Stock-Based Compensation - Schedule of Stock Options Activity (Details) $ / shares in Units, shares in Thousands, $ in Millions	9 Months Ended
	Jul. 31, 2016 USD ($) $ / shares shares
Shares
Outstanding at beginning of period (shares) | shares	36,278
Granted (shares) | shares	25,424
Exercised (shares) | shares	(3,901)
Cancelled Awards (shares) | shares	(26,252)
Forfeited and expired (shares) | shares	(2,173)
Outstanding at end of period (shares) | shares	29,376
Vested and expected to vest at end of period (shares) | shares	27,680
Exercisable at end of period (shares) | shares	15,461
Weighted- Average Exercise Price
Outstanding at beginning of period (usd per share) | $ / shares	$ 26
Granted (usd per share) | $ / shares	6
Exercised (usd per share) | $ / shares	8
Cancelled Awards (usd per share) | $ / shares	26
Forfeited and expired (usd per share) | $ / shares	16
Outstanding at end of period (usd per share) | $ / shares	12
Vested and expected to vest at end of period (usd per share) | $ / shares	12
Exercisable at end of period (usd per share) | $ / shares	$ 11
Weighted- Average Remaining Contractual Term
Outstanding at end of period	5 years 2 months 12 days
Vested and expected to vest at end of period	5 years 1 month 6 days
Exercisable at end of period	3 years 8 months 12 days
Aggregate Intrinsic Value
Outstanding at end of period | $	$ 66
Vested and expected to vest at end of period | $	65
Exercisable at end of period | $	$ 58