Operating Segments Disaggregation of Revenue (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jan. 31, 2022	Jan. 31, 2021	Jan. 31, 2022	Jan. 31, 2021
Revenue by Principal Product
Net Sales	$ 87,210	$ 74,500	$ 169,670	$ 150,597
Business to Business Products
Revenue by Principal Product
Net Sales	32,624	26,283	61,553	53,805
Business to Business Products | Cat Litter
Revenue by Principal Product
Net Sales	4,691	3,736	9,327	7,612
Business to Business Products | Industrial and Sports
Revenue by Principal Product
Net Sales	0	0	0	0
Business to Business Products | Agricultural and Horticultural
Revenue by Principal Product
Net Sales	7,311	5,046	13,519	12,033
Business to Business Products | Bleaching Clay and Fluids Purification
Revenue by Principal Product
Net Sales	15,035	12,765	29,540	25,406
Business to Business Products | Animal Health and Nutrition
Revenue by Principal Product
Net Sales	5,587	4,736	9,167	8,754
Retail and Wholesale Products
Revenue by Principal Product
Net Sales	54,586	48,217	108,117	96,792
Retail and Wholesale Products | Cat Litter
Revenue by Principal Product
Net Sales	45,246	41,085	89,141	81,879
Retail and Wholesale Products | Industrial and Sports
Revenue by Principal Product
Net Sales	8,820	6,710	17,940	13,972
Retail and Wholesale Products | Agricultural and Horticultural
Revenue by Principal Product
Net Sales	0	0	0	0
Retail and Wholesale Products | Bleaching Clay and Fluids Purification
Revenue by Principal Product
Net Sales	520	422	1,036	941
Retail and Wholesale Products | Animal Health and Nutrition
Revenue by Principal Product
Net Sales	$ 0	$ 0	$ 0	$ 0