Long-Term Obligations and Commitments, Royalty Revenue Monetization (Details) - USD ($) $ in Thousands	1 Months Ended	12 Months Ended
	Jan. 31, 2023	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Royalty Revenue Monetization [Abstract]
Upfront payment received	$ 500,000
Maximum amount of payments receivable for additional milestones	625,000
Transaction costs		$ 0	$ 10,434	$ 29
Proceeds from sale of future royalties		0	500,000	0
Issuance costs related to sale of future royalties		0	(10,434)	(29)
Royalty payments to Royalty Pharma		(44,981)	(44,628)	0
Interest expense related to sale of future royalties		72,846	68,238	$ 0
Net liability related to sale of future royalties		542,212	513,736
SPINRAZA [Member]
Royalty Revenue Monetization [Abstract]
Maximum amount of annual sales on which royalty payments are paid	$ 1,500,000	$ 1,500,000
SPINRAZA [Member] | Minimum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	25.00%	25.00%
Maximum royalty payments made before royalty interest reverts back	$ 475,000	$ 475,000
SPINRAZA [Member] | Maximum [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	45.00%	45.00%
Maximum royalty payments made before royalty interest reverts back	$ 550,000	$ 550,000
Pelacarsen [Member]
Royalty Revenue Monetization [Abstract]
Percentage of royalty payments paid on annual sales of medicine	25.00%
Royalty Purchase Agreement [Member]
Royalty Revenue Monetization [Abstract]
Transaction costs		$ 10,400	$ 10,434
Effective interest rate		13.50%	13.50%
Proceeds from sale of future royalties	$ 500,000
Issuance costs related to sale of future royalties		$ (10,400)	$ (10,434)
Royalty payments to Royalty Pharma		(44,981)	(44,628)
Interest expense related to sale of future royalties		72,846	68,238
Amortization of issuance costs related to sale of future royalties		611	560
Net liability related to sale of future royalties		$ 542,212	$ 513,736