Eaton Shareholders' Equity Eaton Shareholders' Equity - Net Income per Common Share (Details 1) (USD $) In Millions, except Per Share data, unless otherwise specified	12 Months Ended
	Dec. 31, 2011	Dec. 31, 2010	Dec. 31, 2009
Earnings Per Share Reconciliation [Abstract]
Net income attributable to Eaton common shareholders	$ 1,350	$ 929	$ 383
Weighted-average number of shares outstanding-diluted	342.8	339.5	335.8
Less dilutive effect of stock options and restricted stock awards	4.5	4.0	3.1
Weighted-average number of shares outstanding-basic	338.3	335.5	332.7
Net income per common share, diluted	$ 3.93	$ 2.73	$ 1.14
Net income per common share, basic	$ 3.98	$ 2.76	$ 1.16