Segment Information about Reported Product Revenues and Operating Income (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Segment Reporting Information [Line Items]
Product revenues	$ 206,182	$ 160,520	$ 400,120	$ 308,610
Depreciation and amortization	8,458	7,796	15,931	15,730
Operating income (loss)	24,235	8,419	49,051	18,210
Automotive
Segment Reporting Information [Line Items]
Product revenues	198,008	160,520	391,946	308,610
Depreciation and amortization	7,073	7,322	13,728	14,754
Operating income (loss)	38,237	22,037	76,016	43,686
Industrial
Segment Reporting Information [Line Items]
Product revenues	8,174		8,174
Depreciation and amortization	773	92	950	225
Operating income (loss)	(2,144)	(2,374)	(3,857)	(4,631)
Reconciling Items
Segment Reporting Information [Line Items]
Depreciation and amortization	612	382	1,253	751
Operating income (loss)	$ (11,858)	$ (11,244)	$ (23,108)	$ (20,845)