Collaborative Arrangements and Licensing Agreements, AstraZeneca (Details) $ in Thousands	1 Months Ended		3 Months Ended	12 Months Ended
	Dec. 31, 2021 USD ($) PerformanceObligation Component	Jul. 31, 2015 USD ($) PerformanceObligation	Dec. 31, 2021 USD ($) PerformanceObligation Component	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) PerformanceObligation Component	Dec. 31, 2020 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue				$ 587,367	$ 810,456	$ 729,264
R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue				284,009	468,061	$ 364,565
AstraZeneca [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Deferred revenue	$ 0		$ 0	$ 0	$ 0
AstraZeneca [Member] | Revenue [Member] | Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage				13.00%	31.00%	12.00%
AstraZeneca [Member] | R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue				$ 79,200	$ 254,600	$ 88,000
Eplontersen Collaboration [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable over term of collaboration				3,600,000
Upfront payment received	$ 200,000
Maximum amount of development milestone payments over term of collaboration				485,000
Maximum amount of sales milestone payments over term of collaboration				$ 2,900,000
Royalty percentage received on sales of medicine in U.S.				20.00%
Number of material components | Component	4		4		4
Number of separate performance obligations | PerformanceObligation	1		1		1
Transaction price	$ 200,000		$ 200,000		$ 200,000
Percentage of costs associated with ongoing global Phase 3 development program paid by AstraZeneca				55.00%
Next payment to be achieved				$ 50,000
Revenue					$ 200,000
Eplontersen Collaboration [Member] | Maximum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments received				260,000
Cardiovascular, Renal and Metabolic Diseases Collaboration [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Maximum amount of payments receivable over term of collaboration				5,800,000
Upfront payment received		$ 65,000
Maximum amount of license fees over term of collaboration				290,000
Maximum amount of development milestone payments over term of collaboration				1,100,000
Maximum amount of regulatory milestone payments over term of collaboration				2,900,000
Maximum amount of sales milestone payments over term of collaboration				1,500,000
Number of separate performance obligations | PerformanceObligation		1
Transaction price		$ 65,000
Next payment to be achieved				10,000
Revenue			$ 30,000
Cardiovascular, Renal and Metabolic Diseases Collaboration [Member] | Minimum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments received				280,000
Cardiovascular, Renal and Metabolic Diseases Collaboration [Member] | R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments included in transaction price for performance obligation				$ 90,000