CONSOLIDATED BALANCE SHEETS (Parenthetical) (USD $)
In Millions, except Per Share data, unless otherwise specified
Mar. 31, 2015
Sep. 30, 2014
Preferred Stock    
Preferred stock, par value $ 0.0001 $ 0.0001
Preferred stock, shares authorized 25 25
Preferred stock, shares issued 0 0
Class A common stock    
Common stock, par value $ 0.0001 $ 0.0001
Common stock, shares authorized 2,001,622 2,001,622
Common stock, shares issued 1,964 1,978
Common stock, shares outstanding 1,964 1,978
Class B common stock    
Common stock, par value $ 0.0001 $ 0.0001
Common stock, shares authorized 622 622
Common stock, shares issued 245 245
Common stock, shares outstanding 245 245
Class C common stock    
Common stock, par value $ 0.0001 $ 0.0001
Common stock, shares authorized 1,097 1,097
Common stock, shares issued 20 22
Common stock, shares outstanding 20 22