Convertible Senior Notes (Narrative) (Details) - USD ($) $ / shares in Units, $ in Millions	1 Months Ended
Jan. 25, 2016	Sep. 30, 2012
Debt Instrument [Line Items]
Debt Instrument, Face Amount		$ 2.0
Convertible Debt [Member] \| Subsequent Event [Member]
Debt Instrument [Line Items]
Debt Instrument, Face Amount	$ 325.0
Debt Instrument, Convertible, Conversion Price	$ 6.81
Stock Price Conversion Premium Based Upon	$ 5.56
Payments For Capped Call Transactions	$ 38.0
Percentage of Conversion Premium	22.50%
Cap Price on Call Transactions	$ 9.73
Debt Conversion, Converted Instrument, Type	The initial conversion rate for the Notes is 146.8213 shares of Novavax’ common stock per $1,000 principal amount of the Notes
Annual interest rate of notes (as a percent)	3.75%
Percentage of Conversion Premium with Call Transactions	75.00%

Represent cap price for per share on call transaction.

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- Definition

Represents the value of crapped call transaction.

+ References

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Percentage of conversion premium.

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- Definition

This lines represents conversion of premium of transaction in precentage.

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Per share amount received by subsidiary or equity investee for each share of common stock issued or sold in the stock transaction.

+ References

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- Definition

The type of the financial instrument that the original debt is being converted into (for example, new debt, common stock, preferred stock, etc.) in a noncash (or part noncash) transaction. "Part noncash" refers to that portion of the transaction not resulting in cash receipts or cash payments in the period.

+ References

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The price per share of the conversion feature embedded in the debt instrument.

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- Definition

Face (par) amount of debt instrument at time of issuance.

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Contractual interest rate for funds borrowed, under the debt agreement.

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- 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.

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No definition available.

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