Joint Venture - Summary of Financial Information of Joint Ventures (Balance Sheet Data) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Mar. 31, 2021	Jun. 30, 2020	Mar. 31, 2020	Jun. 30, 2019	Jun. 30, 2018
Schedule Of Equity Method Investments [Line Items]
Current assets	$ 352,773		$ 357,486
Total assets	480,098		490,927
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities	192,359		182,271
Stockholder's equity	68,840		63,635		$ 49,871	$ 48,632
Total liabilities and stockholders’ equity	$ 480,098		$ 490,927
CNNC Accuray (Tianjin) Medical Technology Co. Ltd.
Schedule Of Equity Method Investments [Line Items]
Current assets		$ 24,703		$ 16,776
Non current assets		23,089		16,125
Total assets		47,792		32,901
LIABILITIES AND STOCKHOLDERS’ EQUITY
Current liabilities		16,854		9,064
Non current liabilities		1,467		1,412
Stockholder's equity		29,471		22,425
Total liabilities and stockholders’ equity		$ 47,792		$ 32,901