Segment Reporting - Segment Information About Reported Segment Product Revenues by Product Category (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Segment Reporting Information [Line Items]
Product revenues	$ 288,535	$ 228,613
Automotive Segments
Segment Reporting Information [Line Items]
Product revenues	279,370	216,472
Automotive Segments | Climate Control Seat (CCS)
Segment Reporting Information [Line Items]
Product revenues	109,173	82,528
Automotive Segments | Seat Heaters
Segment Reporting Information [Line Items]
Product revenues	76,721	64,532
Automotive Segments | Automotive Cables
Segment Reporting Information [Line Items]
Product revenues	24,281	22,140
Automotive Segments | Steering Wheel Heaters
Segment Reporting Information [Line Items]
Product revenues	28,864	19,235
Automotive Segments | Battery Performance Solutions (BPS)
Segment Reporting Information [Line Items]
Product revenues	17,760	11,209
Automotive Segments | Electronics
Segment Reporting Information [Line Items]
Product revenues	15,105	10,376
Automotive Segments | Other Automotive
Segment Reporting Information [Line Items]
Product revenues	7,466	6,452
Industrial Segments | Medical Segments
Segment Reporting Information [Line Items]
Product revenues	$ 9,165	$ 12,141