Leases	9 Months Ended
Leases	Sep. 30, 2021
Leases [Abstract]
Leases	Leases During the third quarter of 2021, the Company entered into a supply agreement with a CMO that modified existing short-term embedded leases under ASC Topic 842, Leases (“ASC 842”) as the Company continues to have the exclusive use of, and control over, a portion of manufacturing facilities and equipment of the supplier during the contractual term of the new arrangement. The modifications did not result in a change in lease classification and, in accordance with the Company's election to apply the practical expedient in ASC 842, it did not recognize a Right-Of-Use ("ROU") asset or lease liability but instead, will recognize lease payments as an expense on a straight-line basis over the modified lease term and variable lease payments that do not depend on an index or rate, are recognized as an expense in the period in which the variable lease costs are incurred based on performance or usage in accordance with contractual agreements. During the second quarter of 2021, the Company evaluated the impact of changes in facts and circumstances on its CMOs and contract development and manufacturing organizations agreements that had previously been determined to represent embedded lease arrangements. The Company concluded that the impact resulted in the modification of existing leases and, in accordance with its policy, the Company remeasured and reallocated the remaining consideration in the contracts and reassessed the lease classification as of the effective date of the modification. As a result, the Company recognized a ROU asset and a corresponding long-term operating lease liability of $11.4 million on the remeasurement of one of its long-term supply agreements using an incremental borrowing rate of 6.5%. The Company expensed the ROU asset since it relates to research and development activities for the development of NVX-CoV2373 for which the Company does not have an alternative future use. Modifications to leases with a lease term of 12 months or less at the commencement date did not result in a change in lease classification and in accordance with the Company's election, it applied the practical expedient in ASC 842, as described above. During the three and nine months ended September 30, 2021, the Company recognized a short-term lease expense of $111.3 million and $325.5 million, respectively, related to its embedded leases and expensed $4.4 million and $17.1 million, respectively, of ROU assets that represented assets acquired for research and development activities that did not have an alternative future use at the commencement of lease. The Company recognized a short-term lease expense of $19.4 million related to embedded leases and expensed $187.2 million of ROU assets that represented assets acquired for research and development activities that did not have an alternative future use at the commencement of lease during the three and nine months ended September 30, 2020. During the three and nine months ended September 30, 2021, the Company recognized $1.6 million and $5.6 million of interest expenses, respectively, on its finance lease liabilities. The Company recognized $1.0 million of interest expense related to finance lease liabilities during the three and nine months ended September 30, 2020. During the nine months ended September 30, 2021, the Company entered into or extended the term of certain of its existing research and development facility and offices leases, giving rise to additional ROU assets and related operating lease liabilities of $17.8 million.
Leases	Leases During the third quarter of 2021, the Company entered into a supply agreement with a CMO that modified existing short-term embedded leases under ASC Topic 842, Leases (“ASC 842”) as the Company continues to have the exclusive use of, and control over, a portion of manufacturing facilities and equipment of the supplier during the contractual term of the new arrangement. The modifications did not result in a change in lease classification and, in accordance with the Company's election to apply the practical expedient in ASC 842, it did not recognize a Right-Of-Use ("ROU") asset or lease liability but instead, will recognize lease payments as an expense on a straight-line basis over the modified lease term and variable lease payments that do not depend on an index or rate, are recognized as an expense in the period in which the variable lease costs are incurred based on performance or usage in accordance with contractual agreements. During the second quarter of 2021, the Company evaluated the impact of changes in facts and circumstances on its CMOs and contract development and manufacturing organizations agreements that had previously been determined to represent embedded lease arrangements. The Company concluded that the impact resulted in the modification of existing leases and, in accordance with its policy, the Company remeasured and reallocated the remaining consideration in the contracts and reassessed the lease classification as of the effective date of the modification. As a result, the Company recognized a ROU asset and a corresponding long-term operating lease liability of $11.4 million on the remeasurement of one of its long-term supply agreements using an incremental borrowing rate of 6.5%. The Company expensed the ROU asset since it relates to research and development activities for the development of NVX-CoV2373 for which the Company does not have an alternative future use. Modifications to leases with a lease term of 12 months or less at the commencement date did not result in a change in lease classification and in accordance with the Company's election, it applied the practical expedient in ASC 842, as described above. During the three and nine months ended September 30, 2021, the Company recognized a short-term lease expense of $111.3 million and $325.5 million, respectively, related to its embedded leases and expensed $4.4 million and $17.1 million, respectively, of ROU assets that represented assets acquired for research and development activities that did not have an alternative future use at the commencement of lease. The Company recognized a short-term lease expense of $19.4 million related to embedded leases and expensed $187.2 million of ROU assets that represented assets acquired for research and development activities that did not have an alternative future use at the commencement of lease during the three and nine months ended September 30, 2020. During the three and nine months ended September 30, 2021, the Company recognized $1.6 million and $5.6 million of interest expenses, respectively, on its finance lease liabilities. The Company recognized $1.0 million of interest expense related to finance lease liabilities during the three and nine months ended September 30, 2020. During the nine months ended September 30, 2021, the Company entered into or extended the term of certain of its existing research and development facility and offices leases, giving rise to additional ROU assets and related operating lease liabilities of $17.8 million.