Restructuring and Impairments - Restructuring Reserve by Type (Details) - USD ($) $ in Millions	3 Months Ended		6 Months Ended
	Apr. 30, 2016	Apr. 30, 2015	Apr. 30, 2016	Apr. 30, 2015	Oct. 31, 2015	Oct. 31, 2014
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 3	$ 6	$ 6	$ 9
Restructuring Reserve	22	18	22	18	$ 68	$ 20
Restructuring and Related Cost, Incurred Cost			6	7
Payments for Restructuring			52	8
Restructuring Reserve, Accrual Adjustment			0	(1)
Employee Severance [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	19	10	19	10	62	8
Restructuring and Related Cost, Incurred Cost			6	7
Payments for Restructuring			49	4
Restructuring Reserve, Accrual Adjustment			0	(1)
Lease Vacancy [Member] [Domain]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	2	7	2	7	5	11
Restructuring and Related Cost, Incurred Cost			0	0
Payments for Restructuring			3	4
Restructuring Reserve, Accrual Adjustment			0	0
Other Restructuring [Member]
Restructuring Cost and Reserve [Line Items]
Restructuring Reserve	$ 1	$ 1	1	1	$ 1	$ 1
Restructuring and Related Cost, Incurred Cost			0	0
Payments for Restructuring			0	0
Restructuring Reserve, Accrual Adjustment			$ 0	$ 0