Collaborative Arrangement, Commercial Milestones Acquired By Collaborator, Percent

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- Definition

Collaborative Arrangement, Consideration Received

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- Definition

Collaborative Arrangement, Fixed Payment, Number Of Quarterly Payments

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- Definition

Collaborative Arrangement, Fixed Payment, Term

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- Definition

Collaborative Arrangement, Maximum Funding

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- Definition

Collaborative Arrangement, Milestone Payable

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- Definition

Collaborative Arrangement, Royalties Acquired By Collaborator, Percent

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No definition available.

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- Definition

Collaborative Arrangement, Royalties Payable, Percent

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- Definition

Collaborative Arrangement, Royalties Payable, Term

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- Definition

Expected Royalty Interest Payments

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- Definition

Liability Related To The Sale Of Future Royalties [Line Items]

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No definition available.

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- Definition

Number Of Cardiometabolic Programs

+ References

No definition available.

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- Definition

Royalty And Development Funding Liability, Current

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No definition available.

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- Definition

Royalty And Development Funding Liability, Fair Value

+ References

No definition available.

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- Definition

Royalty And Development Funding Liability, Noncurrent

+ References

No definition available.

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- Definition

Royalty Liability, Closing Costs

+ References

No definition available.

+ Details

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- Definition

Royalty Liability, Fair Value

+ References

No definition available.

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- Definition

Royalty Liability, Interest Rate

+ References

No definition available.

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- Definition

Royalty Liability, Noncurrent

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No definition available.

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- Definition

Effective interest rate for the funds borrowed under the debt agreement considering interest compounding and original issue discount or premium.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
-SubTopic 210
-Name Accounting Standards Codification
-Section S45
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147477657/942-210-S45-1

Reference 2: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478478/942-210-S50-1

Reference 3: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 942
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147478546/942-210-S99-1

Reference 4: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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-Name Accounting Standards Codification
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147480566/210-10-S99-1

Reference 5: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 210
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-Name Accounting Standards Codification
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-URI https://asc.fasb.org/1943274/2147480657/210-10-S50-9

Reference 6: http://www.xbrl.org/2003/role/exampleRef
-Topic 835
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Reference 7: http://www.xbrl.org/2003/role/disclosureRef
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Reference 8: http://www.xbrl.org/2003/role/disclosureRef
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Reference 9: http://www.xbrl.org/2003/role/disclosureRef
-Topic 470
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-Publisher FASB
-URI https://asc.fasb.org/1943274/2147481139/470-20-50-6

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LIABILITIES RELATED TO THE SALE OF FUTURE ROYALTIES AND DEVELOPMENT FUNDING - Additional Information (Detail) $ in Thousands			1 Months Ended
	Jun. 30, 2026 USD ($)	Mar. 31, 2025	Jun. 30, 2026 USD ($)	Sep. 30, 2025 USD ($)	Mar. 31, 2025 USD ($) payment	Sep. 30, 2023 USD ($) payment	Aug. 31, 2020 USD ($) program	Apr. 30, 2020 USD ($)	Jan. 01, 2030	Dec. 31, 2025 USD ($)
Liability Related To The Sale Of Future Royalties [Line Items]
Number of cardiometabolic programs \| program							2
Liabilities related to the sale of future royalties and development funding	$ 258,570		$ 258,570							$ 220,068
Liabilities related to the sale of future royalties and development funding, net of current portion	$ 1,461,510		$ 1,461,510							$ 1,470,341
Vutrisiran
Liability Related To The Sale Of Future Royalties [Line Items]
Effective interest rate	51.00%		51.00%							46.00%
Liabilities related to the sale of future royalties and development funding	$ 89,900		$ 89,900							$ 94,500
Liabilities related to the sale of future royalties and development funding, net of current portion	$ 91,200		$ 91,200							$ 99,700
Zilebesrian
Liability Related To The Sale Of Future Royalties [Line Items]
Effective interest rate	31.00%		31.00%							32.00%
Liabilities related to the sale of future royalties and development funding	$ 2,100		$ 2,100							$ 6,800
Liabilities related to the sale of future royalties and development funding, net of current portion	20,200		20,200							10,300
Blackstone Life Sciences \| Vutrisiran and ALN-AGT \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Maximum funding							$ 150,000
Blackstone Life Sciences \| HELIOS-B Phase 3 Clinical Trial \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Maximum funding			70,000
Blackstone Life Sciences \| ALN-AGT Phase 2 Clinical Trial
Liability Related To The Sale Of Future Royalties [Line Items]
Development milestone payable						$ 84,500
Blackstone Life Sciences \| ALN-AGT Phase 2 Clinical Trial \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Maximum funding			26,000
Number of quarterly payments \| payment						16
Fixed payment, term (in years)						4 years
Blackstone Life Sciences \| ALN-AGT Phase 3 Clinical Trial \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Maximum funding	18,000		36,000	$ 36,000
Development milestone payable						$ 243,000
Number of quarterly payments \| payment						16
Fixed payment, term (in years)						4 years
Blackstone Life Sciences \| Vutrisiran
Liability Related To The Sale Of Future Royalties [Line Items]
Development milestone payable					$ 175,000
Blackstone Life Sciences \| Vutrisiran \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Royalties payable, percent							1.00%
Royalties payable, term (in years)							10 years
Number of quarterly payments \| payment					8
Fixed payment, term (in years)		2 years
Blackstone Life Sciences \| Development Milestone
Liability Related To The Sale Of Future Royalties [Line Items]
Development milestone payable							$ 175,000
Vutrisiran
Liability Related To The Sale Of Future Royalties [Line Items]
Royalty and development funding liability, fair value	555,300		555,300							541,300
Zilebesrian
Liability Related To The Sale Of Future Royalties [Line Items]
Royalty and development funding liability, fair value	119,600		119,600							116,200
Blackstone Group Inc.
Liability Related To The Sale Of Future Royalties [Line Items]
Liabilities related to the sale of future royalties and development funding	166,600		166,600							118,800
Liabilities related to the sale of future royalties and development funding, net of current portion	$ 1,350,000		$ 1,350,000							$ 1,360,000
Blackstone Group Inc. \| Net revenues from collaborations
Liability Related To The Sale Of Future Royalties [Line Items]
Collaborative arrangement, royalties and commercial milestones acquired by collaborator, percent								50.00%
Commercial milestones acquired by collaborator, percent								75.00%
Expected royalty interest payments								$ 1,000,000
Consideration received								$ 1,000,000
Interest rate	14.00%		14.00%							10.00%
Liabilities related to the sale of future royalties and development funding, net of current portion	$ 1,516,710		$ 1,516,710							$ 1,479,209
Closing costs	7,900		7,900							8,300
Fair value of liability	$ 1,960,000		$ 1,960,000							$ 1,610,000
Blackstone Group Inc. \| Net revenues from collaborations \| Forecast
Liability Related To The Sale Of Future Royalties [Line Items]
Collaborative arrangement, royalties and commercial milestones acquired by collaborator, percent									55.00%