Master Services Agreement with Cadila (Details) (USD $) In Millions, unless otherwise specified	9 Months Ended	42 Months Ended
Sep. 30, 2012	Sep. 30, 2012
Master Services Agreement with Cadila [Abstract]
Minimum contract services to be provided		$ 7.5
Shortfall amount fully payable	2.0
Payable portion of the shortfall amount exceeding two million	50.00%
Purchases		$ 0.4

Master Services Agreement Amount Of Services To Be Provided Minimum

No definition available.

Name:	nvax_MasterServicesAgreementAmountOfServicesToBeProvidedMinimum
Namespace Prefix:	nvax_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	duration