Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-in Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning balance at Aug. 31, 2020	$ 733,757	$ 1,333	$ (64,688)	$ 821,446		$ (24,334)
Beginning balance, shares at Aug. 31, 2020		133,269,301	2,555,556
Net income (loss)	(4,651)					(4,651)
Repurchase of common stock	(57)		$ (57)
Repurchase of common stock, shares			1,475
Share-based compensation expense	2,333			2,333
Vesting of restricted stock awards		$ 1		(1)
Vesting of restricted stock awards, shares		142,193
Ending balance at Nov. 30, 2020	731,382	$ 1,334	$ (64,745)	823,778		(28,985)
Ending balance, shares at Nov. 30, 2020		133,411,494	2,557,031
Beginning balance at Aug. 31, 2020	733,757	$ 1,333	$ (64,688)	821,446		(24,334)
Beginning balance, shares at Aug. 31, 2020		133,269,301	2,555,556
Net income (loss)	(11,372)
Ending balance at May. 31, 2021	734,601	$ 1,342	$ (64,745)	833,631	$ 79	(35,706)
Ending balance, shares at May. 31, 2021		134,217,410	2,557,031
Beginning balance at Nov. 30, 2020	731,382	$ 1,334	$ (64,745)	823,778		(28,985)
Beginning balance, shares at Nov. 30, 2020		133,411,494	2,557,031
Net income (loss)	(6,364)					(6,364)
Proceeds from follow-on offering, net of issuance costs	3,453	$ 1		3,452
Proceeds from follow-on offering, net of issuance costs, shares		90,000
Share-based compensation expense	2,478			2,478
Issuance of common stock upon exercise of stock options	993			993
Issuance of common stock upon exercise of stock options, shares		36,809
Vesting of restricted stock awards		$ 6		(6)
Vesting of restricted stock awards, shares		543,170
Unrealized loss on available-for-sale securities	(6)				(6)
Ending balance at Feb. 28, 2021	731,936	$ 1,341	$ (64,745)	830,695	(6)	(35,349)
Ending balance, shares at Feb. 28, 2021		134,081,473	2,557,031
Net income (loss)	(357)					(357)
Share-based compensation expense	1,974			1,974
Issuance of common stock upon exercise of stock options	963			963
Issuance of common stock upon exercise of stock options, shares		35,674
Vesting of restricted stock awards		$ 1		(1)
Vesting of restricted stock awards, shares		100,263
Unrealized gain on available-for-sale securities	85				85
Ending balance at May. 31, 2021	734,601	$ 1,342	$ (64,745)	833,631	79	(35,706)
Ending balance, shares at May. 31, 2021		134,217,410	2,557,031
Beginning balance at Aug. 31, 2021	730,738	$ 1,346	$ (67,764)	838,357	64	(41,265)
Beginning balance, shares at Aug. 31, 2021		134,625,379	2,625,062
Net income (loss)	692					692
Repurchase of common stock	(141)		$ (141)
Repurchase of common stock, shares			3,301
Share-based compensation expense	2,481			2,481
Issuance of common stock upon exercise of stock options	132			132
Issuance of common stock upon exercise of stock options, shares		4,897
Vesting of restricted stock awards		$ 1		(1)
Vesting of restricted stock awards, shares		60,148
Unrealized loss on available-for-sale securities	(13)				(13)
Ending balance at Nov. 30, 2021	733,889	$ 1,347	$ (67,905)	840,969	51	(40,573)
Ending balance, shares at Nov. 30, 2021		134,690,424	2,628,363
Beginning balance at Aug. 31, 2021	730,738	$ 1,346	$ (67,764)	838,357	64	(41,265)
Beginning balance, shares at Aug. 31, 2021		134,625,379	2,625,062
Net income (loss)	(5,951)
Ending balance at May. 31, 2022	733,109	$ 1,352	$ (68,110)	846,914	169	(47,216)
Ending balance, shares at May. 31, 2022		135,183,927	2,636,816
Beginning balance at Nov. 30, 2021	733,889	$ 1,347	$ (67,905)	840,969	51	(40,573)
Beginning balance, shares at Nov. 30, 2021		134,690,424	2,628,363
Net income (loss)	(879)					(879)
Repurchase of common stock	(95)		$ (95)
Repurchase of common stock, shares			3,099
Share-based compensation expense	3,380			3,380
Vesting of restricted stock awards		$ 4		(4)
Vesting of restricted stock awards, shares		434,689
Unrealized loss on available-for-sale securities	(51)				(51)
Ending balance at Feb. 28, 2022	736,244	$ 1,351	$ (68,000)	844,345		(41,452)
Ending balance, shares at Feb. 28, 2022		135,125,113	2,631,462
Net income (loss)	(5,764)					(5,764)
Repurchase of common stock	(110)		$ (110)
Repurchase of common stock, shares			5,354
Share-based compensation expense	2,569			2,569
Vesting of restricted stock awards	1	$ 1
Vesting of restricted stock awards, shares		58,814
Unrealized gain on available-for-sale securities	169				169
Ending balance at May. 31, 2022	$ 733,109	$ 1,352	$ (68,110)	$ 846,914	$ 169	$ (47,216)
Ending balance, shares at May. 31, 2022		135,183,927	2,636,816