Consolidating Financial Information - Consolidating Income Statements (Details) (USD $) In Millions	3 Months Ended			6 Months Ended		12 Months Ended
	Jun. 30, 2011	Jun. 30, 2010	Sep. 30, 2008	Jun. 30, 2011	Jun. 30, 2010	Dec. 31, 2009
Consolidated Income Statements [Abstract]
Revenues	$ 1,368.9	$ 1,336.7		$ 2,646.6	$ 2,565.3
Cost of sales	907.1	895.0		1,750.8	1,716.1
Selling and administrative expenses	259.7	255.6		510.6	500.4
Loss related to contribution of net assets to Apex Tool Group, LLC		134.5			134.5
Equity in (income) of Apex Tool Group, LLC	(14.4)			(28.9)
Restructuring charges		3.0			6.5
Interest expense, net	17.1	11.5		33.4	23.9
Income (loss) before income taxes	199.4	37.1		380.7	183.9
Income tax expense (benefit)	38.0	(4.5)		63.5	23.7
Income from continuing operations	161.4	41.6		317.2	160.2
Income related to discontinued operations, net of income taxes			16.6	190.3		25.5
Net income	161.4	41.6		507.5	160.2
Cooper Industries plc [Member]
Consolidated Income Statements [Abstract]
Selling and administrative expenses	0.2	2.1		0.2	2.1
Equity in earnings of consolidated subsidiaries, net of tax	146.6	23.3		466.9	70.8
Intercompany income (expense)	0.3	0.5		(0.7)	0.4
Income (loss) before income taxes	146.5	21.7		466.4	69.1
Income from continuing operations				466.4
Net income	146.5	21.7		466.4	69.1
Cooper US, Inc. [Member]
Consolidated Income Statements [Abstract]
Cost of sales	(1.2)	0.7		(1.8)	0.2
Selling and administrative expenses	29.6	15.8		73.9	62.4
Loss related to contribution of net assets to Apex Tool Group, LLC		2.4			2.4
Interest expense, net	17.2	12.1		33.7	24.4
Equity in earnings of consolidated subsidiaries, net of tax	124.1	(10.9)		368.5	59.3
Intercompany income (expense)	(23.7)	(20.1)		(40.8)	(41.0)
Income (loss) before income taxes	54.8	(62.0)		221.9	(71.1)
Income tax expense (benefit)	(19.6)	(19.8)		(51.5)	(37.6)
Income from continuing operations				273.4
Net income	74.4	(42.2)		273.4	(33.5)
Guarantors [Member]
Consolidated Income Statements [Abstract]
Revenues	877.3	777.5		1,713.9	1,472.5
Cost of sales	614.3	550.6		1,200.6	1,046.8
Selling and administrative expenses	129.6	117.5		255.6	228.3
Restructuring charges		1.4			1.8
Equity in earnings of consolidated subsidiaries, net of tax	173.1	58.0		463.2	161.8
Intercompany income (expense)	(42.8)	(36.5)		(84.3)	(75.8)
Income (loss) before income taxes	263.7	129.5		636.6	281.6
Income tax expense (benefit)	35.6	30.4		71.8	51.1
Income from continuing operations				564.8
Net income	228.1	99.1		564.8	230.5
Other Subsidiaries [Member]
Consolidated Income Statements [Abstract]
Revenues	679.7	730.7		1,299.2	1,410.8
Cost of sales	482.1	515.2		918.5	987.1
Selling and administrative expenses	115.5	120.2		222.1	238.5
Loss related to contribution of net assets to Apex Tool Group, LLC		132.1			132.1
Equity in (income) of Apex Tool Group, LLC	(14.4)			(28.9)
Restructuring charges		1.6			4.7
Interest expense, net	(0.1)	(0.6)		(0.3)	(0.5)
Equity in earnings of consolidated subsidiaries, net of tax	74.4	(42.2)		273.4	(33.5)
Intercompany income (expense)	66.7	56.1		125.5	116.4
Income (loss) before income taxes	237.7	(23.9)		586.7	131.8
Income tax expense (benefit)	22.0	(15.1)		43.2	10.2
Income from continuing operations				543.5
Income related to discontinued operations, net of income taxes				190.3
Net income	215.7	(8.8)		733.8	121.6
Consolidating Adjustments [Member]
Consolidated Income Statements [Abstract]
Revenues	(188.1)	(171.5)		(366.5)	(318.0)
Cost of sales	(188.1)	(171.5)		(366.5)	(318.0)
Selling and administrative expenses	(14.8)			(40.8)	(30.9)
Equity in earnings of consolidated subsidiaries, net of tax	(518.2)	(28.2)		(1,572.0)	(258.4)
Intercompany income (expense)	0.1			0.3
Income (loss) before income taxes	(503.3)	(28.2)		(1,530.9)	(227.5)
Income from continuing operations				(1,530.9)
Net income	$ (503.3)	$ (28.2)		$ (1,530.9)	$ (227.5)