Collaborative Arrangements and Licensing Agreements, Alnylam Pharmaceuticals, Inc. (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2020	Dec. 31, 2020	Dec. 31, 2019	Dec. 31, 2018
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue		$ 729,264	$ 1,122,599	$ 599,674
R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue		364,565	770,149	$ 344,752
Alnylam [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Award from arbitration panel	$ 41,200
Revenue	41,200
Deferred revenue	$ 0	$ 0	$ 0
Alnylam [Member] | Revenue [Member] | Strategic Partner [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Concentration percentage		7.00%	2.00%	0.00%
Alnylam [Member] | R&D Revenue [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Revenue		$ 47,900	$ 24,100	$ 2,000