RELATED PARTY TRANSACTIONS (Details) - Director - Consulting Agreement With Related Party Two - Restricted Stock Awards - USD ($)	1 Months Ended	12 Months Ended
Aug. 31, 2013	Dec. 31, 2013
RELATED PARTY TRANSACTIONS
Consulting agreement term	1 year
Shares of common stock granted	4,277
Vesting period of awards granted	1 year
Cash payable over term of agreement	$ 60,000
Consulting agreement expenses		$ 25,000

Represents the cash payable by the reporting entity over the term of consulting agreement.

No definition available.

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Namespace Prefix:	exas_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
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- Definition

Represents the expenses related to consulting agreement with the related party.

+ References

No definition available.

+ Details

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Data Type:	xbrli:monetaryItemType
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Period Type:	duration

- Definition

Represents the term of consulting agreement entered into by the entity with a non-employee director.

+ References

No definition available.

+ Details

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- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

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- Definition

Period which an employee's right to exercise an award is no longer contingent on satisfaction of either a service condition, market condition or a performance condition, in 'PnYnMnDTnHnMnS' format, for example, 'P1Y5M13D' represents the reported fact of one year, five months, and thirteen days.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

+ Details

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- Definition

Net number of non-option equity instruments granted to participants.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 718
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(1)(iv)(1)
-URI http://asc.fasb.org/extlink&oid=6415400&loc=d3e5070-113901

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- Details

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- Details

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