v2.4.0.8
Fair Value Measurements and Investments Assets and Liabilities Measured at Fair Value on a Recurring Basis (Details) (Fair Value, Measurements, Recurring, USD $)
In Millions, unless otherwise specified
Jun. 30, 2013
Sep. 30, 2012
Accrued liabilities    
Visa Europe put option $ 145 $ 145
Level 1
   
Prepaid and other current assets:    
Fair value, total assets 2,327 6,810
Accrued liabilities    
Fair value, total liabilities 0 0
Level 2
   
Prepaid and other current assets:    
Fair value, total assets 3,467 2,990
Accrued liabilities    
Fair value, total liabilities 6 11
Level 3
   
Prepaid and other current assets:    
Fair value, total assets 7 7
Accrued liabilities    
Fair value, total liabilities 145 157
Visa Europe put option | Level 3
   
Accrued liabilities    
Visa Europe put option 145 145
Earn-out related to PlaySpan acquisition | Level 3
   
Accrued liabilities    
Earn-out related to PlaySpan acquisition 0 12
Foreign exchange derivative instruments | Level 2
   
Accrued liabilities    
Foreign exchange derivative instruments 6 11
Money market funds | Level 1
   
Cash equivalents and restricted cash:    
Cash equivalents and restricted cash: 620 5,676
Commercial paper | Level 2
   
Cash equivalents and restricted cash:    
Cash equivalents and restricted cash: 52 93
Equity securities | Level 1
   
Investment securities:    
Trading securities 73 66
Available-for-sale securities 60 2
U.S. government-sponsored debt securities | Level 2
   
Investment securities:    
Available-for-sale securities 2,880 2,821
U.S. Treasury securities | Level 1
   
Investment securities:    
Available-for-sale securities 1,574 1,066
Corporate Debt Securities [Member] | Level 2
   
Investment securities:    
Available-for-sale securities 491 63
Auction rate securities | Level 3
   
Investment securities:    
Available-for-sale securities 7 7
Foreign exchange derivative instruments | Level 2
   
Prepaid and other current assets:    
Prepaid and other current assets: $ 44 $ 13