Long-Term Debt (Loan Agreements) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2013
Long-Term Debt [Abstract]
2014	$ 877
2015	608
2016	396
Total	$ 1,881

Amount of minimum loan payments maturing in the next 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