Retirement, pension and other postretirement plans (Details 4)	12 Months Ended
	Oct. 31, 2011	Oct. 31, 2010	Oct. 31, 2009
Pension plan, United States [Member]
Assumptions used to determine benefit obligations at October 31:
Discount rate	4.46%	5.21%	5.50%
Rate of compensation increase	3.20%	3.30%	3.30%
Assumptions used to determine net benefit costs for the years ended October 31:
Discount rate	5.21%	5.50%	8.00%
Expected return on plan assets	8.25%	8.51%	8.48%
Rate of compensation increase	3.30%	3.30%	3.30%
Pension plan International [Member]
Assumptions used to determine benefit obligations at October 31:
Discount rate	4.43%	4.17%	4.78%
Rate of compensation increase	3.16%	3.21%	2.86%
Assumptions used to determine net benefit costs for the years ended October 31:
Discount rate	4.17%	4.78%	5.87%
Expected return on plan assets	4.84%	4.85%	5.04%
Rate of compensation increase	3.21%	2.86%	3.45%