Grant agreement

No definition available.

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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

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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

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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

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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

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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:
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- 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
Balance Type:
Period Type:

- Details

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- Details

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Collaboration, U.S. Government Agreement and Joint Venture (Narrative) (Details) - USD ($) $ in Thousands	1 Months Ended		3 Months Ended		19 Months Ended
	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2017	Mar. 31, 2016	Mar. 31, 2017	Sep. 30, 2014
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contracts Revenue			$ 0	$ 1,946
Cadila [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Joint Venture Percentage Owned By Others			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]
Grant agreement	$ 89,100
CPL Biologicals Private Limited [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Ownership percentage			20.00%		20.00%
Minimum [Member] \| Bill Melinda Gates Foundation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contracts Revenue			$ 5,500
Maximum [Member] \| Bill Melinda Gates Foundation [Member]
Collaborative Arrangements and Non-collaborative Arrangement Transactions [Line Items]
Contracts Revenue					$ 18,000