Annual report pursuant to Section 13 and 15(d)

Marketable Securities (Details)

Marketable Securities (Details) (USD $)
In Millions, unless otherwise specified
12 Months Ended
Sep. 30, 2012
Sep. 25, 2011
Marketable Securities [Abstract]    
Effective ownership interest in debt fund (fair value option) 22.00%  
Increases in fair value of debt fund (fair value option) recognized in investment income $ 45 $ 9
Net gains recognized on debt securities classified as trading that are still held at the end of the period $ 22 $ 0