Organization and Significant Accounting Policies, Revenue Recognition (Details) $ in Thousands	12 Months Ended
	Dec. 31, 2022 USD ($)	Dec. 31, 2021 USD ($) PerformanceObligation Component	Dec. 31, 2020 USD ($)
Revenue Recognition [Abstract]
Revenue	$ 587,367	$ 810,456	$ 729,264
Eplontersen Collaboration with AstraZeneca [Member]
Revenue Recognition [Abstract]
Revenue		$ 200,000
Number of material components | Component		4
Number of separate performance obligations | PerformanceObligation		1
Transaction price		$ 200,000
Percentage of costs associated with ongoing global Phase 3 development program paid by AstraZeneca	55.00%