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NORTHERN CALIFORNIA WILDFIRES IMPACT Charges in consolidated statement of operations (Details) - USD ($)
$ in Millions
3 Months Ended 6 Months Ended
Apr. 30, 2019
Apr. 30, 2018
Apr. 30, 2019
Apr. 30, 2018
Unusual or Infrequent Item, or Both [Line Items]        
Loss from Catastrophes $ 0 $ 0 $ 0 $ 7