Share Repurchases in the Open Market (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	3 Months Ended		9 Months Ended
	Jun. 30, 2014		Jun. 30, 2014
Stockholders' Equity Note [Abstract]
Shares repurchased in the open market	6	[1]	16	[1]
Weighted-average repurchase price per share	$ 207.13		$ 207.90
Total cost	$ 1,152		$ 3,362

[1] All shares repurchased in the open market have been retired and constitute authorized but unissued shares.