Goodwill and Intangible Assets, net - Changes in Goodwill (Details) $ in Millions	6 Months Ended
	Jun. 30, 2016 USD ($)
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	$ 928.5
Current year acquisitions (Note 2 – Business Acquisitions)	64.0
Foreign currency translation and prior year acquisitions	(3.3)
BALANCE JUNE 30, 2016	989.2
Electrical
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	611.2
Current year acquisitions (Note 2 – Business Acquisitions)	47.5
Foreign currency translation and prior year acquisitions	(4.4)
BALANCE JUNE 30, 2016	654.3
Power
Goodwill [Roll Forward]
BALANCE DECEMBER 31, 2015	317.3
Current year acquisitions (Note 2 – Business Acquisitions)	16.5
Foreign currency translation and prior year acquisitions	1.1
BALANCE JUNE 30, 2016	$ 334.9