Restructuring Costs - Summary of Company's Net Pre-tax Restructuring Charges (Detail) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	$ 19.5	$ 7.1	$ 78.3	$ 19.7
Connectivity [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	3.1	(0.4)	13.8	6.6
Mobility [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	1.2	$ 7.5	8.9	$ 13.1
CPE [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	6.8		21.9
N&C [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	5.5		26.9
Ruckus [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring costs, net	$ 2.9		$ 6.8