Quarterly Financial Data (Unaudited) (Details) - USD ($) $ / shares in Units, $ 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
Quarterly Financial Information Disclosure [Abstract]
Net sales	$ 1,037.9	$ 1,108.6	$ 949.2	$ 1,090.3	$ 1,103.3	$ 1,204.0	$ 1,196.4	$ 1,087.3	$ 4,186.0	$ 4,591.0	$ 4,481.7
Cost of goods sold	752.2	779.0	668.7	776.8	777.3	842.0	839.0	780.0	2,976.7	3,238.3	3,181.3
Gross profit	285.7	329.6	280.5	313.5	326.0	362.0	357.4	307.3	1,209.3	1,352.7	1,300.4
Selling & administrative expenses	165.9	166.7	149.0	194.7	190.1	189.1	190.5	186.4	676.3	756.1	743.5
Net income	82.6	108.6	89.1	75.7	103.1	132.6	97.9	73.8	356.0	407.4	366.1
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
Earning 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
Earning Per Share - 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