Reportable Business Segments (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) segment	Sep. 30, 2017 USD ($)
Segment reporting information
Number of reportable business segments | segment			2
Net sales	$ 2,129.0	$ 1,840.8	$ 5,977.3	$ 5,067.4
Segment operating income	444.2	377.9	1,229.3	1,028.2
Interconnect Products and Assemblies
Segment reporting information
Net sales	2,019.3		5,659.5
Cable Products and Solutions
Segment reporting information
Net sales	109.7		317.8
Operating Segment
Segment reporting information
Net sales	2,129.0	1,840.8	5,977.3	5,067.4
Segment operating income	472.5	402.6	1,309.3	1,104.8
Operating Segment | Interconnect Products and Assemblies
Segment reporting information
Net sales	2,019.3	1,731.5	5,659.5	4,754.3
Segment operating income	458.1	388.3	1,268.9	1,060.8
Operating Segment | Cable Products and Solutions
Segment reporting information
Net sales	109.7	109.3	317.8	313.1
Segment operating income	14.4	14.3	40.4	44.0
Inter-Segment
Segment reporting information
Net sales	11.9	13.6	34.7	38.4
Inter-Segment | Interconnect Products and Assemblies
Segment reporting information
Net sales	3.8	2.7	9.6	6.9
Inter-Segment | Cable Products and Solutions
Segment reporting information
Net sales	$ 8.1	$ 10.9	$ 25.1	$ 31.5