Income Taxes Cash paid for taxes (Details) - USD ($) $ in Thousands	3 Months Ended		12 Months Ended
	Jan. 31, 2018	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Tax Credit Carryforward [Line Items]
Cash paid for (refund of) income taxes	$ 3,423	$ 1,780	$ 3,423	$ 1,780	$ (5,855)
Effective income tax rate change in enacted tax rate, amount			(3,966)	$ 0	$ 0
Research Tax Credit Carryforward [Member]
Tax Credit Carryforward [Line Items]
Deferred Tax Assets, Tax Credit Carryforwards, Research			$ 4,873