Organization (Details)	Mar. 31, 2013
Schedule of Equity Method Investments [Line Items]
Ownership percent of joint venture	20.00%
Cadila [Member]
Schedule of Equity Method Investments [Line Items]
Ownership percent of joint venture	80.00%

The percentage of the joint venture owned by others.

No definition available.

Name:	nvax_JointVenturePercentageOwnedByOthers
Namespace Prefix:	nvax_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant