Segment Information (Details) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018 USD ($)	Sep. 30, 2017 USD ($)	Sep. 30, 2018 USD ($) group	Sep. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Total net sales	$ 1,179.7	$ 950.5	$ 3,337.6	$ 2,751.1
Operating Income	$ 163.8	$ 150.1	$ 420.3	$ 392.3
Operating Income as a % of Net Sales	13.90%	15.80%	12.60%	14.30%
Electrical
Segment Reporting Information [Line Items]
Number of business groups (in groups) | group			3
Total net sales	$ 687.4	$ 654.0	$ 1,994.1	$ 1,897.9
Operating Income	$ 94.0	$ 88.4	$ 246.5	$ 215.2
Operating Income as a % of Net Sales	13.70%	13.50%	12.40%	11.30%
Power
Segment Reporting Information [Line Items]
Total net sales	$ 492.3	$ 296.5	$ 1,343.5	$ 853.2
Operating Income	$ 69.8	$ 61.7	$ 173.8	$ 177.1
Operating Income as a % of Net Sales	14.20%	20.80%	12.90%	20.80%