Segment Information (Detail 3) - USD ($) $ in Millions	3 Months Ended								12 Months Ended
	Oct. 31, 2018	Jul. 31, 2018	Apr. 30, 2018	Jan. 31, 2018	Oct. 31, 2017	Jul. 31, 2017	Apr. 30, 2017	Jan. 31, 2017	Oct. 31, 2018	Oct. 31, 2017	Oct. 31, 2016
Segment Reporting Information
Net revenue	$ 7,946	$ 7,764	$ 7,468	$ 7,674	$ 7,660	$ 7,501	$ 6,808	$ 6,902	$ 30,852	$ 28,871	$ 30,280
Net property, plant and equipment:
Property, plant and equipment	6,138				6,269				6,138	6,269
U.S.
Segment Reporting Information
Net revenue									10,192	10,022	10,333
Net property, plant and equipment:
Property, plant and equipment	2,813				2,673				2,813	2,673
Other countries
Segment Reporting Information
Net revenue									20,660	18,849	$ 19,947
Net property, plant and equipment:
Property, plant and equipment	$ 3,325				$ 3,596				$ 3,325	$ 3,596