License Agreements and Services Agreement with Ionis, Cardiometabolic Development, Commercialization and License Agreement (Details) - Ionis [Member] - Cardiometabolic Development, Commercialization and License Agreement [Member] $ in Millions	6 Months Ended
	Jun. 30, 2020 USD ($) Patient qtr
Development, Commercialization and License Agreement with Ionis [Abstract]
Royalty percentage paid on sales of lipid medicines	20.00%
First annual sales threshold | $	$ 500.0
Second annual sales threshold | $	1,000.0
Third annual sales threshold | $	2,000.0
Sales milestone payment | $	$ 50.0
Number of quarters in which equal payments are made | qtr	12
Percentage of license fees, milestone payments and royalties paid as sublicense fee to Ionis	50.00%
Lipid Drug for Rare Disease Indication [Member] | Maximum [Member]
Development, Commercialization and License Agreement with Ionis [Abstract]
Number of patients worldwide | Patient	500,000
Number of patients for Phase 3 program | Patient	1,000
Number of years of treatment	2 years
Lipid Drug for a Broad Disease Patient Population [Member] | Minimum [Member]
Development, Commercialization and License Agreement with Ionis [Abstract]
Number of patients worldwide | Patient	500,000
Number of patients for Phase 3 program | Patient	1,000
Number of years of treatment	2 years