Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2016	Jun. 30, 2016	Mar. 31, 2016	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Earnings Per Share [Abstract]
Net Income attributable to Hubbell	$ 20.4	$ 80.8	$ 79.1	$ 62.8	$ 64.4	$ 86.7	$ 81.0	$ 60.9	$ 243.1	$ 293.0	$ 277.3
Less: Earnings allocated to participating securities									(0.8)	(0.9)	(0.7)
Net income available to common shareholders									$ 242.3	$ 292.1	$ 276.6
Average number of common shares outstanding									54.8	55.5	57.7
Potential dilutive shares									0.3	0.2	0.3
Average number of diluted shares outstanding (shares)									55.1	55.7	58.0
Basic (USD per share)	$ 0.37	$ 1.47	$ 1.44	$ 1.13	$ 1.16	$ 1.56	$ 1.46	$ 1.08	$ 4.42	$ 5.26	$ 4.79
Diluted (USD per share)	$ 0.37	$ 1.47	$ 1.43	$ 1.13	$ 1.16	$ 1.56	$ 1.45	$ 1.08	$ 4.39	$ 5.24	$ 4.77