Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Earnings Per Share [Abstract]
NET INCOME ATTRIBUTABLE TO HUBBELL	$ 101.9	$ 130.7	$ 96.0	$ 72.3	$ 88.0	$ 113.6	$ 100.3	$ 58.3	$ 400.9	$ 360.2	$ 243.1
Less: Earnings allocated to participating securities									(1.5)	(1.3)	(0.8)
Net income available to common shareholders									$ 399.4	$ 358.9	$ 242.3
Average number of common shares outstanding (shares)									54.4	54.6	54.8
Potential dilutive shares (shares)									0.3	0.3	0.3
Average number of diluted shares outstanding (shares)									54.7	54.9	55.1
Basic (USD per share)	$ 1.87	$ 2.40	$ 1.76	$ 1.32	$ 1.61	$ 2.07	$ 1.83	$ 1.06	$ 7.35	$ 6.57	$ 4.42
Diluted (USD per share)	$ 1.85	$ 2.38	$ 1.75	$ 1.32	$ 1.60	$ 2.06	$ 1.82	$ 1.05	$ 7.31	$ 6.54	$ 4.39