SHORT-TERM AND LONG-TERM INVESTMENTS (Details) - USD ($) $ in Thousands	Jan. 31, 2017	Oct. 31, 2016
Long Term Investments
Amortized Cost		$ 360,077
Estimated Fair Value	$ 359,990
U.S. government obligations
Long Term Investments
Amortized Cost	340,125	350,270
Gross Unrealized Gains	65	197
Gross Unrealized Losses	(152)	(36)
Estimated Fair Value	340,038	350,431
U.S. government obligations \| Included in short-term investments
Long Term Investments
Amortized Cost	230,090	260,125
Gross Unrealized Gains	60	140
Gross Unrealized Losses	(46)	(6)
Estimated Fair Value	230,104	260,259
U.S. government obligations \| Included in long-term investments
Long Term Investments
Amortized Cost	110,035	90,145
Gross Unrealized Gains	5	57
Gross Unrealized Losses	(106)	(30)
Estimated Fair Value	109,934	90,172
Commercial paper
Long Term Investments
Amortized Cost	19,952	14,989
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	19,952	14,989
Commercial paper \| Included in short-term investments
Long Term Investments
Amortized Cost	19,952	14,989
Gross Unrealized Gains	0	0
Gross Unrealized Losses	0	0
Estimated Fair Value	$ 19,952	$ 14,989

This item represents the cost of debt securities, which are categorized neither as held-to-maturity nor trading, net of adjustments including accretion, amortization, collection of cash, previous other-than-temporary impairments recognized in earnings (less any cumulative-effect adjustments recognized, as defined), and fair value hedge accounting adjustments, if any.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 320
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (aa)
-URI http://asc.fasb.org/extlink&oid=73527792&loc=d3e27161-111563

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.2)
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Amount of investment in debt and equity securities categorized neither as held-to-maturity nor trading.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
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Reference 2: http://www.xbrl.org/2003/role/presentationRef
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