Long-Term Debt (Loan Agreements) (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012
Long-Term Debt [Abstract]
2013	$ 357
2014	357
2015	157
2016	39
Total	$ 910

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