Joint Venture - Additional Information (Details) - USD ($)	12 Months Ended
	Jun. 30, 2021	Jun. 30, 2020	Jun. 30, 2019	Jan. 31, 2019
Schedule Of Equity Method Investments [Line Items]
Gain on contribution to joint venture		$ 12,964,000
Accumulated deficit	$ (488,024,000)	(481,713,000)
Goodwill	57,960,000	57,717,000	$ 57,770,000
Impairment of goodwill	$ 0	0	$ 0
Accuray Asia
Schedule Of Equity Method Investments [Line Items]
Percentage of ownership interest in joint venture	49.00%			49.00%
Gain on contribution to joint venture		13,000,000.0
Percentage of ownership interest in joint venture	49.00%
Accumulated deficit	$ 900,000
Deferred of intra-entity profit margin	2,100,000	$ 1,800,000
Previously deferred intra-entity margin from system sales	1,800,000
Deferral of intra entity margin from system sales	2,100,000
Equity method investment	15,900,000
Proportional share of underlying equity in net assets	13,700,000
Proportional share of underlying equity in net assets, difference amount	2,200,000
Elimination of equity method investment intra-entity profit on sales	2,100,000
Goodwill	4,400,000
Impairment of foreign currency exchange	100,000
Impairment of goodwill	$ 0