Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2017 USD ($)	Jun. 30, 2016 USD ($)	Jun. 30, 2017 USD ($) group	Jun. 30, 2016 USD ($)
Segment Reporting Information [Line Items]
Net sales	$ 948.3	$ 908.8	$ 1,800.6	$ 1,743.6
Operating Income	$ 130.6	$ 132.1	$ 234.7	$ 234.0
Operating Income as a % of Net Sales	13.80%	14.50%	13.00%	13.40%
Electrical
Segment Reporting Information [Line Items]
Number of business groups (in groups) | group			3
Net sales	$ 656.4	$ 641.4	$ 1,243.9	$ 1,224.1
Operating Income	$ 71.0	$ 77.1	$ 121.0	$ 132.5
Operating Income as a % of Net Sales	10.80%	12.00%	9.70%	10.80%
Power
Segment Reporting Information [Line Items]
Net sales	$ 291.9	$ 267.4	$ 556.7	$ 519.5
Operating Income	$ 59.6	$ 55.0	$ 113.7	$ 101.5
Operating Income as a % of Net Sales	20.40%	20.60%	20.40%	19.50%