Retirement and Post-Retirement Benefit Plans (Details) (USD $) In Millions, unless otherwise specified	94 Months Ended
	Oct. 31, 2013	Oct. 31, 2012	Oct. 31, 2011
Retirement and post-retirement benefit plans
Plan assets	$ 11,703	$ 12,494
Projected Benefit Obligation	12,703	15,195
U.S. Defined Benefit Plans
Retirement and post-retirement benefit plans
Plan assets	10,866	11,536
Projected Benefit Obligation	11,866	14,237	11,945
Post-Retirement Benefit Plans
Retirement and post-retirement benefit plans
Projected Benefit Obligation	867	1,056	816
Age for eligibility under HP Retirement Medical Savings Account Plan	45 years
DPSP
Retirement and post-retirement benefit plans
Plan assets	837	958
Projected Benefit Obligation	$ 837	$ 958