Income Taxes - Additional Information (Details) - USD ($)	2 Months Ended	10 Months Ended	12 Months Ended
	Dec. 31, 2017	Oct. 31, 2018	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Operating Loss Carryforwards [Line Items]
Income tax expense (benefit)			$ (3,015,000)	$ 44,000	$ 519,000
U.S. federal corporate tax rate	34.00%	21.00%	23.20%	34.00%	34.00%
Reduction of valuation allowance attributable to deferred tax assets			$ 2,000,000
Deferred federal income tax expense (benefit)				$ 0	$ 0
Franchise tax expense			500,000	500,000	$ 400,000
Federal Operating Loss Carryforwards		$ 799,900,000	799,900,000
State Operating Loss Carryforwards		410,200,000	410,200,000
Tax Credits, State		8,300,000	8,300,000
Unrecognized Tax Benefits		$ 15,700,000	15,700,000	15,700,000
Unrecognized tax benefits, provision for interest or penalties			$ 0	$ 0
Federal [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date			Jan. 01, 2019
Federal [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date			Jan. 01, 2037
State [Member] | Minimum [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date		Jan. 01, 2019	Jan. 01, 2019
State [Member] | Maximum [Member]
Operating Loss Carryforwards [Line Items]
Tax Credit Carryforward, Expiration Date		Jan. 01, 2037	Jan. 01, 2037
IPR&D
Operating Loss Carryforwards [Line Items]
Reduction in deferred tax liability			$ 1,000,000