Equity - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended			6 Months Ended
	Mar. 31, 2012	Dec. 31, 2011	Apr. 02, 2011	Mar. 31, 2012	Apr. 02, 2011
Stockholders Equity Note [Line Items]
Dividend declared, amount		$ 1,100
Dividend declared, per share		$ 0.60
Dividend, declared date		Nov. 30, 2011
Dividend, record date		Dec. 16, 2011
Dividend, payment date		Jan. 18, 2012
Dividend paid			756	1,076	756
Dividend paid, per share			$ 0.40
Common stock repurchases (in shares)				45
Common stock repurchases	869		805	1,669	1,602
Remaining additional shares authorized to repurchase	260			260
Total par value of outstanding common stock	$ 28			$ 28