FAIR VALUE MEASUREMENTS (Details) - USD ($) $ in Thousands	Apr. 30, 2016	Oct. 31, 2015
Assets:
U.S. government obligations	$ 320,412
Fair Value, Measurements, Recurring
Assets:
Money market funds	749,856	$ 642,073
U.S. government obligations	315,415	205,223
Commercial paper	69,969	74,983
Foreign currency forward contracts	1,173	89
Total assets measured at fair value	1,136,413	922,368
Liabilities:
Foreign currency forward contracts and forward starting interest rate swaps	548	512
Total liabilities measured at fair value	5,976	6,034
Fair Value, Measurements, Recurring | Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging
Liabilities:
Foreign currency forward contracts and forward starting interest rate swaps	5,428	5,522
Fair Value, Measurements, Recurring | Level 1
Assets:
Money market funds	749,856	642,073
Total assets measured at fair value	749,856	642,073
Liabilities:
Total liabilities measured at fair value	0	0
Fair Value, Measurements, Recurring | Level 2
Assets:
U.S. government obligations	315,415	205,223
Commercial paper	69,969	74,983
Foreign currency forward contracts	1,173	89
Total assets measured at fair value	386,557	280,295
Liabilities:
Foreign currency forward contracts and forward starting interest rate swaps	548	512
Total liabilities measured at fair value	5,976	6,034
Fair Value, Measurements, Recurring | Level 2 | Interest Rate Swap | Designated as Hedging Instrument | Cash Flow Hedging
Liabilities:
Foreign currency forward contracts and forward starting interest rate swaps	5,428	5,522
Fair Value, Measurements, Recurring | Level 3
Assets:
Total assets measured at fair value	0	0
Liabilities:
Total liabilities measured at fair value	$ 0	$ 0