Income Taxes - Narrative (Details) - USD ($) $ in Millions	1 Months Ended	3 Months Ended
	Jan. 31, 2019	Jan. 31, 2020	Jan. 31, 2019
Operating Loss Carryforwards [Line Items]
Unusual or Infrequent Item, or Both, Tax Effect	$ 19	$ 5	$ 38
Income Tax Expense (Benefit)		$ (5)	$ (19)