Identification of the lender and information about a contractual promise to repay a short-term or long-term obligation, which includes borrowings under lines of credit, notes payable, commercial paper, bonds payable, debentures, and other contractual obligations for payment. This may include rationale for entering into the arrangement, significant terms of the arrangement, which may include amount, repayment terms, priority, collateral required, debt covenants, borrowing capacity, call features, participation rights, conversion provisions, sinking-fund requirements, voting rights, basis for conversion if convertible and remarketing provisions. The description may be provided for individual debt instruments, rational groupings of debt instruments, or by debt in total.

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.22)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 505
-SubTopic 10
-Section 50
-Paragraph 3
-URI http://asc.fasb.org/extlink&oid=6928386&loc=d3e21475-112644

Reference 3: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 942
-SubTopic 470
-Section 50
-Paragraph 3
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=6479336&loc=d3e64711-112823

Reference 4: http://www.xbrl.org/2003/role/presentationRef
-Publisher SEC
-Name Regulation S-X (SX)
-Number 210
-Section 02
-Paragraph 19, 20, 22
-Article 5

+ Details

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Balance Type:	na
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- Definition

Contractual interest rate for funds borrowed, under the debt agreement.

+ References

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Period Type:	instant

- Definition

Date when the debt instrument is scheduled to be fully repaid, in CCYY-MM-DD format.

+ References

+ Details

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Namespace Prefix:	us-gaap_
Data Type:	xbrli:dateItemType
Balance Type:	na
Period Type:	duration

- Definition

The cash outflow during the period from the repayment of aggregate short-term and long-term debt. Excludes payment of capital lease obligations.

+ References

No definition available.

+ Details

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Balance Type:	credit
Period Type:	duration

- Definition

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.

+ References

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

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- Definition

Debt Instrument Maximum Borrowing Capacity

+ References

No definition available.

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- Definition

Government Grant [Line Items]

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Grant Revenue - Additional Information (Detail) - USD ($)		1 Months Ended	12 Months Ended
	Jul. 31, 2010	Apr. 30, 2009	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2008
Government Grant [Line Items]
Maximum borrowing capacity under the agreement						$ 800,000
Stated interest rate						6.00%
Debt maturity date			Dec. 31, 2009
Debt description			Under the terms of the loan agreement, the lender may forgive $240 thousand if the Company meets certain permanent job creation requirements within the State of Ohio. In July 2010, $560 thousand of principal and accrued interest through the loan maturity date were repaid. In September 2015, the remaining $240 thousand was forgiven and was recognized as grant revenue during the year ended December 31, 2015.
Repayment of debt	$ 560,000
Grants awarded from state of Ohio			$ 240,000	$ 0	$ 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