Income taxes (Tables)

12 Months Ended

Jul. 31, 2020

Income Tax Disclosure [Abstract]

Schedule of benefit for income taxes

	2020		2019		2018
Federal	$	—	$	—	$	1,097
State and local		—		—		—
Foreign		—		—		—
Deferred benefit		—		—		—
Benefit for income taxes	$	—	$	—	$	1,097

Schedule of deferred tax assets and liabilities

	2020			2019
Deferred tax assets:
Federal tax carryforward losses	$	18,173		$	12,558
Provision for uncollectible accounts receivable		1,079			1,116
State and local tax carry forward losses		1,187			144
Accrued royalties		101			101
Stock compensation		898			769
Depreciation		799			682
Research and development and other tax credit carryforwards		1,477			1,350
Lease liabilities		5,520			—
Foreign tax carryforward losses		3,357			3,783
Intangibles and goodwill		1,162			1,479
Inventory		1,156			1,086
Accrued expenses		1,176			1,127
Other, net		37			82
Deferred tax assets		36,122			24,277
Right of use assets		(5,288	)		—
Prepaid expenses		(705	)		(626	)
Other, net		(52	)		(124	)
Deferred tax liabilities		(6,045	)		(750	)
Net deferred tax assets before valuation allowance		30,077			23,527
Less: valuation allowance		(30,077	)		(23,527	)
Net deferred tax liabilities	$	—		$	—

Schedule of benefit for income taxes

	2020			2019			2018
United States operations	$	(27,690	)	$	4,618		$	(9,540	)
International operations		(830	)		(2,129	)		(1,878	)
(Loss) income before taxes	$	(28,520	)	$	2,489		$	(11,418	)

Schedule of benefit for income taxes

	2020			2019			2018
Federal statutory rate		21.0	%		(21.0	)%		26.4	%
Compensation and other expenses not deductible for income tax return purposes		(1.1	)		(15.3	)		(1.0	)
Change in valuation allowance		(19.9	)		33.6			73.9
State tax law change		—			—			—
Impact of Tax Act on valuation allowance		—			—			(100.1	)
AMT refund under Tax Act		—			—			9.6
Other					2.7			0.8
		—	%		—	%		9.6	%