Segment Information about Reported Product Revenues, Depreciation and Amortization and Operating Income (Loss) (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Segment Reporting Information [Line Items]
Product revenues	$ 213,441	$ 206,182	$ 420,350	$ 400,120
Depreciation and amortization	7,864	8,458	15,323	15,931
Operating income (loss)	26,670	24,514	53,747	49,552
Operating Segments | Automotive Segments
Segment Reporting Information [Line Items]
Product revenues	200,954	198,008	400,397	391,946
Depreciation and amortization	6,885	6,918	13,201	13,400
Operating income (loss)	42,070	38,525	82,752	73,699
Operating Segments | Industrial Segments
Segment Reporting Information [Line Items]
Product revenues	12,487	8,174	19,953	8,174
Depreciation and amortization	404	664	893	771
Operating income (loss)	(1,806)	(3,051)	(2,912)	(4,601)
Reconciling Items
Segment Reporting Information [Line Items]
Depreciation and amortization	575	876	1,229	1,760
Operating income (loss)	$ (13,594)	$ (10,960)	$ (26,093)	$ (19,546)