Joint Venture - Summary of Financial Information of Joint Ventures (Balance Sheet Data) (Details) - USD ($) $ in Thousands	Sep. 30, 2021	Jun. 30, 2021	Sep. 30, 2020	Jun. 30, 2020
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 350,518	$ 352,773
Total assets	475,776	480,098
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities	188,317	192,359
Stockholder's equity	45,765	68,840	$ 67,440	$ 63,635
Total liabilities and stockholders' equity	$ 475,776	480,098
CNNC Accuray (Tianjin) Medical Technology Co. Ltd.
Schedule Of Equity Method Investments [Line Items]
Current assets		31,759		23,314
Non current assets		22,763		17,287
Total assets		54,522		40,601
LIABILITIES AND STOCKHOLDERS' EQUITY
Current liabilities		24,445		15,934
Non current liabilities		1,300		1,397
Stockholder's equity		28,777		23,270
Total liabilities and stockholders' equity		$ 54,522		$ 40,601