Segment Reporting - Segment Information About Reported Segment Product Revenues by Product Category (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Segment Reporting Information [Line Items]
Product revenues	$ 243,384	$ 259,540	$ 797,924	$ 624,214
Battery Performance Solutions (BPS)
Segment Reporting Information [Line Items]
Product revenues	16,928	15,956	52,265	33,818
Automotive Segments
Segment Reporting Information [Line Items]
Product revenues	233,028	249,764	767,503	590,622
Automotive Segments | Climate Control Seat (CCS)
Segment Reporting Information [Line Items]
Product revenues	89,991	97,058	297,393	229,465
Automotive Segments | Seat Heaters
Segment Reporting Information [Line Items]
Product revenues	61,516	73,471	208,101	171,345
Automotive Segments | Automotive Cables
Segment Reporting Information [Line Items]
Product revenues	19,465	18,917	66,686	50,890
Automotive Segments | Steering Wheel Heaters
Segment Reporting Information [Line Items]
Product revenues	24,578	22,506	80,139	49,721
Automotive Segments | Electronics
Segment Reporting Information [Line Items]
Product revenues	11,567	14,463	41,324	38,327
Automotive Segments | Other Automotive
Segment Reporting Information [Line Items]
Product revenues	8,983	7,393	21,595	17,056
Industrial Segments | Medical Segments
Segment Reporting Information [Line Items]
Product revenues	$ 10,356	$ 9,776	$ 30,421	$ 33,592