Financial Assets and Liabilities - Short-term investments (Details) - USD ($) $ in Thousands		Jan. 31, 2016	Oct. 31, 2015
Cash equivalents
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		$ 207,497	$ 239,473
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	(1)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	207,497	239,472
Cash equivalents | Money market funds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		199,561	233,839
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	0
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	199,561	233,839
Cash equivalents | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		1,199	1,834
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	0
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	1,199	1,834
Cash equivalents | U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		4,337
Gross unrealized gains		0
Gross unrealized losses less than 12 months		0
Gross unrealized losses 12 months or longer		0
Estimated fair value	[1]	4,337
Cash equivalents | Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		2,400	3,500
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	0
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	2,400	3,500
Cash equivalents | Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost			300
Gross unrealized gains			0
Gross unrealized losses less than 12 months			(1)
Gross unrealized losses 12 months or longer			0
Estimated fair value	[1]		299
Short-term investments
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		123,022	128,774
Gross unrealized gains		20	33
Gross unrealized losses less than 12 months		(94)	(60)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	122,948	128,747
Short-term investments | Commercial paper
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		11,430	12,129
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	0
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	11,430	12,129
Short-term investments | U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		13,718	12,615
Gross unrealized gains		6	3
Gross unrealized losses less than 12 months		(6)	(4)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	13,718	12,614
Short-term investments | Municipal bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		1,402	1,403
Gross unrealized gains		1	1
Gross unrealized losses less than 12 months		0	(1)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	1,403	1,403
Short-term investments | Certificates of deposit
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		8,297	9,800
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		0	0
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	8,297	9,800
Short-term investments | Corporate debt securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		65,160	67,201
Gross unrealized gains		8	27
Gross unrealized losses less than 12 months		(61)	(40)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	65,107	67,188
Short-term investments | Asset-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		22,009	24,619
Gross unrealized gains		5	2
Gross unrealized losses less than 12 months		(25)	(13)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	21,989	24,608
Short-term investments | Non-U.S. government agency securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale securities, cost		1,006	1,007
Gross unrealized gains		0	0
Gross unrealized losses less than 12 months		(2)	(2)
Gross unrealized losses 12 months or longer		0	0
Estimated fair value	[1]	$ 1,004	$ 1,005

[1] See Note 5. Fair Value Measures for further discussion on fair values of cash equivalents and short-term investments.