Post Retirement Benefit Plans - Actuarial Assumptions Used for the Measurement of Benefit Obligations and Pension Costs (Detail) - Other Postretirement Benefits Plan	Oct. 31, 2017	Oct. 31, 2016
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Actuarial assumptions used to measure the year-end benefit obligations and the pension costs	4.12%	4.10%
United States
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Actuarial assumptions used to measure the year-end benefit obligations and the pension costs	3.44%	3.38%
South Africa
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Actuarial assumptions used to measure the year-end benefit obligations and the pension costs	9.80%	9.50%