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Note 4 - Goodwill and Other Intangible Assets - Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended	12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Sep. 30, 2019	Dec. 31, 2019	Dec. 31, 2018	Oct. 01, 2019	Jan. 01, 2018
Goodwill, gross	$ 21,993	$ 148,260	$ 148,260	$ 21,993	$ 148,408	$ 10,778	$ 148,768
Accumulated impairment charges		(137,482)	(137,482)		(128,591)		(128,591)
Goodwill	21,993	10,778	10,778	21,993	19,817	10,778	20,177
Goodwill allocation related to acquisition	10,287				1,290
Foreign currency translation	928		(122)		(1,650)
Impairment charge			(8,891)	0	0
Measurement period adjustment			(26)
Goodwill, gross (reallocation)	21,993	148,260	148,260	21,993	148,408	10,778	148,768
Cinch Connectivity Solutions Segment [Member]
Goodwill, gross	7,179			7,179		6,467
Goodwill	7,179			7,179		6,467
Goodwill allocation related to acquisition
Foreign currency translation	712
Goodwill, gross (reallocation)	7,179			7,179		6,467
Power Solutions and Protection Segment [Member]
Goodwill, gross	14,814			14,814		4,311
Goodwill	14,814			14,814		4,311
Goodwill allocation related to acquisition	10,287
Foreign currency translation	216
Goodwill, gross (reallocation)	14,814			14,814		4,311
Magnetic Solutions Segment [Member]
Goodwill, gross
Goodwill
Goodwill allocation related to acquisition
Foreign currency translation
Goodwill, gross (reallocation)
North America [Member]
Goodwill, gross		63,364	63,364		63,364		63,364
Accumulated impairment charges		(63,364)	(63,364)		(54,473)		(54,474)
Goodwill					8,891		8,890
Goodwill allocation related to acquisition
Foreign currency translation
Impairment charge		(8,900)	(8,891)
Measurement period adjustment
Goodwill, gross (reallocation)		63,364	63,364		63,364		63,364
Asia [Member]
Goodwill, gross		54,508	54,508		54,508		54,508
Accumulated impairment charges		(54,508)	(54,508)		(54,508)		(54,508)
Goodwill
Goodwill allocation related to acquisition
Foreign currency translation
Impairment charge
Measurement period adjustment
Goodwill, gross (reallocation)		54,508	54,508		54,508		54,508
Europe [Member]
Goodwill, gross		30,388	30,388		30,536		30,896
Accumulated impairment charges		(19,610)	(19,610)		(19,610)		(19,609)
Goodwill		10,778	10,778		10,926		11,287
Goodwill allocation related to acquisition					1,290
Foreign currency translation			(122)		(1,650)
Impairment charge	$ 0
Measurement period adjustment			(26)
Goodwill, gross (reallocation)		$ 30,388	$ 30,388		$ 30,536		$ 30,896