SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES - Summary of Segment Activity (Detail) - USD ($) $ in Thousands		3 Months Ended													9 Months Ended	12 Months Ended
		Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	[1]	Dec. 31, 2015		Sep. 30, 2015		Jun. 30, 2015		Mar. 31, 2015	[1]	Sep. 30, 2015	Dec. 31, 2016	Dec. 31, 2015	Dec. 31, 2014
Segment Reporting Information [Line Items]
Revenues from external customers		$ 19,403	$ 23,257	$ 23,140	$ 20,661		$ 21,886	[2]	$ 24,845	[2]	$ 22,872	[2]	$ 16,637	[2]		$ 86,461	$ 86,240	$ 76,045
Depreciation and amortization	[3]															2,366	2,862	4,197
Earnings on equity method investment															$ 53	0	53	49
Interest expense																467	441	508
Income (loss) from operations		(2,564)	$ (585)	$ (1,037)	$ (2,324)		(1,068)		$ 167		$ (815)		$ (3,978)			(6,510)	(5,694)	(2,896)
Segment assets		79,843					90,848									79,843	90,848	93,054
Other intangibles assets, net		16,201					18,746									16,201	18,746	19,785
Goodwill		20,125					21,527									20,125	21,527	21,887
Expenditures for segment assets	[4]															1,674	5,173	1,182
Power and Electro-Mechanical Segment
Segment Reporting Information [Line Items]
Revenues from external customers																58,403	58,037	48,675
Depreciation and amortization	[3]															1,445	1,258	941
Earnings on equity method investment																	53	49
Interest expense																221	226	232
Income (loss) from operations																645	2,856	4,577
Segment assets		49,830					51,600									49,830	51,600	44,127
Other intangibles assets, net		9,262					9,577									9,262	9,577	8,482
Goodwill		13,083					13,077									13,083	13,077	13,021
Expenditures for segment assets	[4]															1,032	859	913
Energy Segment
Segment Reporting Information [Line Items]
Revenues from external customers																28,058	28,203	27,370
Depreciation and amortization	[3]															1,401	1,945	3,498
Earnings on equity method investment																	0	0
Interest expense																6	4	11
Income (loss) from operations																(1,676)	(3,915)	(3,501)
Segment assets		29,632					37,029									29,632	37,029	35,010
Other intangibles assets, net		6,939					9,167									6,939	9,167	11,295
Goodwill		7,042					8,450									7,042	8,450	8,866
Expenditures for segment assets	[4]															642	4,314	269
Other Segment
Segment Reporting Information [Line Items]
Revenues from external customers																0	0	0
Depreciation and amortization	[3]															2	6	3
Earnings on equity method investment																	0	0
Interest expense																240	211	265
Income (loss) from operations																(5,479)	(4,635)	(3,972)
Segment assets		381					2,219									381	2,219	13,917
Other intangibles assets, net		0					2									0	2	8
Goodwill		$ 0					$ 0									0	0	0
Expenditures for segment assets	[4]															$ 0	$ 0	$ 0

[1] On March 5, 2015, the Company closed on an Asset Purchase Agreement to acquire certain assets and assume certain liabilities of Tectrol, Inc., a Toronto, Canada corporation. The acquisition was effective March 1, 2015 and results are included from that date in the Company’s Power and Electromechanical segment.

[2] Revenue and cost of revenue have been revised. Immaterial revisions made to 2015 amounts were related to sales of raw material components to a vendor that in turn, sold finished goods inventory to the Company that included the raw material components that we had sold to the vendor. Revisions decreased total revenue and total cost of revenue for the first, second third and fourth quarters of 2015 by $216 thousand, $100 thousand, $83 thousand and $28 thousand, respectively. These revisions had no effect on gross profit, operating (loss) or net (loss). For more information see Note 2. Summary of Significant Accounting Policies - Revisions.

[3] For the years ended December 31, 2016, 2015 and 2014, depreciation and amortization totals included $0.5 million, $0.3 million and $0.2 million, respectively that were classified as cost of revenues in the Consolidated Statements of Operations.

[4] Includes purchases of property, plant and equipment and the investment in other intangible assets. Excludes amounts for the CUI – Canada, Inc. acquisition in 2015.