SEGMENTS, Entity Wide Information (Details) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2017 USD ($)	Sep. 30, 2017 USD ($)	Jun. 30, 2017 USD ($)	Mar. 31, 2017 USD ($)	Dec. 31, 2016 USD ($)	Sep. 30, 2016 USD ($)	Jun. 30, 2016 USD ($)	Mar. 31, 2016 USD ($)	Dec. 31, 2017 USD ($) Customer	Dec. 31, 2016 USD ($) Customer	Dec. 31, 2015 USD ($) Customer
Segment Reporting Information [Line Items]
Net sales to external customers									$ 491,611	$ 500,153	$ 567,080	[1]
Long-Lived Assets	$ 71,468				$ 75,109				71,468	75,109
Net sales to external customers	119,940	$ 126,386	$ 131,617	$ 113,668	118,539	$ 128,809	$ 131,622	$ 121,182	$ 491,611	$ 500,153	$ 567,080	[1]
Net Sales [Member] | Customer Concentration Risk [Member]
Segment Reporting Information [Line Items]
Number of customers representing sales in excess of ten percent | Customer									1	1	1
Net sales to external customers									$ 57,700	$ 59,800	$ 74,800
Concentration risk percentage									11.70%	12.00%	13.20%
Connectivity Solutions [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									$ 170,337	$ 168,845	$ 181,697
Magnetic Solutions [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									161,011	155,232	166,182
Power Solutions and Protection [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									$ 160,263	176,076	219,201
Asia [Member] | Geographic Concentration Risk [Member]
Segment Reporting Information [Line Items]
Concentration risk percentage									36.90%
United States [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									$ 245,834	256,760	304,328
Long-Lived Assets	27,594				29,740				27,594	29,740
People's Republic of China (PRC) [Member]
Segment Reporting Information [Line Items]
Long-Lived Assets	30,151				32,666				30,151	32,666
Macao [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									167,681	163,971	182,248
United Kingdom [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									24,110	21,953	27,552
Long-Lived Assets	1,345				1,419				1,345	1,419
Switzerland [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									15,366	14,048	18,050
Long-Lived Assets	3,632				3,593				3,632	3,593
Slovakia [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									14,194	17,622	2,807
Long-Lived Assets	7,625				6,574				7,625	6,574
Germany [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									13,857	14,104	16,314
All Other Foreign Countries [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									10,569	11,695	15,781
Long-Lived Assets	$ 1,121				$ 1,117				1,121	1,117
Reportable Operating Segments [Member] | North America [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									245,834	256,760	304,328	[1]
Net sales to external customers									257,541	268,935	329,304	[1]
Reportable Operating Segments [Member] | Asia [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									167,680	168,458	188,146	[1]
Net sales to external customers									249,506	256,202	295,751	[1]
Reportable Operating Segments [Member] | Europe [Member]
Segment Reporting Information [Line Items]
Net sales to external customers									78,097	74,935	74,606	[1]
Net sales to external customers									$ 89,765	$ 86,750	$ 148,735	[1]

[1] (Revised)