Annual report pursuant to Section 13 and 15(d)

Marketable Securities (Details)

v2.4.0.8
Marketable Securities (Details) (USD $)
In Millions, unless otherwise specified
 12 Months Ended
Sep. 28, 2014
Sep. 29, 2013
Sep. 30, 2012
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value $ 5,906 $ 5,642  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (38) (204)  
Marketable Securities [Abstract]      
Effective ownership interest in debt fund (fair value option) 26.00%    
Net losses recognized on debt securities classified as trading that are still held at the end of the period (5) (20)  
More than 12 months - Fair value 675 135  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (28) (2)  
U.S. Treasury securities and government-related securities [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 279 42  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (2) (1)  
Marketable Securities [Abstract]      
More than 12 months - Fair value 0 0  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss 0 0  
Corporate bonds and notes [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 4,924 2,084  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (31) (31)  
Marketable Securities [Abstract]      
More than 12 months - Fair value 104 24  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (4) (1)  
Mortgage- and asset-backed securities [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 484 367  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (1) (5)  
Marketable Securities [Abstract]      
More than 12 months - Fair value 52 24  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (1) 0  
Auction rate securities [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 0 0  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss 0 0  
Marketable Securities [Abstract]      
More than 12 months - Fair value 83 83  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (1) (1)  
Common and preferred stock [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 86 291  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (3) (41)  
Marketable Securities [Abstract]      
More than 12 months - Fair value 52 0  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (3) 0  
Other Debt Obligations [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value 133 2,776  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss (1) (123)  
Marketable Securities [Abstract]      
Net increases in fair value of the debt fund 33 17 45
More than 12 months - Fair value 384 4  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss (19) 0  
Equity funds [Member]
      
Schedule of Marketable Securities [Line Items]      
Less than 12 months - Fair value   82  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Loss   (3)  
Marketable Securities [Abstract]      
More than 12 months - Fair value   0  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Loss   $ 0