Consolidated Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit
Beginning Balance, Amount at Sep. 30, 2020	$ 461,779	$ 195	$ 965,410	$ 18	$ (503,844)
Beginning Balance, Shares at Sep. 30, 2020		102,376,000
Stock-based compensation	23,502		23,502
Exercise of stock options, Amount	7,734		7,734
Exercise of stock options, Shares		820,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		824,000
Foreign currency translation adjustments	84			84
Net income (loss)	(47,550)				(47,550)
Ending Balance, Amount at Mar. 31, 2021	445,549	$ 196	996,645	102	(551,394)
Ending Balance, Shares at Mar. 31, 2021		104,020,000
Beginning Balance, Amount at Dec. 31, 2020	454,472	$ 195	978,655	198	(524,576)
Beginning Balance, Shares at Dec. 31, 2020		103,194,000
Stock-based compensation	15,359		15,359
Exercise of stock options, Amount	2,632		2,632
Exercise of stock options, Shares		282,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		544,000
Foreign currency translation adjustments	(96)			(96)
Net income (loss)	(26,818)				(26,818)
Ending Balance, Amount at Mar. 31, 2021	445,549	$ 196	996,645	102	(551,394)
Ending Balance, Shares at Mar. 31, 2021		104,020,000
Beginning Balance, Amount at Sep. 30, 2021	408,822	$ 197	1,053,386	(69)	(644,692)
Beginning Balance, Shares at Sep. 30, 2021		104,327,000
Stock-based compensation	58,306		58,306
Exercise of stock options, Amount	$ 3,682		3,682
Exercise of stock options, Shares	444,764	444,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		931,000
Foreign currency translation adjustments	$ (38)			(38)
Net income (loss)	(18,506)				(18,506)
Ending Balance, Amount at Mar. 31, 2022	452,266	$ 198	1,115,373	(107)	(663,198)
Ending Balance, Shares at Mar. 31, 2022		105,702,000
Beginning Balance, Amount at Dec. 31, 2021	372,560	$ 197	1,080,035	(108)	(707,564)
Beginning Balance, Shares at Dec. 31, 2021		104,798,000
Stock-based compensation	33,802		33,802
Exercise of stock options, Amount	1,537		1,537
Exercise of stock options, Shares		237,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		667,000
Foreign currency translation adjustments	1			1
Net income (loss)	44,366				44,366
Ending Balance, Amount at Mar. 31, 2022	$ 452,266	$ 198	$ 1,115,373	$ (107)	$ (663,198)
Ending Balance, Shares at Mar. 31, 2022		105,702,000