EARNINGS PER SHARE CALCULATION (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Apr. 30, 2017	Apr. 30, 2016	Apr. 30, 2017	Apr. 30, 2016
Numerator
Net income	$ 38,026	$ 13,997	$ 41,887	$ 2,451
Net income used to calculate Diluted EPS	$ 42,109	$ 13,997	$ 42,984	$ 2,451
Denominator
Basic weighted average shares outstanding (in shares)	141,743	137,950	141,223	137,313
Add: Shares underlying outstanding stock options and restricted stock units and issuable under employee stock purchase plan (in shares)	1,317	939	1,409	1,380
Dilutive weighted average shares outstanding (in shares)	165,273	138,889	147,842	138,693
EPS
Basic EPS (in dollars per share)	$ 0.27	$ 0.10	$ 0.30	$ 0.02
Diluted EPS (in dollars per share)	$ 0.25	$ 0.10	$ 0.29	$ 0.02
0.875% Convertible Senior Notes due June 15, 2017
Numerator
Interest expense associated with Convertible Senior Notes	$ 495	$ 0	$ 1,097	$ 0
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	4,857	0	5,210	0
3.75% Convertible Senior Notes due October 15, 2018
Numerator
Interest expense associated with Convertible Senior Notes	$ 3,588	$ 0	$ 0	$ 0
Denominator
Add: Shares underlying Convertible Senior Notes (in shares)	17,356	0	0	0