Goodwill and intangible assets (Tables)

3 Months Ended

Oct. 31, 2020

Goodwill and Intangible Assets Disclosure [Abstract]

Schedule of Indefinite-Lived Intangible Assets

	Gross			Accumulated Amortization			Net
July 31, 2020	$	27,686		$	(27,148	)	$	538
Amortization expense		—			(75	)		(75	)
Foreign currency translation		(64	)		61			(3	)
October 31, 2020	$	27,622		$	(27,162	)	$	460

Schedule of Intangible Assets

	October 31, 2020							July 31, 2020
	Gross		Accumulated Amortization			Net		Gross		Accumulated Amortization			Net
Patents	$	11,027	$	(11,019	)	$	8	$	11,027		(11,014	)	$	13
Customer relationships		11,968		(11,516	)		452		12,003		(11,478	)		525
Website and acquired content		1,020		(1,020	)		—		1,022		(1,022	)		—
Licensed technology and other		481		(481	)		—		483		(483	)		—
Trademarks		3,126		(3,126	)		—		3,151		(3,151	)		—
Total	$	27,622	$	(27,162	)	$	460	$	27,686		(27,148	)	$	538

Schedule of Useful Lives For Acquisitions

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