Post Retirement Benefit Plans - Summary of Healthcare Cost Trend Rates on Gross Eligible Charges (Details) - Other Postretirement Benefits Plan	Oct. 31, 2019
Pension Plans, Postretirement and Other Employee Benefits [Line Items]
Current trend rate	6.30%
Ultimate trend rate	4.70%

Assumed rate, for next fiscal year, based on annual change in cost of health care cost benefits used to measure expected cost of benefits covered by defined benefit postretirement plan. Factors include, but are not limited to, estimate of health care inflation, change in health care utilization or delivery pattern, technological advances, and change in health status of participant. Excludes factors for change in composition of plan population by age and dependency status.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 715
-SubTopic 20
-Section 50
-Paragraph 1
-Subparagraph (l)
-URI http://asc.fasb.org/extlink&oid=118255775&loc=d3e1928-114920

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Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant