Consolidated Statements of Stockholders' Equity (unaudited) - USD ($) $ in Thousands	Total	Common Stock	Additional Paid-In Capital	Accumulated Other Comprehensive Income (Loss)	Accumulated Deficit	Non-controlling Interest
Beginning Balance, Amount at Sep. 30, 2019	$ 244,036	$ 187	$ 664,086	$ (391)	$ (419,291)	$ (555)
Beginning Balance, Shares at Sep. 30, 2019		95,506,000
Stock-based compensation	17,464		17,464
Exercise of stock options, Amount	4,332	$ 1	4,331
Exercise of stock options, Shares		686,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		956,000
Common stock - issued for cash, Amount	250,479	$ 5	250,474
Common stock - issued for cash, Shares		4,600,000
Foreign currency translation adjustments	(238)			(238)
Net income (loss)	(22,509)				(22,509)
Ending Balance, Amount at Mar. 31, 2020	493,564	$ 194	936,354	(629)	(441,800)	(555)
Ending Balance, Shares at Mar. 31, 2020		101,748,000
Beginning Balance, Amount at Dec. 31, 2019	499,529	$ 193	922,051	(196)	(421,964)	(555)
Beginning Balance, Shares at Dec. 31, 2019		101,112,000
Stock-based compensation	12,972		12,972
Exercise of stock options, Amount	1,330		1,330
Exercise of stock options, Shares		214,000
Common stock - restricted stock units vesting, Amount		$ 1	(1)
Common stock - restricted stock units vesting, Shares		422,000
Common stock - issued for cash, Amount	2		2
Foreign currency translation adjustments	(433)			(433)
Net income (loss)	(19,836)				(19,836)
Ending Balance, Amount at Mar. 31, 2020	493,564	$ 194	936,354	(629)	(441,800)	$ (555)
Ending Balance, Shares at Mar. 31, 2020		101,748,000
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	819,668	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