Fair Value Measurements - Schedule of Change in Fair Value of the Contingent Consideration Liabilities (Detail) - USD ($) $ in Thousands		12 Months Ended
Feb. 02, 2022	Dec. 31, 2023	Dec. 31, 2022
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Abstract]
Balance		$ 24,026
Change in fair value		100	$ 13,485
Payment of contingent consideration		(24,126)
Balance	$ 10,541	$ 0	$ 24,026
Discount rate	7.00%		10.10%
Probability of achievement	50.00%		100.00%
Projected year of achievement	2024		2023

Discount rate

No definition available.

Name:	ntla_DiscountRate
Namespace Prefix:	ntla_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Probability of achievement

+ References

No definition available.

+ Details

Name:	ntla_ProbabilityOfAchievement
Namespace Prefix:	ntla_
Data Type:	dtr-types:percentItemType
Balance Type:	na
Period Type:	duration

- Definition

Projected year of achievement

+ References

No definition available.

+ Details

Name:	ntla_ProjectedYearOfAchievement
Namespace Prefix:	ntla_
Data Type:	xbrli:gYearItemType
Balance Type:	na
Period Type:	duration

- Definition

Fair value of contingent consideration in a business combination that is classified in shareholders' equity.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_ContingentConsiderationClassifiedAsEquityFairValueDisclosure
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- References

No definition available.

+ Details

Name:	us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisAbstract
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of settlements of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Topic 820
-SubTopic 10
-Section 50
-Paragraph 2
-Subparagraph (c)(2)
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationRecurringBasisLiabilitySettlements
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

Fair value of financial instrument classified as a liability measured using unobservable inputs that reflect the entity's own assumption about the assumptions market participants would use in pricing.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-SubTopic 10
-Topic 820
-Publisher FASB
-URI https://asc.fasb.org//1943274/2147482106/820-10-50-2

+ Details

Name:	us-gaap_FairValueMeasurementWithUnobservableInputsReconciliationsRecurringBasisLiabilityValue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant