Grant Revenue - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
Apr. 30, 2009	Dec. 31, 2013
Government Grant [Line Items]
Grants awarded from state of Ohio		$ 894,000
State of Ohio \| ViewRay
Government Grant [Line Items]
Grants awarded from state of Ohio	$ 2,800,000
State of Ohio \| Maximum
Government Grant [Line Items]
Grants awarded from state of Ohio	$ 5,000,000

Revenue earned during the period from non-repayable sum of money awarded to an entity to carry out a specific purpose as provided in grant agreements.

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Accounting Standards Codification

-Topic 225

-SubTopic 10

-Section S99

-Paragraph 2

-Subparagraph (SX 210.5-03.1(e))

-URI http://asc.fasb.org/extlink&oid=26872669&loc=d3e20235-122688

Name:	us-gaap_RevenueFromGrants
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration