Net Sales by Product (Detail) - USD ($) $ in Millions		12 Months Ended
		Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Net sales		$ 8,678.2	$ 8,136.8	$ 7,921.6
Airbag Products
Segment Reporting Information [Line Items]
Net sales	[1]	5,698.6	5,343.2	5,256.4
Seatbelt Products
Segment Reporting Information [Line Items]
Net sales	[1]	$ 2,979.6	$ 2,793.6	$ 2,665.2

[1] Including Corporate and other sales