Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended
	Mar. 31, 2021	Mar. 31, 2020
Numerator:
Net income attributable to Hubbell Incorporated	$ 77.7	$ 75.0
Less: Earnings allocated to participating securities	(0.3)	(0.3)
Net income available to common shareholders	$ 77.4	$ 74.7
Denominator:
Average number of common shares outstanding (in shares)	54.2	54.3
Potential dilutive common shares (in shares)	0.5	0.3
Average number of diluted shares outstanding (in shares)	54.7	54.6
Basic (USD per share)	$ 1.43	$ 1.38
Diluted (USD per share)	$ 1.42	$ 1.37