Total Equity (Details) - USD ($) $ / shares in Units, $ in Millions	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	$ 2,240.7
Net income	181.5	$ 79.1
Other comprehensive (loss) income	5.4	$ (4.6)
Ending equity	$ 2,224.4
Cash dividends declared (USD per share)	$ 1.05	$ 0.98
Common Stock
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	$ 0.6	$ 0.6
Ending equity	0.6	0.6
Additional Paid-in Capital
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	0.0	4.9
Stock-based compensation	11.1	9.5
Acquisition/surrender of common shares	(11.2)	(14.0)
Directors deferred compensation	0.1	0.1
Ending equity	0.0	0.5
Retained Earnings
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	2,560.0	2,393.7
Net income	180.2	77.7
Acquisition/surrender of common shares	(145.2)	(2.7)
Cash dividends declared	(56.9)	(53.3)
Ending equity	2,538.1	2,415.4
Accumulated Other Comprehensive Income (Loss)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	(330.8)	(329.2)
Other comprehensive (loss) income	5.4	(4.6)
Ending equity	(325.4)	(333.8)
Total Hubbell Shareholders' Equity
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	2,229.8	2,070.0
Net income	180.2	77.7
Other comprehensive (loss) income	5.4	(4.6)
Stock-based compensation	11.1	9.5
Acquisition/surrender of common shares	(156.4)	(16.7)
Cash dividends declared	(56.9)	(53.3)
Directors deferred compensation	0.1	0.1
Ending equity	2,213.3	2,082.7
Non- controlling interest
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Beginning equity	10.9	15.4
Net income	1.3	1.4
Dividends to noncontrolling interest	(1.1)	(1.5)
Ending equity	$ 11.1	$ 15.3