The potential liability for company's sale success payments.

No definition available.

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- Definition

Amount of market capitalization.

+ References

No definition available.

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- Definition

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

+ References

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

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- Definition

The increase (decrease) during the reporting period in current portion (due within one year or one business cycle) of obligations evidenced by formal promissory notes.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 28
-Subparagraph (a)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3602-108585

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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

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- Definition

The cash outflow for a borrowing supported by a written promise to pay an obligation.

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Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 230
-SubTopic 10
-Section 45
-Paragraph 15
-Subparagraph (b)
-URI http://asc.fasb.org/extlink&oid=109223946&loc=d3e3291-108585

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- Definition

Number of shares issued in lieu of cash for services contributed to the entity. Number of shares includes, but is not limited to, shares issued for services contributed by vendors and founders.

+ References

No definition available.

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Commitments and Contingencies - Notes Payable (Details) - USD ($) $ in Thousands	1 Months Ended							3 Months Ended		9 Months Ended
	Jun. 30, 2018	Jan. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Aug. 31, 2017	Mar. 31, 2017	Dec. 31, 2016	Dec. 31, 2017	Mar. 31, 2017	Sep. 30, 2017
Notes Payable
Notes paid in cash										$ 600
2016 License Agreements
Commitments and contingencies
Market Capitalization			$ 1,000,000			$ 750,000		$ 1,000,000	$ 750,000
Broad and Wageningen University \| 2016 License Agreements
Notes Payable
Promissory notes issued									$ 5,000
Broad and Wageningen University \| Cpf1 License Agreement
Notes Payable
Promissory notes issued							$ 10,000
Interest rate (as a percentage)							4.80%
Success Payments						5,000
Broad and Wageningen University \| Cpf1 License Agreement \| Success Payment Notes
Notes Payable
Promissory notes issued						$ 5,000
Broad \| 2016 License Agreements
Notes Payable
Promissory notes issued			7,500
Broad \| Cpf1 License Agreement
Notes Payable
Common stock issued				371,166	108,104
Broad \| Cpf1 License Agreement \| Success Payment Notes
Notes Payable
Promissory notes issued			7,500
Common stock issued		225,909			271,347
Success Payments			$ 7,500
Broad \| Sponsored Research Agreement
Notes Payable
Promissory notes issued	$ 12,500
Common stock issued	330,617
Broad \| Sponsored Research Agreement \| Initial Notes
Notes Payable
Promissory notes issued	$ 12,500
Interest rate (as a percentage)	4.80%
Wageningen University \| Cpf1 License Agreement
Notes Payable
Notes paid in cash					$ 200
Wageningen University \| Cpf1 License Agreement \| Success Payment Notes
Notes Payable
Notes paid in cash					$ 400
The General Hospital (MGH) \| 2016 License Agreements
Notes Payable
Success Payments								$ 2,000