Joint Venture - Additional Information (Details) - USD ($)	3 Months Ended			9 Months Ended		12 Months Ended
	Mar. 31, 2022	Dec. 31, 2021	Mar. 31, 2021	Mar. 31, 2022	Mar. 31, 2021	Jun. 30, 2021	Jun. 30, 2020	Jan. 31, 2019
Schedule Of Equity Method Investments [Line Items]
Accumulated deficit	$ 489,070,000			$ 489,070,000		$ 488,024,000
Investee's currency translation adjustment				40,000		243,000
Proportional share of underlying equity in net assets, difference amount	1,000.0			1,000.0
Goodwill	$ 58,000,000			$ 58,000,000		57,960,000	$ 57,717,000
Impairment of goodwill		$ 0
Accuray Asia
Schedule Of Equity Method Investments [Line Items]
Percentage of ownership interest in joint venture	49.00%			49.00%				49.00%
Deferred of intra-entity profit margin	$ 5,700,000			$ 5,700,000		$ 2,100,000
Previously deferred intra-entity margin from system sales	300,000		$ 400,000	1,500,000	$ 1,900,000
Deferral of intra entity margin from system sales	2,900,000		$ 800,000	5,000,000.0	$ 1,700,000
Accumulated deficit	1,500,000			1,500,000
Equity method investment	14,300,000			14,300,000
Proportional share of underlying equity in net assets	15,200,000			15,200,000
Investee's currency translation adjustment				1,100,000
Elimination of equity method investment intra-entity profit on sales	5,700,000
Goodwill	4,700,000			$ 4,700,000
Impairment of goodwill	$ 0