Equity-Based Compensation - Additional Information (Detail) (USD $) In Millions, except Per Share data, unless otherwise specified	1 Months Ended	6 Months Ended
	Mar. 31, 2012	Mar. 31, 2012	Apr. 02, 2011
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Weighted average grant date fair values of options issued		$ 10.58	$ 10.96
Stock compensation granted, number of shares		18.8
Increase in number of shares authorized to be awarded as grants	15
Stock Options
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	217	$ 217
Stock compensation granted, number of shares		9.8
Number of shares authorized to be awarded as grants	131	131
Restricted Stock Units
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost	734	$ 734
Stock compensation granted, number of shares		8.6
Number of shares authorized to be awarded as grants	66	66
Restrict Stock With Market and Performance Conditions
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Stock compensation granted, number of shares		0.5