Segment Information Depreciation and Amortization (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Reconciliation of Depreciation by Segment [Line Items]
Depreciation and amortization	$ 104.2	$ 97.6	$ 318.6	$ 279.4
Passive Safety
Reconciliation of Depreciation by Segment [Line Items]
Depreciation and amortization	77.0	69.2	224.8	206.8
Electronics
Reconciliation of Depreciation by Segment [Line Items]
Depreciation and amortization	24.9	26.2	86.2	66.0
Corporate and other
Reconciliation of Depreciation by Segment [Line Items]
Depreciation and amortization	$ 2.3	$ 2.2	$ 7.6	$ 6.6