Equity I (Details) (USD $) In Millions, unless otherwise specified	Sep. 30, 2012	Dec. 31, 2011	Sep. 30, 2011	Dec. 31, 2010
Equity [Line Items]
Common stock par value	$ 0.6	$ 0.6
Additional Paid In Capital	75.7	101.8
Retained Earnings	1,670.6	1,515.8
Accumulated Other Comprehensive Loss [Abstract]
Pension and post retirement benefit plan adjustment, net of tax	(145.8)	(153.7)
Cumulative translation adjustment	11.4	2.5
Unrealized gain on investment, net of tax	0.8	1.0
Cash flow hedge loss, net of tax	(0.8)	(0.2)
Total Accumulated Other Comprehensive Loss	(134.4)	(150.4)
Hubbell Shareholders' Equity	1,612.5	1,467.8
Noncontrolling interest	6.1	5.7
Total Equity	1,618.6	1,473.5	1,482.5	1,463.5
Class A Common Stock
Equity [Line Items]
Common stock par value	0.1	0.1
Class B Common Stock
Equity [Line Items]
Common stock par value	$ 0.5	$ 0.5