Fair Value (Details) - USD ($) $ in Millions	Jul. 31, 2016	Oct. 31, 2015	Jul. 31, 2015
Financial assets and liabilities measured at fair value on a recurring basis
Transfer of marketable equity securities from Level 2 to Level 1			$ 41
Fair Value and Carrying Value of Debt
Fair value, short-term and long-term debt	$ 16,400
Carrying value, short-term and long-term debt	16,300	$ 15,800
Fair Value, Measurements, Recurring
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	9,825	8,536
Total liabilities	303	192
Fair Value, Measurements, Recurring | Time deposits
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	3,653	2,473
Fair Value, Measurements, Recurring | Time deposits | MphasiS
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	73
Fair Value, Measurements, Recurring | Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	4,983	4,592
Fair Value, Measurements, Recurring | Mutual funds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	0	246
Fair Value, Measurements, Recurring | Mutual funds | MphasiS
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	314
Fair Value, Measurements, Recurring | Equity securities in public companies
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	25	53
Fair Value, Measurements, Recurring | Foreign bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	297	313
Fair Value, Measurements, Recurring | Foreign bonds | MphasiS
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	38
Fair Value, Measurements, Recurring | Other debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	36	40
Fair Value, Measurements, Recurring | Interest rate contracts
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	239
Total liabilities		55
Fair Value, Measurements, Recurring | Foreign currency contracts
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	587	816
Total liabilities	303	137
Fair Value, Measurements, Recurring | Foreign currency contracts | MphasiS
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	9
Total liabilities	2
Fair Value, Measurements, Recurring | Other derivatives
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	5	3
Fair Value, Measurements, Recurring | Level 1
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	5,016	4,646
Fair Value, Measurements, Recurring | Level 1 | Money market funds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	4,983	4,592
Fair Value, Measurements, Recurring | Level 1 | Equity securities in public companies
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	25	46
Fair Value, Measurements, Recurring | Level 1 | Foreign bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	8	8
Fair Value, Measurements, Recurring | Level 2
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	4,773	3,850
Total liabilities	303	192
Fair Value, Measurements, Recurring | Level 2 | Time deposits
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	3,653	2,473
Fair Value, Measurements, Recurring | Level 2 | Mutual funds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	0	246
Fair Value, Measurements, Recurring | Level 2 | Equity securities in public companies
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	0	7
Fair Value, Measurements, Recurring | Level 2 | Foreign bonds
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	289	305
Fair Value, Measurements, Recurring | Level 2 | Interest rate contracts
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	239
Total liabilities		55
Fair Value, Measurements, Recurring | Level 2 | Foreign currency contracts
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	587	816
Total liabilities	303	137
Fair Value, Measurements, Recurring | Level 2 | Other derivatives
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	5	3
Fair Value, Measurements, Recurring | Level 3
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	36	40
Fair Value, Measurements, Recurring | Level 3 | Other debt securities
Financial assets and liabilities measured at fair value on a recurring basis
Total assets	$ 36	$ 40