Computation of Basic and Diluted Earnings Per Common Share (Detail) (USD $) In Millions, except Share data in Thousands, unless otherwise specified	3 Months Ended
	Dec. 31, 2011	Dec. 25, 2010
Numerator:
Net income	$ 13,064	$ 6,004
Denominator:
Weighted-average shares outstanding	931,041	919,294
Effect of dilutive securities	10,531	13,860
Weighted-average diluted shares	941,572	933,154
Basic earnings per common share	$ 14.03	$ 6.53
Diluted earnings per common share	$ 13.87	$ 6.43