Note 8 - Income Taxes - Difference Between Expected Amount and Actual Amount, Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2021	Dec. 31, 2020
Expected amount	$ (783)	$ (1,865)
State income taxes, net of federal benefit	(767)	(644)
Percentage depletion	(1,725)	(2,154)
Valuation allowance	3,376	1,275
Stock-based compensation	380	67
PPP loan forgiveness	(2,100)	0
Return to provision adjustments	1,610	(60)
Other	35	723
Total income tax expense (benefit)	$ 26	$ (2,658)

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Amount of current income tax expense (benefit) and deferred income tax expense (benefit) pertaining to continuing operations.

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The amount of income tax expense or benefit for the period computed by applying the domestic federal statutory tax rates to pretax income from continuing operations.

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Amount of reported income tax expense (benefit) in excess of (less than) expected income tax expense (benefit) computed by applying domestic federal statutory income tax rate to pretax income (loss) from continuing operation, attributable to nondeductible expense for award under share-based payment arrangement. Includes, but is not limited to, expense determined to be nondeductible upon grant or after for award under share-based payment arrangement.

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