Borrowings (Details 2) (USD $) In Millions, unless otherwise specified	6 Months Ended	12 Months Ended
	Apr. 30, 2012	Oct. 31, 2011
Long-term debt
Fair value adjustment related to hedged debt	$ 463	$ 543
Less: current portion	(3,346)	(4,345)
Total long-term debt	25,825	22,551
U.S. Dollar Global Notes
Long-term debt
Balance outstanding	26,578	24,082
2002 Shelf Registration Statement-$500 issued at discount to par at a price of 99.505% in June 2002 at 6.5%, due July 2012
Long-term debt
Balance outstanding	500	500
Discount to par (as a percent)	99.505%	99.505%
Interest rate (as a percent)	6.50%	6.50%
Face amount of debt instrument	500	500
2006 Shelf Registration Statement-$600 issued at par in February 2007 at three-month USD LIBOR plus 0.11%, paid March 2012
Long-term debt
Balance outstanding		600
Face amount of debt instrument		600
Reference interest rate		three-month USD LIBOR
Spread on reference interest rate (as a percent)		0.11%
2006 Shelf Registration Statement-$900 issued at discount to par at a price of 99.938% in February 2007 at 5.25%, paid March 2012
Long-term debt
Balance outstanding		900
Discount to par (as a percent)		99.938%
Interest rate (as a percent)		5.25%
Face amount of debt instrument		900
2006 Shelf Registration Statement-$500 issued at discount to par at a price of 99.694% in February 2007 at 5.4%, due March 2017
Long-term debt
Balance outstanding	499	499
Discount to par (as a percent)	99.694%	99.694%
Interest rate (as a percent)	5.40%	5.40%
Face amount of debt instrument	500	500
2006 Shelf Registration Statement-$1,500 issued at discount to par at a price of 99.921% in March 2008 at 4.5%, due March 2013
Long-term debt
Balance outstanding	1,500	1,500
Discount to par (as a percent)	99.921%	99.921%
Interest rate (as a percent)	4.50%	4.50%
Face amount of debt instrument	1,500	1,500
2006 Shelf Registration Statement-$750 issued at discount to par at a price of 99.932% in March 2008 at 5.5%, due March 2018
Long-term debt
Balance outstanding	750	750
Discount to par (as a percent)	99.932%	99.932%
Interest rate (as a percent)	5.50%	5.50%
Face amount of debt instrument	750	750
2006 Shelf Registration Statement-$2,000 issued at discount to par at a price of 99.561% in December 2008 at 6.125%, due March 2014
Long-term debt
Balance outstanding	1,997	1,996
Discount to par (as a percent)	99.561%	99.561%
Interest rate (as a percent)	6.125%	6.125%
Face amount of debt instrument	2,000	2,000
2006 Shelf Registration Statement-$1,000 issued at discount to par at a price of 99.956% in February 2009 at 4.25%, paid February 2012
Long-term debt
Balance outstanding		1,000
Discount to par (as a percent)		99.956%
Interest rate (as a percent)		4.25%
Face amount of debt instrument		1,000
2006 Shelf Registration Statement-$1,500 issued at discount to par at a price of 99.993% in February 2009 at 4.75%, due June 2014
Long-term debt
Balance outstanding	1,500	1,500
Discount to par (as a percent)	99.993%	99.993%
Interest rate (as a percent)	4.75%	4.75%
Face amount of debt instrument	1,500	1,500
2009 Shelf Registration Statement-$250 issued at discount to par at a price of 99.984% in May 2009 at 2.95%, due August 2012
Long-term debt
Balance outstanding	250	250
Discount to par (as a percent)	99.984%	99.984%
Interest rate (as a percent)	2.95%	2.95%
Face amount of debt instrument	250	250
2009 Shelf Registration Statement-$800 issued at par in September 2010 at three-month USD LIBOR plus 0.125%, due September 2012
Long-term debt
Balance outstanding	800	800
Face amount of debt instrument	800	800
Reference interest rate	three-month USD LIBOR	three-month USD LIBOR
Spread on reference interest rate (as a percent)	0.125%	0.125%
2009 Shelf Registration Statement-$1,100 issued at discount to par at a price of 99.921% in September 2010 at 1.25% due September 2013
Long-term debt
Balance outstanding	1,100	1,099
Discount to par (as a percent)	99.921%	99.921%
Interest rate (as a percent)	1.25%	1.25%
Face amount of debt instrument	1,100	1,100
2009 Shelf Registration Statement-$1,100 issued at discount to par at a price of 99.887% in September 2010 at 2.125% due September 2015
Long-term debt
Balance outstanding	1,099	1,099
Discount to par (as a percent)	99.887%	99.887%
Interest rate (as a percent)	2.125%	2.125%
Face amount of debt instrument	1,100	1,100
2009 Shelf Registration Statement-$650 issued at discount to par at a price of 99.911% in December 2010 at 2.2% due December 2015
Long-term debt
Balance outstanding	650	650
Discount to par (as a percent)	99.911%	99.911%
Interest rate (as a percent)	2.20%	2.20%
Face amount of debt instrument	650	650
2009 Shelf Registration Statement-$1,350 issued at discount to par at a price of 99.827% in December 2010 at 3.75% due December 2020
Long-term debt
Balance outstanding	1,348	1,348
Discount to par (as a percent)	99.827%	99.827%
Interest rate (as a percent)	3.75%	3.75%
Face amount of debt instrument	1,350	1,350
2009 Shelf Registration Statement-$1,750 issued at par in May 2011 at three month USD LIBOR plus 0.28%, due May 2013
Long-term debt
Balance outstanding	1,750	1,750
Face amount of debt instrument	1,750	1,750
Reference interest rate	three-month USD LIBOR	three-month USD LIBOR
Spread on reference interest rate (as a percent)	0.28%	0.28%
2009 Shelf Registration Statement-$500 issued at par in May 2011 at three month USD LIBOR plus 0.4%, due May 2014
Long-term debt
Balance outstanding	500	500
Face amount of debt instrument	500	500
Reference interest rate	three-month USD LIBOR	three-month USD LIBOR
Spread on reference interest rate (as a percent)	0.40%	0.40%
2009 Shelf Registration Statement-$500 issued at discount to par at a price of 99.971% in May 2011 at 1.55%, due May 2014
Long-term debt
Balance outstanding	500	500
Discount to par (as a percent)	99.971%	99.971%
Interest rate (as a percent)	1.55%	1.55%
Face amount of debt instrument	500	500
2009 Shelf Registration Statement-$1,000 issued at discount to par at a price of 99.958% in May 2011 at 2.65%, due June 2016
Long-term debt
Balance outstanding	1,000	1,000
Discount to par (as a percent)	99.958%	99.958%
Interest rate (as a percent)	2.65%	2.65%
Face amount of debt instrument	1,000	1,000
2009 Shelf Registration Statement-$1,250 issued at discount to par at a price of 99.799% in May 2011 at 4.3%, due June 2021
Long-term debt
Balance outstanding	1,248	1,248
Discount to par (as a percent)	99.799%	99.799%
Interest rate (as a percent)	4.30%	4.30%
Face amount of debt instrument	1,250	1,250
2009 Shelf Registration Statement-$750 issued at discount to par at a price of 99.977% in September 2011 at 2.35%, due March 2015
Long-term debt
Balance outstanding	750	750
Discount to par (as a percent)	99.977%	99.977%
Interest rate (as a percent)	2.35%	2.35%
Face amount of debt instrument	750	750
2009 Shelf Registration Statement-$1,300 issued at discount to par at a price of 99.784% in September 2011 at 3.0%, due September 2016
Long-term debt
Balance outstanding	1,298	1,297
Discount to par (as a percent)	99.784%	99.784%
Interest rate (as a percent)	3.00%	3.00%
Face amount of debt instrument	1,300	1,300
2009 Shelf Registration Statement-$1,000 issued at discount to par at a price of 99.816% in September 2011 at 4.375%, due September 2021
Long-term debt
Balance outstanding	998	998
Discount to par (as a percent)	99.816%	99.816%
Interest rate (as a percent)	4.375%	4.375%
Face amount of debt instrument	1,000	1,000
2009 Shelf Registration Statement-$1,200 issued at discount to par at a price of 99.863% in September 2011 at 6.0% due September 2041
Long-term debt
Balance outstanding	1,198	1,198
Discount to par (as a percent)	99.863%	99.863%
Interest rate (as a percent)	6.00%	6.00%
Face amount of debt instrument	1,200	1,200
2009 Shelf Registration Statement-$350 issued at par in September 2011 at three month USD LIBOR plus 1.55%, due September 2014
Long-term debt
Balance outstanding	350	350
Face amount of debt instrument	350	350
Reference interest rate	three-month USD LIBOR	three-month USD LIBOR
Spread on reference interest rate (as a percent)	1.55%	1.55%
2009 Shelf Registration Statement-$650 issued at discount to par at a price of 99.946% in December 2011 at 2.625%, due December 2014
Long-term debt
Balance outstanding	650
Discount to par (as a percent)	99.946%
Interest rate (as a percent)	2.625%
Face amount of debt instrument	650
2009 Shelf Registration Statement-$850 issued at discount to par at a price of 99.790% in December 2011 at 3.3%, due December 2016
Long-term debt
Balance outstanding	848
Discount to par (as a percent)	99.79%
Interest rate (as a percent)	3.30%
Face amount of debt instrument	850
2009 Shelf Registration Statement-$1,500 issued at discount to par at a price of 99.707% in December 2011 at 4.65%, due December 2021
Long-term debt
Balance outstanding	1,496
Discount to par (as a percent)	99.707%
Interest rate (as a percent)	4.65%
Face amount of debt instrument	1,500
2009 Shelf Registration Statement-$1,500 issued at discount to par at a price of 99.985% in March 2012 at 2.6%, due September 2017
Long-term debt
Balance outstanding	1,500
Discount to par (as a percent)	99.985%
Interest rate (as a percent)	2.60%
Face amount of debt instrument	1,500
2009 Shelf Registration Statement-$500 issued at discount to par at a price of 99.771% in March 2012 at 4.05%, due September 2022
Long-term debt
Balance outstanding	499
Discount to par (as a percent)	99.771%
Interest rate (as a percent)	4.05%
Face amount of debt instrument	500
EDS Senior Notes
Long-term debt
Balance outstanding	1,428	1,435
EDS Senior Notes-$1,100 issued June 2003 at 6.0%, due August 2013
Long-term debt
Balance outstanding	1,114	1,120
Interest rate (as a percent)	6.00%	6.00%
Face amount of debt instrument	1,100	1,100
EDS Senior Notes-$300 issued October 1999 at 7.45%, due October 2029
Long-term debt
Balance outstanding	314	315
Interest rate (as a percent)	7.45%	7.45%
Face amount of debt instrument	300	300
Other, including capital lease obligations, at 0.60%-8.63%, due in calendar years 2012-2024
Long-term debt
Other, including capital lease obligations	702	836
Minimum interest rate (as a percent)	0.60%	0.60%
Maximum interest rate (as a percent)	8.63%	8.63%
Borrowings collateralized by certain financing receivable assets	$ 215