Goodwill and intangible assets (Tables)

12 Months Ended

Jul. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of indefinite-lived intangible assets

	Gross			Accumulated Amortization			Net
July 31, 2018	$	27,347		$	(25,461	)	$	1,886
Amortization expense		—			(842	)		(842	)
Foreign currency translation		(109	)		97			(12	)
July 31, 2019	$	27,238		$	(26,206	)	$	1,032
Amortization expense		—			(524	)		(524	)
Foreign currency translation		448			(418	)		30
July 31, 2020	$	27,686		$	(27,148	)	$	538

Schedule of intangible assets

	July 31, 2020							July 31, 2019
	Gross		Accumulated Amortization			Net		Gross		Accumulated Amortization			Net
Patents	$	11,027		(11,014	)	$	13	$	11,027	$	(10,996	)	$	31
Customer relationships		12,003		(11,478	)		525		11,746		(10,745	)		1,001
Website and acquired content		1,022		(1,022	)				1,008		(1,008	)		—
Licensed technology and other		483		(483	)				483		(483	)		—
Trademarks		3,151		(3,151	)				2,974		(2,974	)		—
Total	$	27,686		(27,148	)	$	538	$	27,238	$	(26,206	)	$	1,032

Schedule of useful lives for acquisitions

	Useful life assigned		Weighted average remaining useful life
Customer relationships		8-15 years		2 years

Schedule of finite-lived intangible assets, future amortization expense

2021	$	295
2022		243
2023		—
2024		—
2025		—