Total Equity I (Details) - USD ($) $ / shares in Units, $ in Millions	6 Months Ended
	Jun. 30, 2017	Dec. 31, 2016	Jun. 30, 2016	Dec. 31, 2015
Class of Stock [Line Items]
Common Stock-- authorized 200.0 shares; issued and outstanding 54.7 and 55.5 shares	$ 0.5	$ 0.6
Additional paid-in capital	0.0	15.4
Retained earnings	1,871.8	1,879.3
Accumulated other comprehensive loss:
Pension and post retirement benefit plan adjustment, net of tax	(176.8)	(180.5)
Cumulative translation adjustment	(101.6)	(120.8)
Unrealized gain on investment, net of tax	(0.7)	(1.2)
Cash flow hedge (loss) gain, net of tax	(0.9)	0.0
Total Accumulated other comprehensive loss	(280.0)	(302.5)
Hubbell shareholders’ equity	1,592.3	1,592.8
Noncontrolling interest	10.9	10.4
Total Equity	$ 1,603.2	$ 1,603.2	$ 1,579.4	$ 1,749.0
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)	54,700,000	55,500,000
Common stock, shares, outstanding (in shares)	54,700,000	55,500,000
Retained Earnings
Accumulated other comprehensive loss:
Stock repurchased and retired during period	$ 72.1