v2.4.0.8
Collateral (Detail) (USD $)
In Millions, unless otherwise specified
Jun. 30, 2013
Sep. 30, 2012
Settlement Guarantee Management [Abstract]    
Cash equivalents $ 817 $ 823
Pledged securities at market value 264 307
Letters of credit 1,157 1,084
Guarantees 2,088 2,022
Total $ 4,326 $ 4,236