Level 2		Level 3		Total
		(in thousands)
Assets
Derivative asset	Prepayments and other	$	—	$	102	$	—	$	102
		$	—	$	102	$	—	$	102
Liabilities
SARs liability	Accrued liabilities and other	$	—	$	556	$	—	$	556
		$	—	$	556	$	—	$	556