Note 2 - Summary of Significant Accounting Policies (Details Textual) shares in Thousands	12 Months Ended
Dec. 31, 2021 USD ($) shares	Dec. 31, 2020 USD ($) shares
Debt Securities, Available-for-sale, Accumulated Gross Unrealized Gain (Loss), before Tax, Total	$ 0	$ 0
Unrecognized Tax Benefits, Ending Balance	$ 0	$ 0
Weighted Average Number of Shares Outstanding, Diluted, Total (in shares) \| shares	0	0
Current Year Inflation Rate	4.08%
Change In Present Value, Percent	3.25%
Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Number of Major Customers	2	1
Oil and Gas [Member]
Contract with Customer, Asset, after Allowance for Credit Loss, Total	$ 584,336	$ 232,860
Oil and Gas [Member] \| Customer Concentration Risk [Member] \| Revenue Benchmark [Member]
Concentration Risk, Percentage	35.00%	17.00%

The percentage by which the liability is increased annually for the change in its present value.

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The current year inflation rate used to determine fair value.

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The number of major customers.

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- Definition

For an entity that discloses a concentration risk in relation to quantitative amount, which serves as the "benchmark" (or denominator) in the equation, this concept represents the concentration percentage derived from the division.

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Amount, after allowance for credit loss, of right to consideration in exchange for good or service transferred to customer when right is conditioned on something other than passage of time.

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Amount, before tax, of unrealized gain (loss) in accumulated other comprehensive income (AOCI) on investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Amount of unrecognized tax benefits.

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- Definition

The average number of shares or units issued and outstanding that are used in calculating diluted EPS or earnings per unit (EPU), determined based on the timing of issuance of shares or units in the period.

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