The remaining amount of success payments that may become due as part of a licensing agreement.

No definition available.

Name:	beam_AdditionalSuccessPaymentAmountDue
Namespace Prefix:	beam_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Number of shares issued to satisfy success payment obligation.

+ References

No definition available.

+ Details

Name:	beam_StockIssuedDuringPeriodSharesSuccessPaymentLiability
Namespace Prefix:	beam_
Data Type:	xbrli:sharesItemType
Balance Type:	na
Period Type:	duration

- Definition

The amount of success payment due as part of a license agreement.

+ References

No definition available.

+ Details

Name:	beam_SuccessPaymentAmountDue
Namespace Prefix:	beam_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

The amount of success payments payable upon achievement of specified stock value targets.

+ References

No definition available.

+ Details

Name:	beam_SuccessPayments
Namespace Prefix:	beam_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration

- Definition

The valuation multiple applied to the initial weighted average of the specified class of stock, used to determine success payment targets.

+ References

No definition available.

+ Details

Name:	beam_SuccessPaymentsValuationMultiples
Namespace Prefix:	beam_
Data Type:	xbrli:pureItemType
Balance Type:	na
Period Type:	duration

- Definition

Description of nature and purpose of collaborative arrangements.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (a)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

+ Details

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

- 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

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 808
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 1
-Subparagraph (d)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147479402/808-10-50-1

+ Details

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

- Details

Name:	us-gaap_TypeOfArrangementAxis=beam_HarvardLicenseAgreementMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementEquityComponentsAxis=us-gaap_CommonStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MinimumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_StatementClassOfStockAxis=us-gaap_SeriesAPreferredStockMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_RangeAxis=srt_MaximumMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	srt_ProductOrServiceAxis=beam_SuccessPaymentsMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

License and Other Agreements - Harvard License Agreement - Additional Information (Details) - Harvard		3 Months Ended
	Jun. 10, 2021 shares	Mar. 31, 2026 USD ($)	May 31, 2021 USD ($)
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payment amount due		$ 0	$ 15,000,000
Common Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Issuance of common stock for success payment liability, Shares \| shares	174,825
Minimum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success payments		$ 5,000,000
Minimum \| Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		5
Maximum
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Additional success payment amount due		$ 90,000,000
Success payments		$ 105,000,000
Maximum \| Series A Preferred Stock
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Success Payments, valuation multiples		40
Success Payments
Collaborative Arrangements And Noncollaborative Arrangement Transactions [Line Items]
Agreement description		The Company is required to make success payments to Harvard during a period of time, or the Harvard Success Payment Period, which has been determined to be the later of (1) the ninth anniversary of the Harvard License Agreement or (2) the earlier of (a) the twelfth anniversary of the Harvard License Agreement and (b) the third anniversary of the first date on which a licensed product receives regulatory approval in the United States. During the Harvard Success Payment Period, the Company will perform a calculation of any amounts owed to Harvard on each rolling 90-day period, commencing one year after the IPO.