Collaborative Arrangements and Licensing Agreements, Pfizer (Details) - Pfizer [Member] - USD ($) $ in Millions	1 Months Ended
	Oct. 31, 2020	Sep. 30, 2020
Subsequent Event [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Milestone payment earned	$ 75
Next prospective milestone	$ 50
Minimum [Member]
Collaborative Arrangement and Licensing Agreement [Abstract]
Cumulative payments received		$ 255