Collaborative Arrangements and Licensing Agreements, Roche (Details) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2024 USD ($) Agreement	Sep. 30, 2023 USD ($)	Sep. 30, 2024 USD ($) Agreement	Sep. 30, 2023 USD ($)	Dec. 31, 2023 USD ($)
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue	$ 133,814	$ 144,207	$ 478,562	$ 463,142
Roche [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of collaboration agreements | Agreement	3		3
Revenue	$ 11,084	$ 8,858	$ 33,679	$ 16,979
Deferred contract revenue	$ 4,500		$ 4,500		$ 36,700
Roche [Member] | Revenue [Member] | Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage	8.00%	6.00%	7.00%	4.00%
Roche [Member] | Minimum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments received	$ 345,000		$ 345,000
HD [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of collaboration agreements | Agreement	1		1
IONIS-FB-L for Complement-Mediated Diseases [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of collaboration agreements | Agreement	1		1
Maximum amount of payments receivable over term of collaboration	$ 430,000		$ 430,000
Maximum amount of license fees over term of collaboration	35,000		35,000
Maximum amount of development milestone payments over term of collaboration	25,000		25,000
Maximum amount of regulatory milestone payments over term of collaboration	90,000		90,000
Maximum amount of sales milestone payments over term of collaboration	280,000		280,000
Next payment to be achieved	23,500		$ 23,500
Revenue	$ 8,500
RNA-targeted Programs for AD and HD [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Number of collaboration agreements | Agreement	1		1