Note 1 - Organization and Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2020

Notes Tables

Restrictions on Cash and Cash Equivalents [Table Text Block]

	December 31, 2020		December 31, 2019
Cash and cash equivalents	$	10,640	$	10,914
Restricted cash included in current assets		1,595		2,080
Restricted cash included in long-term assets		371		507
Total cash, cash equivalents, and restricted cash shown in the Consolidated Statements of Cash Flows	$	12,606	$	13,501

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

Year	Balance at January 1		Provision charged to expense			Write-offs / Recoveries			Balance at December 31
2019	$	1,411	$	573		$	(168	)	$	1,816
2020	$	1,816	$	(498	)	$	(483	)	$	835

Schedule of Excess and Obsolete Inventory Reserve [Table Text Block]

Year	Balance at January 1		Provision charged to expense		Write-offs / Recoveries			Balance at December 31
2019		1,131		—		(131	)		1,000
2020		1,000		—		(93	)		907

Schedule of Accumulated Other Comprehensive Income (Loss) [Table Text Block]

	December 31,
	2020			2019
Foreign currency translation
Balance at beginning of period	$	(1,778	)	$	(1,285	)
Other comprehensive loss:
Foreign currency translation adjustments (1)		408			(493	)
Balance at end of period	$	(1,370	)	$	(1,778	)
Total accumulated other comprehensive loss	$	(1,370	)	$	(1,778	)

Schedule of Finite-Lived Intangible Assets [Table Text Block]

			2020							2019
Description of Other Intangibles	Amortization Period (years)		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount		Gross Carrying Amount		Accumulated Amortization			Net Carrying Amount
Patent assets		1 - 20		1,310		(757	)		553		1,897		(991	)		906
Total			$	1,310	$	(757	)	$	553	$	1,897	$	(991	)	$	906

Schedule of Finite-Lived Intangible Assets, Future Amortization Expense [Table Text Block]

Year	Estimated Amortization Expense
2021	$	145
2022		52
2023		51
2024		44
2025		43
Thereafter		218
Total	$	553

Property, Plant and Equipment [Table Text Block]

Description of Property and Equipment	Depreciable Life (years)		2020			2019
Land			$	1,050		$	1,050
Building		39		3,950			3,950
Building and leasehold improvements		3 - 39		2,886			2,886
Field equipment		3 - 4		19,748			19,507
Computer equipment and software		2 - 3		2,954			2,936
Furniture and fixtures		3 - 10		1,477			1,475
Vehicles		5		32			32
Construction in process				12			—
Total cost				32,109			31,836
Less accumulated depreciation				(26,889	)		(26,174	)
Total net book value			$	5,220		$	5,662

Schedule of Error Corrections and Prior Period Adjustments [Table Text Block]

	As Previously Reported Year Ended December 31, 2019		Revision			As Revised Year Ended December 31, 2019
Right of Use Operating Lease Asset		980		(618	)		362
Operating Lease Liability - Current		300		(118	)		182
Operating Lease Liability - Non Current		680		(500	)		180

Schedule of Earnings Per Share, Basic and Diluted [Table Text Block]

	2020		2019
Basic weighted-average shares		24,691,000		24,202,000
Conversion of unsecured loan notes		—		—
Unexercised options and unvested restricted stock units		—		—
Diluted weighted-average shares		24,691,000		24,202,000