INCOME TAXES Income Tax Effective Rate Reconciliation (Details)	5 Months Ended	7 Months Ended	12 Months Ended
	Dec. 31, 2017	Jul. 31, 2018	Jul. 31, 2019	Jul. 31, 2018
U.S. federal income tax rate	35.00%	21.00%	21.00%	26.90%
Depletion deductions allowed for mining			(8.20%)	(10.10%)
State income tax expense, net of federal tax expense			2.50%	2.50%
Difference in effective tax rate of foreign subsidiaries			0.20%	0.10%
Prior year income taxes			(1.90%)	0.20%
Change in federal tax rate applied to deferred tax assets and liabilities			0.00%	26.80%
Deduction for domestic production activities			0.00%	(1.40%)
Other			(0.30%)	(0.30%)
Effective income tax rate			13.30%	44.70%