PENSION AND OTHER POSTRETIREMENT BENEFITS Fair value level of pension plan assets (Details) - USD ($)	12 Months Ended
	Jul. 31, 2019	Jul. 31, 2018	Jul. 31, 2017
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	$ 377,000	$ 443,000
Pension Benefits
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	40,725,000	40,971,000	$ 27,457,000
Pension Benefits | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	6,822,000	9,778,000
Pension Benefits | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	33,903,000	31,193,000
Pension Benefits | Cash and Cash Equivalents
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	66,000	1,102,000
Pension Benefits | Cash and Cash Equivalents | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	66,000	1,102,000
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	13,775,000	14,253,000
Pension Benefits | Equity securities U.S. companies | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	4,147,000	5,519,000
Pension Benefits | Equity securities U.S. companies | Level 2
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	9,628,000	8,734,000
Pension Benefits | Equity securities International companies
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,609,000	3,157,000
Pension Benefits | Equity securities International companies | Level 1
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,609,000	3,157,000
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	5,275,000	5,851,000
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	5,275,000	5,851,000
Pension Benefits | Equity securities - international mutual funds: Emerging market
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	1,141,000	905,000
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	1,141,000	905,000
Pension Benefits | Commodity Based Investments
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	637,000	687,000
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	637,000	687,000
Pension Benefits | Fixed Income: U.S. Treasuries
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	3,273,000	1,929,000
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	3,273,000	1,929,000
Pension Benefits | Fixed Income: Debt securities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	8,103,000	8,325,000
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	8,103,000	8,325,000
Pension Benefits | Fixed Income: Government sponsored entities
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,087,000	1,814,000
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	2,087,000	1,814,000
Pension Benefits | Fixed Income: Multi-strategy bond fund [Member]
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	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	813,000
Pension Benefits | Money Market Funds
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	557,000	1,567,000
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	557,000	1,567,000
Pension Benefits | Other
Defined Benefit Plan Disclosure
Defined Benefit Plan, Plan Assets, Amount	2,389,000	1,381,000
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	$ 2,389,000	$ 1,381,000