Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended								12 Months Ended
	Dec. 31, 2020	Sep. 30, 2020	Jun. 30, 2020	Mar. 31, 2020	Dec. 31, 2019	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Numerator:
Net income attributable to Hubbell Incorporated	$ 80.9	$ 107.1	$ 88.2	$ 75.0	$ 101.9	$ 130.7	$ 96.0	$ 72.3	$ 351.2	$ 400.9	$ 360.2
Less: Earnings allocated to participating securities									(1.3)	(1.5)	(1.3)
Net income available to common shareholders									$ 349.9	$ 399.4	$ 358.9
Denominator:
Average number of common shares outstanding (shares)									54.2	54.4	54.6
Potential dilutive shares (shares)									0.3	0.3	0.3
Average number of diluted shares outstanding (shares)									54.5	54.7	54.9
Earnings per share:
Basic (USD per share)	$ 1.49	$ 1.97	$ 1.62	$ 1.38	$ 1.87	$ 2.40	$ 1.76	$ 1.32	$ 6.46	$ 7.35	$ 6.57
Diluted (USD per share)	$ 1.48	$ 1.96	$ 1.62	$ 1.37	$ 1.85	$ 2.38	$ 1.75	$ 1.32	$ 6.43	$ 7.31	$ 6.54