Percentage of Total Product Revenues Generated from Customers (Detail)	12 Months Ended
	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Johnson Controls Inc.
Segment Reporting Information [Line Items]
Percentage of total product revenues generated from customer	24.00%	27.00%	22.00%
Lear Corporation
Segment Reporting Information [Line Items]
Percentage of total product revenues generated from customer	21.00%	18.00%	18.00%
Bosch
Segment Reporting Information [Line Items]
Percentage of total product revenues generated from customer	9.00%	10.00%	10.00%