Earnings Per Share, Share Repurchases and Dividends on Common Stock (Unaudited) (Details) (USD $) Share data in Millions, except Per Share data, unless otherwise specified	3 Months Ended							6 Months Ended
	Mar. 31, 2012	Jun. 30, 2011	Mar. 31, 2011	Mar. 31, 2012 June 2010 Share Repurchase Program Original Authorization		Mar. 31, 2011 June 2010 Share Repurchase Program Original Authorization		Jun. 30, 2010 June 2010 Share Repurchase Program Original Authorization	Apr. 25, 2011 June 2010 Share Repurchase Program Original Authorization
Share Repurchase [Line Items]
Dilutive effect of of stock awards granted to employees under stock-based compensation plans	4.9		5.1
Anti-dilutive shares excluded from computation of earnings per share	2.8		2.8
Share Repurchases (Table Amounts)
Amount Authorized				$ 4,245,000,000	[1]			$ 2,000,000,000
Total Shares Retired				48.5	[1]
Average Price Per Share				$ 57.63	[1],[2]
Shares Repurchased				4.4	[1]	0.1	[1]
Share Repurchased Amount									245,000,000
Share Repurchases (Amounts in Paragraphs)
Increase authorized				4,000,000,000
Amount remaining under authorization for share repurchases				$ 1,400,000,000
Share Repurchase Limit Due to IRS Action	43		88
Period Of Share Repurchase Limit			2 years
Common stock dividends per share, declared		$ 0.50	$ 0.47

[1] On June 16, 2010, the company’s board of directors authorized a share repurchase program of up to $2.0 billion of the company’s common stock. On April 25, 2011, after the company had repurchased shares totaling $245 million, the company’s board of directors authorized an increase to the remaining share repurchase authorization to $4.0 billion. As of March 31, 2012, the company had $1.4 billion remaining under this authorization for share repurchases.

[2] Calculated as the average price paid per share under the respective repurchase program, including commissions paid.