Contingencies	3 Months Ended
	Mar. 31, 2021
Commitments and Contingencies Disclosure [Abstract]
Contingencies	ContingenciesIn February 2021, a Novavax stockholder filed a derivative complaint against members of the Company's board of directors and certain senior management in the Delaware Court of Chancery with Novavax as a nominal defendant. The complaint challenges equity awards made in April 2020 and in June 2020 on the ground that they were “spring-loaded,” that is, made at a time when certain board members or members of senior management allegedly possessed undisclosed positive material information concerning the Company. The complaint asserts claims for breach of fiduciary duty, waste, and unjust enrichment. The plaintiff seeks an award of damages to the Company, an order rescinding the 2020 awards or requiring disgorgement, and an award of attorneys’ fees incurred in connection with the litigation. The defendants intend to move to dismiss the complaint in its entirety. The financial impact of the plaintiff's claim is not estimable.