Segment Information Sales Including Intersegment Sales (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2016	Sep. 30, 2015	Sep. 30, 2016	Sep. 30, 2015
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ 2,461.3	$ 2,184.5	$ 7,469.8	$ 6,650.1
Operating Segments
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	2,476.1	2,194.3	7,515.0	6,678.3
Operating Segments | Passive Safety
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1,898.7	1,797.2	5,883.5	5,552.9
Operating Segments | Electronics
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	577.4	397.1	1,631.5	1,125.4
Corporate and other
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	1.1	3.9	3.1	11.1
Intersegment Eliminations
Segment Reporting, Revenue Reconciling Item [Line Items]
Net sales	$ (15.9)	$ (13.7)	$ (48.3)	$ (39.3)