Total Equity I (Details) - USD ($) $ / shares in Units, $ in Millions	Mar. 31, 2016	Dec. 31, 2015	Mar. 31, 2015	Dec. 31, 2014
Stockholders' Equity Note [Abstract]
Common Stock-- authorized 200.0 shares; issued and outstanding 55.7 and 57.8 shares	$ 0.6	$ 0.6
Additional paid-in capital	0.0	78.1
Retained earnings	1,789.8	1,886.1
Accumulated other comprehensive loss:
Pension and post retirement benefit plan adjustment, net of tax	(138.2)	(140.2)
Cumulative translation adjustment	(84.7)	(85.4)
Cumulative translation adjustment	0.3	0.0
Cash flow hedge (loss) gain, net of tax	(0.9)	1.4
Total Accumulated other comprehensive loss	(223.5)	(224.2)
Hubbell shareholders’ equity	1,566.9	1,740.6
Noncontrolling interest	8.8	8.4
Total Equity	$ 1,575.7	$ 1,749.0	$ 1,871.2	$ 1,935.7
Common stock par value per share (USD per share)	$ 0.01	$ 0.01
Common stock, shares authorized (shares)	200,000,000.0	200,000,000.0
Common stock, shares, issued (shares)	55,700,000	55,700,000
Common stock, shares, outstanding (shares)	57,800,000	57,800,000