Revenues - Revenues (Details) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2025	Jun. 30, 2024	Jun. 30, 2025	Jun. 30, 2024
Revenue:
Revenue	$ 452,049	$ 225,250	$ 583,660	$ 344,748
TRYNGOLZA Sales, Net [Member]
Revenue:
Revenue	19,273	0	25,561	0
Product Sales, Net [Member]
Revenue:
Revenue	19,273	0	25,561	0
SPINRAZA Royalties [Member]
Revenue:
Revenue	54,337	56,743	102,347	95,198
WAINUA Royalties [Member]
Revenue:
Revenue	10,415	3,781	19,787	4,907
Other Royalties [Member]
Revenue:
Revenue	5,200	3,320	11,983	13,124
Royalty [Member]
Revenue:
Revenue	69,952	63,844	134,117	113,229
TEGSEDI and WAYLIVRA Revenue, Net [Member]
Revenue:
Revenue	13,531	8,192	19,246	16,820
Other Revenue [Member]
Revenue:
Revenue	0	0	0	1,580
Other Commercial Revenue [Member]
Revenue:
Revenue	13,531	8,192	19,246	18,400
Commercial Revenue [Member]
Revenue:
Revenue	102,756	72,036	178,924	131,629
Collaborative Agreement Revenue [Member]
Revenue:
Revenue	336,921	141,524	381,951	190,870
WAINUA Joint Development Revenue [Member]
Revenue:
Revenue	12,372	11,690	22,785	22,249
Research and Development Revenue [Member]
Revenue:
Revenue	$ 349,293	$ 153,214	$ 404,736	$ 213,119