FAIR VALUE MEASUREMENTS (Details 3) $ in Millions	Apr. 30, 2016 USD ($)
Contractual Maturities of Debt Securities, Amortized Cost
Amortized cost, due in one year or less	$ 61
Amortized cost, due after one through five years	107
Amortized cost, due after five through 10 years	90
Amortized cost, due after 10 years	43
Amortized cost, mortgage-backed securities	120
Amortized cost, debt securities	421
Contractual Maturities of Debt Securities, Fair Value
Fair value, due in one year or less	61
Fair value, due after one through five years	103
Fair value, due after five through 10 years	94
Fair value, due after 10 years	46
Fair value, mortgage-backed securities	124
Fair value, debt securities	$ 428