Consolidating Financial Information - Consolidating Balance Sheets (Details 1) (USD $) In Millions	Sep. 30, 2011	Dec. 31, 2010	Sep. 30, 2010	Dec. 31, 2009
Consolidated Balance Sheets
Cash and cash equivalents	$ 430.6	$ 1,035.3	$ 296.0	$ 381.6
Receivables, less allowances	942.3	795.9
Inventories	506.3	438.9
Current discontinued operations receivable	3.8	13.0
Other current assets	225.8	207.5
Total current assets	2,108.8	2,490.6
Property, plant and equipment, less accumulated depreciation	615.7	608.3
Investment in Apex Tool Group, LLC	531.2	511.3
Investment in subsidiaries	0	0
Investment in parent	0	0
Intercompany accounts receivable	0	0
Intercompany notes receivable	0	0
Goodwill	2,513.6	2,356.5
Other intangible assets, less accumulated amortization	372.6	333.6
Long-term discontinued operations receivable	5.1	150.6
Other noncurrent assets	175.0	217.7
Total assets	6,322.0	6,668.6
Short-term debt	6.2	7.7
Accounts payable	465.4	462.6
Accrued liabilities	527.7	510.1
Current discontinued operations liability	9.4	45.4
Current maturities of long-term debt	0.7	0.6
Total current liabilities	1,009.4	1,026.4
Long-term debt	1,420.9	1,420.4
Intercompany accounts payable	0	0
Intercompany notes payable	0	0
Long-term discontinued operations liability	40.5	701.7
Other long-term liabilities	398.2	314.0
Total liabilities	2,869.0	3,462.5
Common stock	1.7	1.7
Subsidiary preferred stock	0	0
Subsidiary common stock	0	0
Capital in excess of par value	0	0
Retained earnings	4,288.9	3,658.7
Treasury stock	(671.6)	(288.6)
Accumulated other nonowner changes in equity	(166.0)	(165.7)
Total shareholders' equity	3,453.0	3,206.1
Total liabilities and shareholders' equity	6,322.0	6,668.6
Cooper Industries plc [Member]
Consolidated Balance Sheets
Cash and cash equivalents	78.0	63.2	58.8	146.0
Receivables, less allowances	0.2	0
Inventories	0	0
Current discontinued operations receivable	0	0
Other current assets	0.9	0.6
Total current assets	79.1	63.8
Property, plant and equipment, less accumulated depreciation	0	0
Investment in Apex Tool Group, LLC	0	0
Investment in subsidiaries	990.3	3,035.5
Investment in parent	0	0
Intercompany accounts receivable	81.4	71.9
Intercompany notes receivable	9,564.5	40.0
Goodwill	0	0
Other intangible assets, less accumulated amortization	0	0
Long-term discontinued operations receivable	0	0
Other noncurrent assets	0.5	0
Total assets	10,715.8	3,211.2
Short-term debt	0	0
Accounts payable	46.6	44.7
Accrued liabilities	1.3	1.2
Current discontinued operations liability	0	0
Current maturities of long-term debt	0	0
Total current liabilities	47.9	45.9
Long-term debt	0	0
Intercompany accounts payable	0	0
Intercompany notes payable	419.1	419.7
Long-term discontinued operations liability	0	0
Other long-term liabilities	0	0
Total liabilities	467.0	465.6
Common stock	1.7	1.7
Subsidiary preferred stock	0	0
Subsidiary common stock	0	0
Capital in excess of par value	10,251.5	2,811.0
Retained earnings	624.2	145.0
Treasury stock	(671.6)	(288.6)
Accumulated other nonowner changes in equity	43.0	76.5
Total shareholders' equity	10,248.8	2,745.6
Total liabilities and shareholders' equity	10,715.8	3,211.2
Cooper US, Inc. [Member]
Consolidated Balance Sheets
Cash and cash equivalents	118.6	36.8	59.3	27.9
Receivables, less allowances	0.5	2.5
Inventories	0	0
Current discontinued operations receivable	0	0
Other current assets	73.6	72.4
Total current assets	192.7	111.7
Property, plant and equipment, less accumulated depreciation	38.8	42.1
Investment in Apex Tool Group, LLC	0	0
Investment in subsidiaries	3,371.5	2,923.6
Investment in parent	3,428.0	3,428.1
Intercompany accounts receivable	0	0
Intercompany notes receivable	564.9	1,674.8
Goodwill	0	0
Other intangible assets, less accumulated amortization	0	0
Long-term discontinued operations receivable	0	0
Other noncurrent assets	(3.9)	13.1
Total assets	7,592.0	8,193.4
Short-term debt	0	0
Accounts payable	23.9	20.3
Accrued liabilities	59.8	66.3
Current discontinued operations liability	0	0
Current maturities of long-term debt	0	0
Total current liabilities	83.7	86.6
Long-term debt	1,419.4	1,418.5
Intercompany accounts payable	2,167.1	3,290.2
Intercompany notes payable	1,815.1	1,587.2
Long-term discontinued operations liability	0	0
Other long-term liabilities	34.8	103.6
Total liabilities	5,520.1	6,486.1
Common stock	0	0
Subsidiary preferred stock	0	0
Subsidiary common stock	0	0
Capital in excess of par value	820.9	770.4
Retained earnings	1,377.9	1,049.4
Treasury stock	0	0
Accumulated other nonowner changes in equity	(126.9)	(112.5)
Total shareholders' equity	2,071.9	1,707.3
Total liabilities and shareholders' equity	7,592.0	8,193.4
Guarantors [Member]
Consolidated Balance Sheets
Cash and cash equivalents	8.1	2.6	1.4	0.3
Receivables, less allowances	266.8	218.7
Inventories	257.9	234.7
Current discontinued operations receivable	0	0
Other current assets	38.0	30.7
Total current assets	570.8	486.7
Property, plant and equipment, less accumulated depreciation	320.8	316.8
Investment in Apex Tool Group, LLC	0	0
Investment in subsidiaries	5,244.8	4,608.9
Investment in parent	0	0
Intercompany accounts receivable	1,102.3	1,974.1
Intercompany notes receivable	6,956.3	3,348.3
Goodwill	1,288.3	1,288.3
Other intangible assets, less accumulated amortization	85.3	85.7
Long-term discontinued operations receivable	0	0
Other noncurrent assets	1.5	(178.2)
Total assets	15,570.1	11,930.6
Short-term debt	0	0
Accounts payable	173.1	201.8
Accrued liabilities	212.6	210.4
Current discontinued operations liability	0	0
Current maturities of long-term debt	0	0
Total current liabilities	385.7	412.2
Long-term debt	0	0
Intercompany accounts payable	0	0
Intercompany notes payable	1,849.0	4,436.2
Long-term discontinued operations liability	0	0
Other long-term liabilities	203.2	54.5
Total liabilities	2,437.9	4,902.9
Common stock	0	0
Subsidiary preferred stock	2,872.0	2,872.1
Subsidiary common stock	9.2	9.2
Capital in excess of par value	6,300.5	1,936.7
Retained earnings	4,089.5	2,288.5
Treasury stock	0	0
Accumulated other nonowner changes in equity	(139.0)	(78.8)
Total shareholders' equity	13,132.2	7,027.7
Total liabilities and shareholders' equity	15,570.1	11,930.6
Other Subsidiaries [Member]
Consolidated Balance Sheets
Cash and cash equivalents	225.9	932.7	176.5	207.4
Receivables, less allowances	674.8	574.7
Inventories	248.4	204.2
Current discontinued operations receivable	3.8	13.0
Other current assets	113.3	103.8
Total current assets	1,266.2	1,828.4
Property, plant and equipment, less accumulated depreciation	256.1	249.4
Investment in Apex Tool Group, LLC	531.2	511.3
Investment in subsidiaries	4,865.0	741.6
Investment in parent	312.7	312.7
Intercompany accounts receivable	983.4	1,244.2
Intercompany notes receivable	4,003.6	5,394.7
Goodwill	1,225.3	1,068.2
Other intangible assets, less accumulated amortization	287.3	247.9
Long-term discontinued operations receivable	5.1	150.6
Other noncurrent assets	176.9	382.8
Total assets	13,912.8	12,131.8
Short-term debt	6.2	7.7
Accounts payable	221.8	195.8
Accrued liabilities	255.6	233.6
Current discontinued operations liability	9.4	45.4
Current maturities of long-term debt	0.7	0.6
Total current liabilities	493.7	483.1
Long-term debt	1.5	1.9
Intercompany accounts payable	0	0
Intercompany notes payable	17,006.1	4,014.7
Long-term discontinued operations liability	40.5	701.7
Other long-term liabilities	160.2	155.9
Total liabilities	17,702.0	5,357.3
Common stock	0	0
Subsidiary preferred stock	335.1	335.1
Subsidiary common stock	257.8	257.8
Capital in excess of par value	(8,320.4)	2,106.3
Retained earnings	4,106.6	4,133.5
Treasury stock	0	0
Accumulated other nonowner changes in equity	(168.3)	(58.2)
Total shareholders' equity	(3,789.2)	6,774.5
Total liabilities and shareholders' equity	13,912.8	12,131.8
Consolidating Adjustments [Member]
Consolidated Balance Sheets
Cash and cash equivalents	0	0	0	0
Receivables, less allowances	0	0
Inventories	0	0
Current discontinued operations receivable	0	0
Other current assets	0	0
Total current assets	0	0
Property, plant and equipment, less accumulated depreciation	0	0
Investment in Apex Tool Group, LLC	0	0
Investment in subsidiaries	(14,471.6)	(11,309.6)
Investment in parent	(3,740.7)	(3,740.8)
Intercompany accounts receivable	(2,167.1)	(3,290.2)
Intercompany notes receivable	(21,089.3)	(10,457.8)
Goodwill	0	0
Other intangible assets, less accumulated amortization	0	0
Long-term discontinued operations receivable	0	0
Other noncurrent assets	0	0
Total assets	(41,468.7)	(28,798.4)
Short-term debt	0	0
Accounts payable	0	0
Accrued liabilities	(1.6)	(1.4)
Current discontinued operations liability	0	0
Current maturities of long-term debt	0	0
Total current liabilities	(1.6)	(1.4)
Long-term debt	0	0
Intercompany accounts payable	(2,167.1)	(3,290.2)
Intercompany notes payable	(21,089.3)	(10,457.8)
Long-term discontinued operations liability	0	0
Other long-term liabilities	0	0
Total liabilities	(23,258.0)	(13,749.4)
Common stock	0	0
Subsidiary preferred stock	(3,207.1)	(3,207.2)
Subsidiary common stock	(267.0)	(267.0)
Capital in excess of par value	(9,052.5)	(7,624.4)
Retained earnings	(5,909.3)	(3,957.7)
Treasury stock	0	0
Accumulated other nonowner changes in equity	225.2	7.3
Total shareholders' equity	(18,210.7)	(15,049.0)
Total liabilities and shareholders' equity	$ (41,468.7)	$ (28,798.4)