Benefit Plans - Fair Value of Shares Issued under Previous Employee Stock Purchase Plan Determined at Grant Date (Details)	12 Months Ended
	Oct. 31, 2017	Oct. 31, 2016
Disclosure Of Compensation Related Costs Sharebased Payments [Abstract]
Expected life (in years)	6 months	6 months
Risk free interest rate	0.46%	0.30%
Volatility	75.00%	37.00%
Dividends yield	0.00%	0.00%