Annual report pursuant to Section 13 and 15(d)

Marketable Securities Available-for-sale Securities (Details)

v3.8.0.1
Marketable Securities Available-for-sale Securities (Details) - USD ($)
$ in Millions
 12 Months Ended
Sep. 24, 2017
Sep. 25, 2016
Sep. 27, 2015
Contractual maturities of available-for-sale debt securities [Abstract]      
Years to Maturity - Less Than One Year $ 2,189    
Years to Maturity - One to Five Years 1,079    
Years to Maturity - Five to Ten Years 0    
Years to Maturity - Greater Than Ten Years 0    
Years to Maturity - No Single Maturity Date 241    
Realized Gains and Losses on Sales of Available-for-sale Securities [Abstract]      
Gross Realized Gains 553 $ 277 $ 540
Gross Realized Losses (127) (37) (52)
Net Realized Gains 426 240 $ 488
Available-for-sale Securities [Abstract]      
Available-for-sale Equity Securities, Amortized Cost Basis 8 1,554  
Available-for-sale Equity Securities, Accumulated Gross Unrealized Gain, before Tax 28 204  
Available-for-sale Equity Securities, Accumulated Gross Unrealized Loss, before Tax 0 (12)  
Available-for-sale Securities Equity Securities, Fair Value 36 1,746  
Available-for-sale Debt Securities (including debt funds), Amortized Cost Basis 3,497 24,363  
Available-for-sale Debt Securities (including debt funds), Accumulated Gross Unrealized Gain, before Tax 13 388  
Available-for-sale Debt Securities (including debt funds), Accumulated Gross Unrealized Loss, before Tax (1) (93)  
Available-for-sale Debt Securities, Fair Value 3,509 24,658  
Cost 3,505 25,917  
Available-for-sale Securities, Accumulated Gross Unrealized Gain, before Tax 41 592  
Available-for-sale Securities, Accumulated Gross Unrealized Loss, before Tax (1) (105)  
Fair Value 3,545 26,404  
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value   3,868  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss   (24)  
More than 12 months - Fair Value   1,699  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss   (81)  
U.S. Treasury securities and government-related securities [Member]      
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value   444  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss   (5)  
More than 12 months - Fair Value   16  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss   0  
Corporate bonds and notes [Member]      
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value 330 2,775  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss (1) (12)  
More than 12 months - Fair Value 21 1,033  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss $ 0 (65)  
Mortgage- and asset-backed and auction rate securities [Member]      
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value   337  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss   (3)  
More than 12 months - Fair Value   211  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss   (2)  
Equity and preferred securities and equity funds [Member]      
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value   312  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss   (4)  
More than 12 months - Fair Value   130  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss   (8)  
Debt funds [Member]      
Investments Classified as Available-for-sale in a Continuous Unrealized Loss Position Deemed to be Temporary [Abstract]      
Less than 12 months - Fair Value   0  
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss   0  
More than 12 months - Fair Value   309  
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss   $ (6)