License agreement with Wyeth Holding Corporation (Details) (License agreement, Wyeth, USD $) In Millions, unless otherwise specified	9 Months Ended	93 Months Ended
Sep. 30, 2014	Sep. 30, 2014
License agreement \| Wyeth
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Notice period required for termination of license agreement	90 days
Aggregate amount of payments made under license agreement		$ 6.4
Expected milestone payment associated with the first Phase 3 clinical trial	$ 3.0	$ 3.0

Represents the aggregate amount of payments made under the license agreement as of the balance sheet date.

No definition available.

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