Consolidated Statements of Changes in Shareholders Equity - USD ($) $ in Thousands	Common Stock [Member] Class A [Member]	Common Stock [Member] Class B [Member]	Capital in Excess of Par Value [Member]	Retained Earnings [Member]	Accumulated Other Comprehensive Income (Loss) [Member]	Treasury Stock [Member]	Noncontrolling Interest [Member]	Total
Balance at Jul. 31, 2016	$ 30	$ 14	$ 17,666	$ 21,925	$ (1,929)	$ (1,172)	$ 1,221
Balance (in shares) at Jul. 31, 2016	3,035,778	1,357,947				104,073
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	$ 0	0	2,823	0	$ 0	(312)	$ 2,511
Foreign currency translation adjustments	0	0	0	0	152	0	22	174
Cash dividends declared	0	0	0	(1,719)	0	0	0	(1,719)
Unrealized investment losses, net	0	0	0	0	(18)	0	0	(18)
Issuance of stock under stock award plan	0	0	(90)	0	0	$ 135	0
Issuance of stock under stock award plan (in shares)						(11,952)
Tax impact of share based compensation	0	0	(6)	0	0	$ 0	0
Tax impact of noncontrolling interests	0	0	0	(24)	0	0	24
Distributions to noncontrolling interests	0	0	0	0	0	0	(8)
Balance at Jul. 31, 2017	$ 30	$ 14	17,570	23,005	(1,795)	$ (1,037)	947
Balance (in shares) at Jul. 31, 2017	3,035,778	1,357,947				92,121
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	$ 0	0	(308)	0	$ 0	204	(104)
Foreign currency translation adjustments	0	0	0	0	(70)	0	(15)	(85)
Cash dividends declared	0	0	0	(1,724)	0	0	0	(1,724)
Unrealized investment losses, net	0	0	0	0	(20)	0	0	(20)
Conversion of Class B common stock to Class A common stock	$ 0	$ 0	0	0	0	0	0
Conversion of Class B common stock to Class A common stock (in shares)	6,133	(6,133)
Issuance of stock under stock award plan	$ 0	$ 0	(130)	0	0	$ 130	0
Issuance of stock under stock award plan (in shares)						(11,531)
Share-based compensation expense	0	0	127	0	0	$ 0	0
Distributions to noncontrolling interests	0	0	0	0	0	0	(455)
Sale of majority-owned subsidiary shares to noncontrolling interests	0	0	(9)	0	0	0	0
Purchase of additional noncontrolling interests	0	0	0	0	0	0	(17)
Balance at Jul. 31, 2018	30	14	17,558	20,973	(1,885)	(907)	664	36,447
Balance at Jul. 31, 2018	$ 30	$ 14	17,558	20,968	(1,880)	$ (907)	664
Balance (in shares) at Jul. 31, 2018	3,041,911	1,351,814				80,590
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption of ASU 2016-01 | ASU 2016-01 [Member]	$ 0	$ 0	0	(5)	5	$ 0	0
Net income (loss)	0	0	0	(554)	0	0	444	(110)
Foreign currency translation adjustments	0	0	0	0	(218)	0	(55)	(273)
Cash dividends declared	0	0	0	(1,727)	0	0	0	(1,728)
Unrealized investment losses, net								0
Conversion of Class B common stock to Class A common stock	$ 2	$ (2)	0	0	0	0	0
Conversion of Class B common stock to Class A common stock (in shares)	151,079	(151,079)
Issuance of stock under stock award plan	$ 0	$ 0	(102)	0	0	$ 178	0
Issuance of stock under stock award plan (in shares)						(15,767)
Share-based compensation expense	0	0	100	0	0	$ 0	0
Distributions to noncontrolling interests	0	0	0	0	0	0	(299)
Sale of majority-owned subsidiary shares to noncontrolling interests	0	0	(598)	0	0	0	0
Adjustment to investment in Brazil	0	0	(240)	0	0	0	0
Purchase of additional noncontrolling interests	0	0	246	0	0	0	153
Balance at Jul. 31, 2019	$ 32	$ 12	$ 16,964	$ 18,687	$ (2,098)	$ (729)	$ 907	$ 33,775
Balance (in shares) at Jul. 31, 2019	3,192,990	1,200,735				64,823