Post Retirement Benefit Plans - Actuarial Assumptions Used for the Measurement of Benefit Obligations and Pension Costs (Detail) - Other Postretirement Benefits Plan	Oct. 31, 2018	Oct. 31, 2017
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Actuarial assumptions used to measure the year-end benefit obligations and the pension costs	5.02%	4.12%
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	4.39%	3.44%
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	10.10%	9.80%