Segment Information About Reported Segment Product Revenues by Product Category (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Product revenues	$ 1,038,259	$ 985,683	$ 917,600
Total product revenues in percentage	100.00%	100.00%	100.00%
Automotive Segments
Segment Reporting Information [Line Items]
Product revenues	$ 948,592	$ 879,457	$ 847,428
Total product revenues in percentage	91.00%	89.00%	92.00%
Automotive Segments | Climate Control Seat (CCS)
Segment Reporting Information [Line Items]
Product revenues	$ 374,816	$ 387,961	$ 405,795
Total product revenues in percentage	36.00%	40.00%	44.00%
Automotive Segments | Seat Heaters
Segment Reporting Information [Line Items]
Product revenues	$ 305,337	$ 307,309	$ 288,939
Total product revenues in percentage	29.00%	31.00%	32.00%
Automotive Segments | Steering Wheel Heaters
Segment Reporting Information [Line Items]
Product revenues	$ 69,845	$ 62,125	$ 49,516
Total product revenues in percentage	7.00%	6.00%	5.00%
Automotive Segments | Automotive Cables
Segment Reporting Information [Line Items]
Product revenues	$ 98,931	$ 92,093	$ 85,283
Total product revenues in percentage	9.00%	9.00%	9.00%
Automotive Segments | Battery Thermal Management (BTM)
Segment Reporting Information [Line Items]
Product revenues	$ 28,472	$ 10,043	$ 6,546
Total product revenues in percentage	3.00%	1.00%	1.00%
Automotive Segments | Etratech Inc.
Segment Reporting Information [Line Items]
Product revenues	$ 54,267	$ 8,398
Total product revenues in percentage	5.00%	1.00%	0.00%
Automotive Segments | Other Automotive
Segment Reporting Information [Line Items]
Product revenues	$ 16,924	$ 11,528	$ 11,349
Total product revenues in percentage	2.00%	1.00%	1.00%
Industrial Segments
Segment Reporting Information [Line Items]
Product revenues	$ 89,667	$ 106,226	$ 70,172
Total product revenues in percentage	9.00%	11.00%	8.00%
Industrial Segments | Remote Power Generation
Segment Reporting Information [Line Items]
Product revenues	$ 19,222	$ 31,891	$ 18,628
Total product revenues in percentage	2.00%	3.00%	2.00%
Industrial Segments | Cincinnati Sub-Zero Products (CSZ)
Segment Reporting Information [Line Items]
Product revenues	$ 70,445	$ 74,335	$ 51,544
Total product revenues in percentage	7.00%	8.00%	6.00%