FAIR VALUE MEASUREMENTS (Details 3) $ in Millions	Jan. 31, 2016 USD ($)
Contractual Maturities of Debt Securities, Amortized Cost
Amortized cost, due in one year or less	$ 50
Amortized cost, due after one through five years	127
Amortized cost, due after five through 10 years	100
Amortized cost, due after 10 years	40
Amortized cost, mortgage-backed securities	114
Amortized cost, debt securities	431
Contractual Maturities of Debt Securities, Fair Value
Fair value, due in one year or less	48
Fair value, due after one through five years	121
Fair value, due after five through 10 years	103
Fair value, due after 10 years	43
Fair value, mortgage-backed securities	117
Fair value, debt securities	$ 432