Segment Information (Details) $ in Millions	3 Months Ended
	Mar. 31, 2017 USD ($) group	Mar. 31, 2016 USD ($)
Segment Reporting Information [Line Items]
Net sales	$ 852.3	$ 834.8
Operating Income	$ 104.1	$ 101.9
Operating Income as a % of Net Sales	12.20%	12.20%
Electrical
Segment Reporting Information [Line Items]
Number of business groups (in groups) | group	3
Net sales	$ 587.5	$ 582.7
Operating Income	$ 50.0	$ 55.4
Operating Income as a % of Net Sales	8.50%	9.50%
Power
Segment Reporting Information [Line Items]
Net sales	$ 264.8	$ 252.1
Operating Income	$ 54.1	$ 46.5
Operating Income as a % of Net Sales	20.40%	18.40%