Note 2 - Summary of Significant Accounting Policies (Tables)

12 Months Ended

Dec. 31, 2018

Notes Tables

Schedule of Accounts, Notes, Loans and Financing Receivable [Table Text Block]

(In thousands)	For the Years ended December 31,
	2018			2017			2016
Allowance for doubtful accounts, beginning of year	$	135		$	151		$	90
Charge (credit) to costs and expenses		33			(13	)		93
Deductions		(1	)		(3	)		(32	)
Allowance for doubtful accounts, end of year	$	167		$	135		$	151

Schedule of Inventory, Current [Table Text Block]

(In thousands)	As of December 31,
	2018			2017
Finished goods	$	10,143		$	10,792
Raw materials		4,200			3,287
Work-in-process		1,194			759
Inventory reserves		(2,495	)		(946	)
Total inventories	$	13,042		$	13,892

Schedule of Inventory Valuation Reserve [Table Text Block]

(In thousands)	For the Years ended December 31,
	2018			2017		2016
Inventory reserves, beginning of year	$	946		$	774	$	483
Charge to costs and expenses		1,592			138		312
Other (deductions) additions		(43	)		34		(21	)
Inventory reserves, end of year	$	2,495		$	946	$	774

Schedule of Useful Lives for Property Plant Equipment [Table Text Block]

	Estimated Useful Life (years)
Buildings and improvements		5	to	39
Furniture and equipment		3	to	10
Vehicles		3	to	5

Schedule of Estimated Useful Life [Table Text Block]

	Estimated
	Useful
	Life (years)
Finite-lived intangible assets
Order backlog			2
Trade name - Orbital			10
Trade name - V-Infinity			5
Trade name - CUI-Canada			3
Customer list - Orbital			10
Customer list - CUI-Canada			7
Technology rights			20 (1)
Technology-Based Asset - Know How			12
Technology-Based Asset - Software			10
Technology-Based Asset - Power			7
Software		3	to	5  (2)
Patents	See endnote (3)
Other intangible assets	See endnote (4)
Indefinite-lived intangible assets
Trade name - CUI	See endnote (5)
Customer list - CUI	See endnote (5)
Patents pending technology	See endnote (5)

Cumulative Effect of Adjustments for New Accounting Pronouncements on Balance Sheet [Table Text Block]

(in thousands)	Balance at December 31, 2017			Adjustments Due to ASC 606			Balance at January 1, 2018
Balance Sheet
Assets:
Inventories	$	13,892		$	(1,064	)	$	12,828
Contract assets		2,299			(516	)		1,783
Total current assets		41,276			(1,580	)		39,696
Total assets	$	87,909		$	(1,580	)	$	86,329
Liabilities:
Contract liabilities	$	8,829		$	(4,168	)	$	4,661
Refund liabilities		695			870			1,565
Total current liabilities		18,914			(3,298	)		15,616
Deferred tax liabilities		2,414			(173	)		2,241
Total liabilities		30,423			(3,471	)		26,952
Stockholders' Equity:
Accumulated deficit		(108,559	)		1,891			(106,668	)
Total stockholders' equity		57,486			1,891			59,377
Total liabilities and stockholders' equity	$	87,909		$	(1,580	)	$	86,329

Schedule of New Accounting Pronouncements and Changes in Accounting Principles [Table Text Block]

(In thousands, except per share amounts)	For the Year Ended December 31, 2018
	As Reported			Balances Without Adoption of ASC 606			Effect of Change Higher / (Lower)
Statement of Operations
Total revenues	$	96,789		$	91,417		$	5,372
Cost of revenues		67,879			64,495			3,384
Gross profit		28,910			26,922			1,988
Loss from operations		(16,778	)		(18,766	)		1,988
Loss before taxes		(17,531	)		(19,519	)		1,988
Income tax (benefit) expense		(206	)		(462	)		256
Net loss	$	(17,325	)	$	(19,057	)	$	1,732
Basic and diluted loss per common share	$	(0.61	)	$	(0.67	)	$	0.06

(in thousands)	As of December 31, 2018
	As Reported			Balances Without Adoption of ASC 606			Effect of Change Higher / (Lower)
Balance Sheet
Assets:
Inventories	$	13,042		$	17,578		$	(4,536	)
Contract assets		1,744			2,109			(365	)
Total current assets		35,481			40,382			(4,901	)
Total assets	$	70,167		$	75,068		$	(4,901	)
Liabilities:
Contract liabilities	$	2,226		$	12,203		$	(9,977	)
Refund liabilities		2,417			1,063			1,354
Total current liabilities		18,586			27,209			(8,623	)
Deferred tax liabilities		1,922			1,823			99
Total liabilities		28,629			37,153			(8,524	)
Stockholders' Equity:
Accumulated deficit		(123,993	)		(127,616	)		3,623
Total stockholders' equity		41,538			37,915			3,623
Total liabilities and stockholders' equity	$	70,167		$	75,068		$	(4,901	)

Contract with Customer, Asset and Liability [Table Text Block]

(In thousands)
Current contract liabilities - January 1, 2018	$	4,661
Long-term contract liabilities - January 1, 2018 (1)		84
Total contract liabilities - January 1, 2018	$	4,745
Total contract liabilities - January 1, 2018	$	4,745
Contract additions, net		2,168
Revenue recognized		(4,356	)
Translation		(202	)
Total contract liabilities - December 31, 2018	$	2,355
Current contract liabilities - December 31, 2018	$	2,226
Long-term contract liabilities - December 31, 2018 (1)		129
Total contract liabilities - December 31, 2018	$	2,355

Disaggregation of Revenue [Table Text Block]

(In thousands)	Power and Electromechanical		Energy		Total
Distributor sales	$	43,795	$	—	$	43,795
Direct Sales		32,652		20,342		52,994
Total revenues	$	76,447	$	20,342	$	96,789

(In thousands)	Power and Electromechanical		Energy		Total
Revenues recognized at point in time	$	76,447	$	4,391	$	80,838
Revenues recognized over time		—		15,951		15,951
Total revenues	$	76,447	$	20,342	$	96,789

(In thousands)	Power and Electromechanical		Energy		Total
North America	$	58,006	$	4,311	$	62,317
Europe		4,195		15,620		19,815
Asia		13,727		205		13,932
Other		519		206		725
Total revenues	$	76,447	$	20,342	$	96,789

Schedule of Antidilutive Securities Excluded from Computation of Earnings Per Share [Table Text Block]

	As of December 31,
	2018		2017		2016
Options, outstanding		923,898		964,180		966,681

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

	For the Years Ended December 31,
(In thousands, except share and per share amounts)	2018			2017			2016
Net loss	$	(17,325	)	$	(12,589	)	$	(7,266	)
Basic and diluted weighted average number of shares outstanding		28,517,339			22,397,865			20,897,812
Basic loss per common share	$	(0.61	)	$	(0.56	)	$	(0.35	)
Diluted loss per common share	$	(0.61	)	$	(0.56	)	$	(0.35	)

Schedule of Segment Reporting Information, by Segment [Table Text Block]

(In thousands)	Power and Electro- mechanical		Energy			Other			Total
Revenues from external customers	$	76,447	$	20,342		$	—		$	96,789
Depreciation and amortization (1)		1,480		1,525			—			3,005
Interest expense		221		23			258			502
Impairment of goodwill and other intangible assets		—		4,347			—			4,347
Income (loss) from operations		5,332		(17,168	)		(4,942	)		(16,778	)
Segment assets		45,553		19,034			5,580			70,167
Other intangibles assets, net		8,547		5,314			—			13,861
Goodwill		13,089		—			—			13,089
Expenditures for segment assets (2)		1,299		235			—			1,534

(In thousands)	Power and Electro- mechanical		Energy			Other			Total
Revenues from external customers	$	64,432	$	18,843		$	—		$	83,275
Depreciation and amortization (1)		1,505		1,345			—			2,850
Interest expense		249		1			250			500
Impairment of goodwill and other intangible assets		3		3,152			—			3,155
Income (loss) from operations		2,355		(11,366	)		(4,918	)		(13,929	)
Segment assets		49,392		26,512			12,005			87,909
Other intangibles assets, net		8,899		6,669			—			15,568
Goodwill		13,092		4,549			—			17,641
Expenditures for segment assets (2)		955		576			—			1,531

(In thousands)	Power and Electro- mechanical		Energy			Other			Total
Revenues from external customers	$	58,403	$	28,058		$	—		$	86,461
Depreciation and amortization (1)		1,445		1,401			2			2,848
Interest expense		221		6			240			467
Income (loss) from operations		645		(1,676	)		(5,479	)		(6,510	)
Segment assets		49,830		29,632			381			79,843
Other intangibles assets, net		9,262		6,939			—			16,201
Goodwill		13,083		7,042			—			20,125
Expenditures for segment assets (2)		1,032		642			—			1,674

Revenue from External Customers by Geographic Areas [Table Text Block]

	For the Years Ended December 31,
(In thousands)	2018					2017					2016
	Amount		%			Amount		%			Amount		%
USA	$	59,319		61	%	$	50,875		61	%	$	46,514		54	%
United Kingdom		15,185		16	%		14,522		17	%		17,337		20	%
China		5,463		6	%		5,381		7	%		5,930		7	%
All Others		16,822		17	%		12,497		15	%		16,680		19	%
Total	$	96,789		100	%	$	83,275		100	%	$	86,461		100	%

Long-lived Assets by Geographic Areas [Table Text Block]

	As of December 31,
(In thousands)	2018		2017
USA	$	23,544	$	27,662
United Kingdom		9,647		17,739
Other		1,495		1,232
	$	34,686	$	46,633