Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	2 Months Ended	12 Months Ended
	Dec. 31, 2018	Oct. 31, 2018	Oct. 31, 2017
Statement of Comprehensive Income [Abstract]
Net loss after income taxes	$ (18,418)	$ (65,441)	$ (130,829)
Other comprehensive income:
Unrealized gain on available-for-sale securities	36
Comprehensive loss	$ (18,382)	$ (65,441)	$ (130,829)