Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited) - 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	$ 16,606	$ 22,237	$ (2,143)	$ (1,172)	$ 2,333
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	3,015	0	$ 0	(62)
Foreign currency translation adjustment	0	0	0	0	143	0	87
Cash dividends declared	0	0	0	(1,719)	0	0	0
Unrealized investment losses, net	0	0	0	0	(18)	0	0
Issuance of stock under stock award plan	$ 0	$ 0	4	0	0	$ 135	0
Issuance of stock under stock award plan (in shares)	0	0				(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	(680)
Adjustment to deferred income taxes related to acquisition of noncontrolling interests in prior years	0	0	1,004	0	0	0	0
Balance at Jul. 31, 2017	$ 30	$ 14	17,608	23,509	(2,018)	$ (1,037)	1,702	$ 39,808
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	(71)	0	$ 0	530	459
Foreign currency translation adjustment	0	0	0	0	121	0	73	194
Cash dividends declared	0	0	0	(860)	0	0	0	(860)
Unrealized investment losses, net	0	0	0	0	(26)	0	0	(26)
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)	2,137	(2,137)				0
Distributions to noncontrolling interests	$ 0	$ 0	0	0	0	$ 0	(322)
Balance at Apr. 28, 2018	$ 30	$ 14	$ 17,608	$ 22,578	$ (1,923)	$ (1,037)	$ 1,983	$ 39,253
Balance (in shares) at Apr. 28, 2018	3,037,915	1,355,810				92,121