Consolidating Financial Information - Consolidating Income Statements (Details) (USD $) In Millions	3 Months Ended				9 Months Ended		12 Months Ended
	Sep. 30, 2011	Sep. 30, 2010	Jun. 30, 2010	Sep. 30, 2008	Sep. 30, 2011	Sep. 30, 2010	Dec. 31, 2009
Consolidated Income Statements
Revenues	$ 1,389.7	$ 1,240.7			$ 4,036.3	$ 3,806.0
Cost of sales	931.2	821.6			2,682.0	2,537.7
Selling and administrative expenses	269.2	236.7			779.8	737.1
Equity in (income) of Apex Tool Group, LLC	(16.0)	(10.5)			(44.9)	(10.5)
Loss related to contribution of net assets to Apex Tool Group, LLC			134.5			134.5
Restructuring charges		1.5				8.0
Interest expense, net	16.4	12.3			49.8	36.2
Income (loss) before income taxes	188.9	179.1			569.6	363.0
Income tax expense (benefit)	28.7	37.4			92.2	61.1
Income from continuing operations	160.2	141.7			477.4	301.9
Income related to discontinued operations, net of income taxes				16.6	190.3		25.5
Net income	160.2	141.7			667.7	301.9
Cooper Industries plc [Member]
Consolidated Income Statements
Selling and administrative expenses	0.2	0.5			0	2.6
Equity in earnings of consolidated subsidiaries, net of tax	156.4	73.1			623.3	143.9
Intercompany income (expense)	(0.3)	(0.3)			(1.0)	0.1
Income (loss) before income taxes	155.9	72.3			622.3	141.4
Income from continuing operations					622.3
Net income	155.9	72.3			622.3	141.4
Cooper US, Inc. [Member]
Consolidated Income Statements
Cost of sales	(0.9)	(0.9)			(2.7)	(0.7)
Selling and administrative expenses	18.5	17.7			92.4	80.1
Loss related to contribution of net assets to Apex Tool Group, LLC						2.4
Interest expense, net	16.3	12.3			50.0	36.7
Equity in earnings of consolidated subsidiaries, net of tax	88.7	74.5			457.2	133.8
Intercompany income (expense)	(13.8)	(19.2)			(54.6)	(60.2)
Income (loss) before income taxes	41.0	26.2			262.9	(44.9)
Income tax expense (benefit)	(20.6)	(16.1)			(72.1)	(53.7)
Income from continuing operations					335.0
Net income	61.6	42.3			335.0	8.8
Guarantors [Member]
Consolidated Income Statements
Revenues	886.5	820.1			2,600.4	2,292.6
Cost of sales	621.9	579.4			1,822.5	1,626.2
Selling and administrative expenses	134.1	124.5			389.7	352.8
Restructuring charges		2.0				3.8
Equity in earnings of consolidated subsidiaries, net of tax	139.3	139.6			602.5	301.4
Intercompany income (expense)	(37.2)	(44.7)			(121.5)	(120.5)
Income (loss) before income taxes	232.6	209.1			869.2	490.7
Income tax expense (benefit)	33.7	33.4			105.5	84.5
Income from continuing operations					763.7
Net income	198.9	175.7			763.7	406.2
Other Subsidiaries [Member]
Consolidated Income Statements
Revenues	688.3	596.5			1,987.5	2,007.3
Cost of sales	495.3	419.0			1,413.8	1,406.1
Selling and administrative expenses	120.7	96.3			342.8	334.8
Equity in (income) of Apex Tool Group, LLC	(16.0)	(10.5)			(44.9)	(10.5)
Loss related to contribution of net assets to Apex Tool Group, LLC		(0.5)				131.6
Restructuring charges		(0.5)				4.2
Interest expense, net	0.1				(0.2)	(0.5)
Equity in earnings of consolidated subsidiaries, net of tax	207.2	42.2			480.6	8.7
Intercompany income (expense)	51.3	60.4			176.8	176.8
Income (loss) before income taxes	346.7	195.3			933.4	327.1
Income tax expense (benefit)	15.6	20.1			58.8	30.3
Income from continuing operations					874.6
Income related to discontinued operations, net of income taxes					190.3
Net income	331.1	175.2			1,064.9	296.8
Consolidating Adjustments [Member]
Consolidated Income Statements
Revenues	(185.1)	(175.9)			(551.6)	(493.9)
Cost of sales	(185.1)	(175.9)			(551.6)	(493.9)
Selling and administrative expenses	(4.3)	(2.3)			(45.1)	(33.2)
Loss related to contribution of net assets to Apex Tool Group, LLC		0.5				0.5
Equity in earnings of consolidated subsidiaries, net of tax	(591.6)	(329.4)			(2,163.6)	(587.8)
Intercompany income (expense)		3.8			0.3	3.8
Income (loss) before income taxes	587.3	(323.8)			(2,118.2)	(551.3)
Income from continuing operations					(2,118.2)
Net income	$ 587.3	$ (323.8)			$ (2,118.2)	$ (551.3)