Revenue from Contracts with Customers Summary of Sales to External Customer by Operating Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Disaggregation of Revenue [Line Items]
Net sales	$ 427,534	$ 489,514	$ 524,194
United States and Puerto Rico
Disaggregation of Revenue [Line Items]
Net sales	268,551	319,055	343,914
China
Disaggregation of Revenue [Line Items]
Net sales	52,005	45,515	49,147
Brazil
Disaggregation of Revenue [Line Items]
Net sales	27,744	36,358	35,529
Mexico
Disaggregation of Revenue [Line Items]
Net sales	29,865	32,304	39,307
Germany
Disaggregation of Revenue [Line Items]
Net sales	6,224	6,437	5,678
Poland
Disaggregation of Revenue [Line Items]
Net sales	4,927	6,378	7,023
Other
Disaggregation of Revenue [Line Items]
Net sales	38,218	43,467	43,596
Operating Segments | Mobile Solutions
Disaggregation of Revenue [Line Items]
Net sales	256,360	297,749	335,037
Operating Segments | Mobile Solutions | United States and Puerto Rico
Disaggregation of Revenue [Line Items]
Net sales	129,147	162,445	187,178
Operating Segments | Mobile Solutions | China
Disaggregation of Revenue [Line Items]
Net sales	46,442	38,793	43,610
Operating Segments | Mobile Solutions | Brazil
Disaggregation of Revenue [Line Items]
Net sales	27,055	36,058	35,314
Operating Segments | Mobile Solutions | Mexico
Disaggregation of Revenue [Line Items]
Net sales	16,465	18,815	27,053
Operating Segments | Mobile Solutions | Germany
Disaggregation of Revenue [Line Items]
Net sales	5,846	6,372	5,652
Operating Segments | Mobile Solutions | Poland
Disaggregation of Revenue [Line Items]
Net sales	4,913	6,363	7,010
Operating Segments | Mobile Solutions | Other
Disaggregation of Revenue [Line Items]
Net sales	26,492	28,903	29,220
Operating Segments | Power Solutions
Disaggregation of Revenue [Line Items]
Net sales	171,269	192,100	189,778
Operating Segments | Power Solutions | United States and Puerto Rico
Disaggregation of Revenue [Line Items]
Net sales	139,499	156,945	157,357
Operating Segments | Power Solutions | China
Disaggregation of Revenue [Line Items]
Net sales	5,563	6,722	5,537
Operating Segments | Power Solutions | Brazil
Disaggregation of Revenue [Line Items]
Net sales	689	300	215
Operating Segments | Power Solutions | Mexico
Disaggregation of Revenue [Line Items]
Net sales	13,400	13,489	12,254
Operating Segments | Power Solutions | Germany
Disaggregation of Revenue [Line Items]
Net sales	378	65	26
Operating Segments | Power Solutions | Poland
Disaggregation of Revenue [Line Items]
Net sales	14	15	13
Operating Segments | Power Solutions | Other
Disaggregation of Revenue [Line Items]
Net sales	11,726	14,564	14,376
Intersegment Sales Eliminations
Disaggregation of Revenue [Line Items]
Net sales	(95)	(335)	(621)
Intersegment Sales Eliminations | United States and Puerto Rico
Disaggregation of Revenue [Line Items]
Net sales	(95)	(335)	(621)
Intersegment Sales Eliminations | China
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Intersegment Sales Eliminations | Brazil
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Intersegment Sales Eliminations | Mexico
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Intersegment Sales Eliminations | Germany
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Intersegment Sales Eliminations | Poland
Disaggregation of Revenue [Line Items]
Net sales	0	0	0
Intersegment Sales Eliminations | Other
Disaggregation of Revenue [Line Items]
Net sales	$ 0	$ 0	$ 0