Long-Term Debt (Loan Agreements) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
2015	$ 603
2016	395
Total minimum principal payments	$ 998

Amount of minimum loan payments maturing in the second rolling twelve months following the latest balance sheet presented.

No definition available.

Name:	nvax_LoanAgreementFutureMinimumPaymentsNextRollingTwelveMonths
Namespace Prefix:	nvax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant