Consolidated Statements of Stockholders Equity Statement - USD ($)	Total	Noncontrolling Interest	Parent	Common & Class B Stock	Additional Paid-in Capital	Retained Earnings	Treasury Stock	Accumulated Other Comprehensive Loss	Noncontrolling Interest
Total, Beginning of Period at Jul. 31, 2018	$ 131,885,000			$ 1,056,000	$ 38,473,000	$ 158,935,000	$ (55,946,000)	$ (10,615,000)	$ (18,000)
Common & Class B Stock, Beginning of Period (in shares) at Jul. 31, 2018				10,555,828
Treasury Stock, Beginning of Period (in shares) at Jul. 31, 2018							(3,238,833)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Oil-Dri	8,812,000			$ 0	0	8,812,000	$ 0	0
Net Income (Loss) Attributable to Noncontrolling Interest	(35,000)								(35,000)
Net Income, Including Portion Attributable to Noncontrolling Interest	8,777,000
Other comprehensive income	430,000			0	0	0	0	430,000	0
Dividends declared	(5,029,000)			0	0	(5,029,000)	0	0	0
Purchases of treasury stock	141,000			0	0	0	$ (141,000)	0	0
Purchases of treasury stock (in shares)							4,545
Net issuance of stock under long-term incentive plans	1,000			$ (29,000)	(420,000)	0	$ (450,000)	0	0
Net issuance of stock under long-term incentive plans (in shares)				297,600			(7,737)
Amortization of restricted stock	1,594,000			$ 0	1,594,000	0	$ 0	0	0
Total, End of Period at Apr. 30, 2019	137,515,000			$ 1,085,000	40,487,000	162,718,000	$ (56,537,000)	(10,185,000)	(53,000)
Common Stock & Class B Stock, End of Period (in shares) at Apr. 30, 2019				10,853,428
Treasury Stock, End of Period (in shares) at Apr. 30, 2019							(3,251,115)
Total, Beginning of Period at Jan. 31, 2019	132,764,000			$ 1,081,000	39,730,000	158,788,000	$ (56,480,000)	(10,360,000)	5,000
Common & Class B Stock, Beginning of Period (in shares) at Jan. 31, 2019				10,812,928
Treasury Stock, Beginning of Period (in shares) at Jan. 31, 2019							(3,249,728)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Oil-Dri	5,619,000			$ 0	0	5,619,000	$ 0	0
Net Income (Loss) Attributable to Noncontrolling Interest	(58,000)								(58,000)
Net Income, Including Portion Attributable to Noncontrolling Interest	5,561,000
Other comprehensive income	175,000			0	0	0	0	175,000	0
Dividends declared	1,689,000			0	0	(1,689,000)	0	0	0
Purchases of treasury stock	(6,000)			0	0	0	$ (6,000)	0	0
Purchases of treasury stock (in shares)							0
Net issuance of stock under long-term incentive plans	0			$ (4,000)	(47,000)	0	$ 51,000	0	0
Net issuance of stock under long-term incentive plans (in shares)				40,500			(1,387)
Amortization of restricted stock	710,000			$ 0	710,000	0	$ 0	0	0
Total, End of Period at Apr. 30, 2019	137,515,000			$ 1,085,000	40,487,000	162,718,000	$ (56,537,000)	(10,185,000)	(53,000)
Common Stock & Class B Stock, End of Period (in shares) at Apr. 30, 2019				10,853,428
Treasury Stock, End of Period (in shares) at Apr. 30, 2019							(3,251,115)
Total, Beginning of Period at Jul. 31, 2019	135,546,000			$ 1,086,000	41,300,000	164,756,000	$ (56,543,000)	(15,039,000)	(14,000)
Common & Class B Stock, Beginning of Period (in shares) at Jul. 31, 2019				10,860,678
Treasury Stock, Beginning of Period (in shares) at Jul. 31, 2019							(3,251,288)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Oil-Dri	13,014,000			$ 0	0	13,014,000	$ 0	0
Net Income (Loss) Attributable to Noncontrolling Interest	(155,000)								(155,000)
Net Income, Including Portion Attributable to Noncontrolling Interest	12,859,000
Other comprehensive income	5,444,000			0	0	0	0	5,444,000	0
Dividends declared	(5,266,000)			0	0	(5,266,000)	0	0	0
Purchases of treasury stock	4,620,000			0	0	0	$ (4,620,000)	0	0
Purchases of treasury stock (in shares)							143,391
Net issuance of stock under long-term incentive plans	(1,000)			$ (2,000)	(158,000)	0	$ 159,000	0	0
Net issuance of stock under long-term incentive plans (in shares)				22,477			(4,950)
Amortization of restricted stock	2,549,000			$ 0	2,549,000	0	$ 0	0	0
Contributions from noncontrolling interests	142,000			0	142,000	0	0	0	0
Total, End of Period at Apr. 30, 2020	146,655,000			$ 1,088,000	44,149,000	172,504,000	$ (61,322,000)	(9,595,000)	(169,000)
Common Stock & Class B Stock, End of Period (in shares) at Apr. 30, 2020				10,883,155
Treasury Stock, End of Period (in shares) at Apr. 30, 2020							(3,399,629)
Noncontrolling Interest
Amount Contributed to Purchase of Additional Interest by Parent			$ 724,000
Total, Beginning of Period at Jan. 31, 2020	146,929,000			$ 1,088,000	43,149,000	169,590,000	$ (57,138,000)	(9,589,000)	(171,000)
Common & Class B Stock, Beginning of Period (in shares) at Jan. 31, 2020				10,881,155
Treasury Stock, Beginning of Period (in shares) at Jan. 31, 2020							(3,269,059)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net Income Attributable to Oil-Dri	4,648,000			$ 0	0	4,648,000	$ 0	0
Net Income (Loss) Attributable to Noncontrolling Interest	2,000								2,000
Net Income, Including Portion Attributable to Noncontrolling Interest	4,650,000
Other comprehensive income	(6,000)			0	0	0	0	(6,000)	0
Dividends declared	1,734,000			0	0	(1,734,000)	0	0	0
Purchases of treasury stock	(4,097,000)			0	0	0	$ (4,097,000)	0	0
Purchases of treasury stock (in shares)							127,770
Net issuance of stock under long-term incentive plans	(1,000)			$ 0	(88,000)	0	$ 87,000	0	0
Net issuance of stock under long-term incentive plans (in shares)				2,000			(2,800)
Amortization of restricted stock	770,000			$ 0	770,000	0	$ 0	0	0
Contributions from noncontrolling interests	142,000			0	142,000	0	0	0	0
Total, End of Period at Apr. 30, 2020	$ 146,655,000			$ 1,088,000	$ 44,149,000	$ 172,504,000	$ (61,322,000)	$ (9,595,000)	$ (169,000)
Common Stock & Class B Stock, End of Period (in shares) at Apr. 30, 2020				10,883,155
Treasury Stock, End of Period (in shares) at Apr. 30, 2020							(3,399,629)
Noncontrolling Interest
Noncontrolling Interest, Parent Ownership Percentage Prior to Purchase of Additional Interest			52.00%
Noncontrolling Interest, Ownership Percentage by Parent			78.40%
Noncontrolling Interest, Ownership Percentage Prior to Parent's Purchase of Additional Interest		48.00%
Noncontrolling Interest, Ownership Percentage by Noncontrolling Owners		21.60%