Shareholders' Equity, Reconciliation of Changes in Shareholders' Equity (Details) - USD ($) $ in Thousands	3 Months Ended
Oct. 27, 2018	Oct. 28, 2017	Jul. 31, 2018
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	$ 36,447
Net (loss) income	(115)	$ 688
Foreign currency translation adjustments	(127)	(14)
Unrealized investment losses, net	0	(3)
Balance	36,261
Common Stock [Member] \| Class A Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	30	30
Balance (Adjusted)	30
Net (loss) income	0	0
Foreign currency translation adjustments	0	0
Conversion of Class B common stock to Class A common stock	1
Issuance of stock under stock award plan	0
Unrealized investment losses, net		0
Share-based compensation expense	0	0
Distributions to noncontrolling interests	0	0
Balance	31	30
Common Stock [Member] \| Class A Common Stock [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			$ 0
Common Stock [Member] \| Class B Common Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	14	14
Balance (Adjusted)	14
Net (loss) income	0	0
Foreign currency translation adjustments	0	0
Conversion of Class B common stock to Class A common stock	(1)
Issuance of stock under stock award plan	0
Unrealized investment losses, net		0
Share-based compensation expense	0	0
Distributions to noncontrolling interests	0	0
Balance	13	14
Common Stock [Member] \| Class B Common Stock [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			0
Capital in Excess of Par Value [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	17,558	17,570
Balance (Adjusted)	17,558
Net (loss) income	0	0
Foreign currency translation adjustments	0	0
Conversion of Class B common stock to Class A common stock	0
Issuance of stock under stock award plan	4
Unrealized investment losses, net		0
Share-based compensation expense	33	47
Distributions to noncontrolling interests	0	0
Balance	17,595	17,617
Capital in Excess of Par Value [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			0
Retained Earnings [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	20,973	23,005
Balance (Adjusted)	20,968
Net (loss) income	(120)	588
Foreign currency translation adjustments	0	0
Conversion of Class B common stock to Class A common stock	0
Issuance of stock under stock award plan	0
Unrealized investment losses, net		0
Share-based compensation expense	0	0
Distributions to noncontrolling interests	0	0
Balance	20,848	23,593
Retained Earnings [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			(5)
Accumulated Other Comprehensive Income (Loss) [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(1,885)	(1,795)
Balance (Adjusted)	(1,880)
Net (loss) income	0	0
Foreign currency translation adjustments	(67)	(8)
Conversion of Class B common stock to Class A common stock	0
Issuance of stock under stock award plan	0
Unrealized investment losses, net		(3)
Share-based compensation expense	0	0
Distributions to noncontrolling interests	0	0
Balance	(1,947)	(1,806)
Accumulated Other Comprehensive Income (Loss) [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			5
Treasury Stock [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	(907)	(1,037)
Balance (Adjusted)	(907)
Net (loss) income	0	0
Foreign currency translation adjustments	0	0
Conversion of Class B common stock to Class A common stock	0
Issuance of stock under stock award plan	23
Unrealized investment losses, net		0
Share-based compensation expense	0	0
Distributions to noncontrolling interests	0	0
Balance	(884)	(1,037)
Treasury Stock [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			0
Noncontrolling Interest [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Balance	664	947
Balance (Adjusted)	664
Net (loss) income	5	100
Foreign currency translation adjustments	(60)	(6)
Conversion of Class B common stock to Class A common stock	0
Issuance of stock under stock award plan	0
Unrealized investment losses, net		0
Share-based compensation expense	0	0
Distributions to noncontrolling interests	(4)	(49)
Balance	$ 605	$ 992
Noncontrolling Interest [Member] \| ASU 2016-01 [Member]
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Cumulative effect of adoption			$ 0

Amount of increase to additional paid-in capital (APIC) from recognition of equity-based compensation.

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