Income Taxes (Provision for Income Taxes Differed from Amounts Computed by the U.S. Federal Income Tax Rate) (Details) - USD ($)	12 Months Ended
Jul. 31, 2020	Jul. 31, 2019	Jul. 31, 2018
Amount
Computed "expected" tax expense	$ 1,955,000	$ 6,071,000	$ 6,615,000
State and local income taxes, net of federal benefit	(278,000)	967,000	1,193,000
Stock-based compensation	308,000	(44,000)	(1,112,000)
Research and experimentation credits	(1,210,000)	(1,129,000)	(678,000)
Foreign-derived intangible income deduction	(162,000)	(632,000)	0
Nondeductible transaction costs	301,000	394,000	0
Nondeductible executive compensation	595,000	330,000	(22,000)
Fines and penalties	189,000	2,000	1,000
Audit settlements	1,000	(2,081,000)	0
Remeasurement of deferred taxes	(135,000)	0	(11,317,000)
Foreign income taxes	453,000	5,000	(221,000)
Other, net	273,000	(14,000)	398,000
Provision for (benefit from) income taxes	$ 2,290,000	$ 3,869,000	$ (5,143,000)
Rate
Computed "expected" tax expense	21.00%	21.00%	27.00%
State and local income taxes, net of federal benefit	(3.00%)	3.30%	4.80%
Stock-based compensation	3.30%	(0.10%)	(4.50%)
Research and experimentation credits	(13.00%)	(3.90%)	(2.80%)
Foreign-derived intangible income deduction	(1.70%)	(2.20%)	0.00%
Nondeductible transaction costs	3.20%	1.40%	0.00%
Nondeductible executive compensation	6.40%	1.10%	(0.10%)
Fines and penalties	2.00%	0.00%	0.00%
Audit settlements	0.00%	(7.20%)	0.00%
Remeasurement of deferred taxes	(1.50%)	0.00%	(46.00%)
Foreign income taxes	4.90%	0.00%	(0.90%)
Other, net	3.00%	0.00%	1.50%
Provision for (benefit from) income taxes	24.60%	13.40%	(21.00%)

Effective Income Tax Rate Reconciliation Deduction, Foreign-Derived Intangible Income

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