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, 2014	$ 27	$ 17	$ 17,124	$ 21,917	$ (183)	$ (1,224)	$ 4,114
Balance (in shares) at Jul. 31, 2014	2,685,151	1,708,574				105,354
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	$ 0	0	3,396	0	$ 0	804	$ 4,200
Foreign currency translation adjustment	0	0	0	0	(1,540)	0	(611)	(2,152)
Cash dividends declared	0	0	0	(2,067)	0	0	0	(2,067)
Unrealized investment gain (loss), net	0	0	0	0	(3)	0	0	(4)
Conversion of Class B common stock to Class A common stock	$ 3	$ (3)	0	0	0	0	0
Conversion of Class B common stock to Class A common stock (in shares)	338,055	(338,055)
Share-based compensation expense	$ 0	$ 0	59	0	0	0	0
Tax impact of share based compensation	0	0	(92)	0	0	0	0
Tax impact of noncontrolling interests	0	0	(428)	0	0	0	0
Distributions to noncontrolling interests	0	0	0	0	0	0	(537)
Purchase of additional noncontrolling interests	0	0	(88)	0	0	0	(200)
Stock award plan forfeitures	0	0	0	0	0	$ 0	0
Stock award plan forfeitures (in shares)						1,692
Balance at Jul. 31, 2015	$ 30	$ 14	16,575	23,246	(1,726)	$ (1,224)	3,570
Balance (in shares) at Jul. 31, 2015	3,023,206	1,370,519				107,046
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income (loss)	$ 0	$ 0	0	886	0	$ 0	(278)	608
Foreign currency translation adjustment	0	0	0	0	(438)	0	(119)	(557)
Cash dividends declared	0	0	0	(1,895)	0	0	0	(1,895)
Unrealized investment gain (loss), net	0	0	0	0	21	0	0	21
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)	12,572	(12,572)
Issuance of stock under stock award plan	$ 0	$ 0	(6)	0	0	$ 52	0
Issuance of stock under stock award plan (in shares)						(4,533)
Share-based compensation expense	0	0	37	0	0	$ 0	0
Distributions to noncontrolling interests	0	0	0	0	0	0	(530)
Sale of majority-owned subsidiary	0	0	0	0	0	0	(310)
Stock award plan forfeitures	0	0	0	0	0	$ 0	0
Stock award plan forfeitures (in shares)						1,560
Balance at Jul. 31, 2016	$ 30	$ 14	16,606	22,237	(2,143)	$ (1,172)	2,333	37,905
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)	2,953
Foreign currency translation adjustment	0	0	0	0	143	0	87	230
Cash dividends declared	0	0	0	(1,719)	0	0	0	(1,719)
Unrealized investment gain (loss), net	0	0	0	0	(18)	0	0	(18)
Issuance of stock under stock award plan	0	0	4	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	(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