Revenue - Disaggregation of Revenue (Details) - USD ($) $ in Millions	3 Months Ended		9 Months Ended
	Sep. 30, 2018	Sep. 30, 2017	Sep. 30, 2018	Sep. 30, 2017
Disaggregation of Revenue [Line Items]
Total net sales	$ 1,179.7	$ 950.5	$ 3,337.6	$ 2,751.1
United States
Disaggregation of Revenue [Line Items]
Total net sales	1,063.3		3,012.5
International
Disaggregation of Revenue [Line Items]
Total net sales	116.4		325.1
Hubbell Commercial and Industrial
Disaggregation of Revenue [Line Items]
Total net sales	234.2		685.0
Hubbell Construction and Energy
Disaggregation of Revenue [Line Items]
Total net sales	204.9		598.7
Hubbell Lighting
Disaggregation of Revenue [Line Items]
Total net sales	248.3		710.4
Hubbell Power Systems
Disaggregation of Revenue [Line Items]
Total net sales	492.3		1,343.5
Electrical
Disaggregation of Revenue [Line Items]
Total net sales	687.4	654.0	1,994.1	1,897.9
Electrical | United States
Disaggregation of Revenue [Line Items]
Total net sales	615.3		1,776.1
Electrical | International
Disaggregation of Revenue [Line Items]
Total net sales	72.1		218.0
Electrical | Hubbell Commercial and Industrial
Disaggregation of Revenue [Line Items]
Total net sales	234.2		685.0
Electrical | Hubbell Construction and Energy
Disaggregation of Revenue [Line Items]
Total net sales	204.9		598.7
Electrical | Hubbell Lighting
Disaggregation of Revenue [Line Items]
Total net sales	248.3		710.4
Electrical | Hubbell Power Systems
Disaggregation of Revenue [Line Items]
Total net sales	0.0		0.0
Power
Disaggregation of Revenue [Line Items]
Total net sales	492.3	$ 296.5	1,343.5	$ 853.2
Power | United States
Disaggregation of Revenue [Line Items]
Total net sales	448.0		1,236.4
Power | International
Disaggregation of Revenue [Line Items]
Total net sales	44.3		107.1
Power | Hubbell Commercial and Industrial
Disaggregation of Revenue [Line Items]
Total net sales	0.0		0.0
Power | Hubbell Construction and Energy
Disaggregation of Revenue [Line Items]
Total net sales	0.0		0.0
Power | Hubbell Lighting
Disaggregation of Revenue [Line Items]
Total net sales	0.0		0.0
Power | Hubbell Power Systems
Disaggregation of Revenue [Line Items]
Total net sales	$ 492.3		$ 1,343.5