Background and Organization - Additional Information (Detail) $ / shares in Units, $ in Thousands				3 Months Ended		9 Months Ended
	Sep. 09, 2016 $ / shares shares	Aug. 17, 2015 USD ($) $ / shares shares	Jul. 08, 2015 $ / shares shares	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	Sep. 30, 2016 USD ($) $ / shares shares	Sep. 30, 2015 USD ($)	Aug. 22, 2016 shares	Dec. 31, 2015 $ / shares shares	Jul. 21, 2015 $ / shares shares	Jul. 20, 2015 $ / shares shares	Jul. 07, 2015 $ / shares shares
Background And Organization [Line Items]
Description of the stock split arrangement						On July 8, 2015, ViewRay, Inc. (f/k/a Mirax Corp.), or ViewRay, we, us, our, or the Company, completed a 1.185763-for-1 forward stock split of its common stock in the form of a dividend with the result that 4,343,339 shares of common stock, par value $0.001 per share, outstanding immediately prior to the stock split became 5,150,176 shares of common stock, par value $0.001 per share, outstanding immediately thereafter.
Stock split conversion ratio			1.185763
Common stock, shares outstanding			5,150,176	43,354,677		43,354,677			38,204,960			4,343,339
Common stock, par value | $ / shares			$ 0.001	$ 0.01		$ 0.01			$ 0.01	$ 0.01	$ 0.001	$ 0.001
Common stock, shares authorized				300,000,000		300,000,000			300,000,000	300,000,000	75,000,000
Net loss from operations | $				$ (14,146)	$ (10,260)	$ (39,629)	$ (30,889)
Net cash used from operations | $						$ (28,070)	$ (31,305)
2015 Private Placement
Background And Organization [Line Items]
Private placement, common shares		5,884,504
Purchase price of share common stock, per share | $ / shares		$ 5.00
Private placement, value | $		$ 26,300
2016 Placement Warrants
Background And Organization [Line Items]
Sale of common stock shares	4,602,506
Common stock, shares issued, price per share | $ / shares	$ 2.95
Warrants issued	1,380,745			1,380,745		1,380,745		1,380,745
Warrants issued price per share | $ / shares	$ 0.125
Proceeds from sale of private placement, net of offering cost | $						$ 13,200
Blank Check Preferred Stock
Background And Organization [Line Items]
Preferred stock, shares authorized										10,000,000
Preferred stock, par value | $ / shares										$ 0.01