Total Equity I (Details) - USD ($) $ / shares in Units, $ in Millions	Sep. 30, 2015	Dec. 31, 2014	Sep. 30, 2014	Dec. 31, 2013
Equity [Line Items]
Additional paid-in-capital	$ 79.4	$ 146.7
Retained earnings	2,062.5	1,944.1
Accumulated other comprehensive loss:
Pension and post retirement benefit plan adjustment, net of tax	(119.4)	(124.7)
Cumulative translation adjustment	(80.0)	(39.9)
Cumulative translation adjustment	0.2	0.3
Cash flow hedge gain, net of tax	0.6	0.0
Total Accumulated other comprehensive loss	(198.6)	(164.3)
Hubbell shareholders’ equity	1,943.9	1,927.1
Noncontrolling interest	9.7	8.6
Total Equity	$ 1,953.6	$ 1,935.7	$ 2,035.0	$ 1,914.8
Common stock par value per share (USD per share)	$ 0.01	$ 0.01
Class A Common Stock
Equity [Line Items]
Common stock par value	$ 0.1	$ 0.1
Accumulated other comprehensive loss:
Common stock, shares authorized (shares)	50,000,000	50,000,000
Common stock, shares, issued (shares)	7,200,000	7,200,000
Common stock, shares, outstanding (shares)	7,200,000	7,200,000
Class B Common Stock
Equity [Line Items]
Common stock par value	$ 0.5	$ 0.5
Accumulated other comprehensive loss:
Common stock par value per share (USD per share)	$ 0.01
Common stock, shares authorized (shares)	150,000,000	150,000,000
Common stock, shares, issued (shares)	50,700,000	51,300,000
Common stock, shares, outstanding (shares)	50,700,000	51,300,000