Grant agreement

No definition available.

Name:	nvax_GrantAgreement
Namespace Prefix:	nvax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

Amount of the funding increased to allow the recovery of additional costs under the contract relating to the settlement of indirect rates.

+ References

No definition available.

+ Details

Name:	nvax_IncreaseInFundingForRecoveryOfAdditionalCostsUnderContract
Namespace Prefix:	nvax_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The percentage of the joint venture owned by others.

+ References

No definition available.

+ Details

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

- Definition

Line items represent financial concepts included in a table. These concepts are used to disclose reportable information associated with domain members defined in one or many axes to the table.

+ References

No definition available.

+ Details

Name:	us-gaap_CollaborativeArrangementsAndNoncollaborativeArrangementTransactionsLineItems
Namespace Prefix:	us-gaap_
Data Type:	xbrli:stringItemType
Balance Type:	na
Period Type:	duration

- Definition

Amount of revenue earned from products sold or services provided under the terms of a contract, including, but not limited to, government contracts and construction contracts, classified as other.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 225
-SubTopic 10
-Section S99
-Paragraph 2
-Subparagraph (SX 210.5-03.1)
-URI http://asc.fasb.org/extlink&oid=63488584&loc=d3e20235-122688

+ Details

Name:	us-gaap_ContractsRevenue
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration

- Definition

The amount of receivables that are derived from government contracts.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 912
-SubTopic 310
-Section 45
-Paragraph 1
-URI http://asc.fasb.org/extlink&oid=68054760&loc=d3e55295-109406

+ Details

Name:	us-gaap_GovernmentContractReceivable
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	debit
Period Type:	instant

- Definition

The equity interest of noncontrolling shareholders, partners or other equity holders in consolidated entity.

+ References

No definition available.

+ Details

Name:	us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners
Namespace Prefix:	us-gaap_
Data Type:	num:percentItemType
Balance Type:	na
Period Type:	instant

- Details

Name:	us-gaap_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis=nvax_EquityMethodInvesteeOneMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=nvax_HhsBardaContractAwardMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=nvax_HhsBardaOptionForAdditionalPeriodMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=nvax_BillMelindaGatesFoundationMember
Namespace Prefix:
Data Type:	na
Balance Type:
Period Type:

- Details

Name:	us-gaap_TypeOfArrangementAxis=nvax_CplBiologicalsPrivateLimitedMember
Namespace Prefix:
Data Type:	na
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Period Type:

U.S. Government Agreement, Collaboration and Joint Venture (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		6 Months Ended		10 Months Ended	65 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2015	Jun. 30, 2016	Jun. 30, 2016	Sep. 30, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contracts Revenue			$ 134	$ 13,720	$ 2,080	$ 22,966		$ 113,600
Cadila [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Joint Venture Percentage Owned By Others			80.00%		80.00%		80.00%	80.00%
HHS BARDA Contract [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Government Contract Receivable									$ 97,000
Increase in funding for recovery of additional costs under contract		$ 7,700
HHS BARDA Option for Additional Period [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Government Contract Receivable									$ 70,000
Bill Melinda Gates Foundation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contracts Revenue			$ 1,700		$ 3,300		$ 4,900
Grant agreement	$ 89,100
CPL Biologicals Private Limited [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage			20.00%		20.00%		20.00%	20.00%