Earnings Per Share Calculation - Earnings Per Share Calculation (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended
	Jan. 31, 2019	Jan. 31, 2018
Numerator
Net income (loss)	$ 33,616	$ (473,363)
Denominator
Basic weighted average shares outstanding (in shares)	156,314	143,922
Add: Shares underlying outstanding stock options and restricted stock units and issuable under employee stock purchase plan (in shares)	1,860	0
Dilutive weighted average shares outstanding (in shares)	158,174	143,922
EPS
Basic EPS (in dollars per share)	$ 0.22	$ (3.29)
Diluted EPS (in dollars per share)	$ 0.21	$ (3.29)