Subsequent Events - Additional Information (Detail) (Subsequent Event, Clinical development agreement, USD $) In Millions, unless otherwise specified	1 Months Ended
Jul. 31, 2012
Subsequent Event \| Clinical development agreement
Subsequent Event [Line Items]
Clinical development agreement, fund awarded by PATH	$ 2.0
Clinical development costs, percentage of funding by PATH	50.00%

Collaboration Agreement, Aggregate Research and Development Funded by Collaborator

No definition available.

Name:	nvax_CollaborationAgreementAggregateResearchAndDevelopmentFundedByCollaborator
Namespace Prefix:	nvax_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant