Segment Information (Details) $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2018 USD ($)	Jun. 30, 2017 USD ($)	Jun. 30, 2018 USD ($) group	Jun. 30, 2017 USD ($)
Segment Reporting Information [Line Items]
Total net sales	$ 1,166.7	$ 948.3	$ 2,157.9	$ 1,800.6
Operating Income	$ 156.9	$ 134.4	$ 256.5	$ 242.2
Operating Income as a % of Net Sales	13.40%	14.20%	11.90%	13.50%
Electrical
Segment Reporting Information [Line Items]
Number of business groups (in groups) | group			3
Total net sales	$ 688.6	$ 656.4	$ 1,306.7	$ 1,243.9
Operating Income	$ 91.3	$ 74.0	$ 152.5	$ 126.8
Operating Income as a % of Net Sales	13.30%	11.30%	11.70%	10.20%
Power
Segment Reporting Information [Line Items]
Total net sales	$ 478.1	$ 291.9	$ 851.2	$ 556.7
Operating Income	$ 65.6	$ 60.4	$ 104.0	$ 115.4
Operating Income as a % of Net Sales	13.70%	20.70%	12.20%	20.70%