Earnings Per Share (Details) - USD ($) $ / shares in Units, shares in Millions, $ in Millions	3 Months Ended		6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2021	Jun. 30, 2020
Numerator:
Net income attributable to Hubbell Incorporated	$ 95.8	$ 88.2	$ 173.5	$ 163.2
Less: Earnings allocated to participating securities	(0.3)	(0.3)	(0.6)	(0.6)
Net income available to common shareholders	$ 95.5	$ 87.9	$ 172.9	$ 162.6
Denominator:
Average number of common shares outstanding (in shares)	54.3	54.1	54.3	54.2
Potential dilutive common shares (in shares)	0.4	0.2	0.4	0.2
Average number of diluted shares outstanding (in shares)	54.7	54.3	54.7	54.4
Earnings per share:
Basic (USD per share)	$ 1.76	$ 1.62	$ 3.19	$ 3.00
Diluted (USD per share)	$ 1.74	$ 1.62	$ 3.16	$ 2.99