Retirement and Post-Retirement Benefit Plans (Details 2) (USD $) In Millions, unless otherwise specified	12 Months Ended			31 Months Ended	12 Months Ended	31 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009	Oct. 31, 2011 HP 401(k) Plan	Oct. 31, 2008 EDS 401(k) Plan through Dec 2010	Oct. 31, 2011 EDS 401(k) Plan through Dec 2010
Defined Contribution Plan Disclosures
Total defined contribution expense	$ 626	$ 535	$ 568
Percent 401(k) match based on a maximum contribution of 6% of the employee's salary (as a percent)					25.00%
401(k) match based on maximum salary contribution to plan percentage (as a percent)					6.00%
Maximum percent 401(k) match to employees (as a percent)				4.00%		4.00%
Dividends paid on shares held by the HP Stock Fund	$ 8	$ 7	$ 8
Number of shares of common stock held by the HP Stock Fund (in shares)	21