PENSION AND OTHER POSTRETIREMENT BENEFITS Fair value level of pension plan assets (Details) - USD ($)	12 Months Ended
	Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Equity securities - international mutual funds: Developed market
Defined Benefit Plan Disclosure
Minimum % of Fund Assets Invested in Non-US Stocks Developed Market	80.00%	80.00%
Fixed Income: Government sponsored entities
Defined Benefit Plan Disclosure
Amount Backed by US Government	$ 289,000	$ 377,000
Fixed Income: Multi-strategy bond fund [Member] | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount		0
Pension Benefits
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	45,334,000	40,725,000	$ 40,971,000
Pension Benefits | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	3,145,000	6,822,000
Pension Benefits | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	42,189,000	33,903,000
Pension Benefits | Cash and Cash Equivalents
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	557,000	66,000
Pension Benefits | Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	557,000	66,000
Pension Benefits | Cash and Cash Equivalents | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Equity securities U.S. companies
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	9,401,000	13,775,000
Pension Benefits | Equity securities U.S. companies | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,093,000	4,147,000
Pension Benefits | Equity securities U.S. companies | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	7,308,000	9,628,000
Pension Benefits | Equity securities International companies
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	495,000	2,609,000
Pension Benefits | Equity securities International companies | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	495,000	2,609,000
Pension Benefits | Equity securities International companies | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Equity securities - international mutual funds: Developed market
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,867,000	5,275,000
Pension Benefits | Equity securities - international mutual funds: Developed market | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Equity securities - international mutual funds: Developed market | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,867,000	5,275,000
Pension Benefits | Equity securities - international mutual funds: Emerging market
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	1,022,000	1,141,000
Pension Benefits | Equity securities - international mutual funds: Emerging market | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Equity securities - international mutual funds: Emerging market | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	1,022,000	1,141,000
Pension Benefits | Commodity Based Investments
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	637,000
Pension Benefits | Commodity Based Investments | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Commodity Based Investments | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	637,000
Pension Benefits | Fixed Income: U.S. Treasuries
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	3,014,000	3,273,000
Pension Benefits | Fixed Income: U.S. Treasuries | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Fixed Income: U.S. Treasuries | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	3,014,000	3,273,000
Pension Benefits | Fixed Income: Debt securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	10,131,000	8,103,000
Pension Benefits | Fixed Income: Debt securities | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Fixed Income: Debt securities | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	10,131,000	8,103,000
Pension Benefits | Fixed Income: Government sponsored entities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	5,131,000	2,087,000
Pension Benefits | Fixed Income: Government sponsored entities | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Fixed Income: Government sponsored entities | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	5,131,000	2,087,000
Pension Benefits | Fixed Income: Multi-strategy bond fund [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	10,547,000	813,000
Pension Benefits | Fixed Income: Multi-strategy bond fund [Member] | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0
Pension Benefits | Fixed Income: Multi-strategy bond fund [Member] | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	10,547,000	813,000
Pension Benefits | Money Market Funds
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	486,000	557,000
Pension Benefits | Money Market Funds | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Money Market Funds | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	486,000	557,000
Pension Benefits | Other
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	1,683,000	2,389,000
Pension Benefits | Other | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	0	0
Pension Benefits | Other | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	$ 1,683,000	$ 2,389,000