Total Equity I (Details) - USD ($) $ / shares in Units, $ in Millions	9 Months Ended
	Sep. 30, 2016	Dec. 31, 2015	Sep. 30, 2015	Dec. 31, 2014
Class of Stock [Line Items]
Common Stock-- authorized 200.0 shares; issued and outstanding 55.4 and 57.8 shares	$ 0.6	$ 0.6
Additional paid-in capital	6.5	78.1
Retained earnings	1,853.7	1,886.1
Accumulated other comprehensive loss:
Pension and post retirement benefit plan adjustment, net of tax	(134.0)	(140.2)
Cumulative translation adjustment	(101.1)	(85.4)
Unrealized gain on investment, net of tax	0.3	0.0
Cash flow hedge (loss) gain, net of tax	(0.5)	1.4
Total Accumulated other comprehensive loss	(235.3)	(224.2)
Hubbell shareholders’ equity	1,625.5	1,740.6
Noncontrolling interest	9.1	8.4
Total Equity	$ 1,634.6	$ 1,749.0	$ 1,953.6	$ 1,935.7
Common stock par value per share (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	200,000,000.0	200,000,000.0
Common stock, shares, issued (in shares)	55,400,000	57,800,000
Common stock, shares, outstanding (in shares)	55,400,000	57,800,000
Retained Earnings
Accumulated other comprehensive loss:
Stock repurchased and retired during period	$ 155.5