Goodwill and Intangible Assets, net - Changes in Goodwill (Details) $ in Millions	9 Months Ended
	Sep. 30, 2016 USD ($)
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	$ 928.5
Current year acquisitions (Note 2 – Business Acquisitions)	66.9
Foreign currency translation and prior year acquisitions	(3.4)
BALANCE SEPTEMBER 30, 2016	992.0
Electrical
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	611.2
Current year acquisitions (Note 2 – Business Acquisitions)	48.4
Foreign currency translation and prior year acquisitions	(4.7)
BALANCE SEPTEMBER 30, 2016	654.9
Power
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	317.3
Current year acquisitions (Note 2 – Business Acquisitions)	18.5
Foreign currency translation and prior year acquisitions	1.3
BALANCE SEPTEMBER 30, 2016	$ 337.1