Accrued Expenses - Schedule of Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Payables and Accruals [Abstract]
Research and development	$ 11,844	$ 8,144
Commercial	1,027	0
Employee compensation	9,932	7,975
Professional services	976	621
Accrued purchases	119	351
Other	997	1,118
Total accrued expenses	$ 24,895	$ 18,209

Carrying value as of the balance sheet date of obligations incurred and payable, pertaining to costs that are statutory in nature, are incurred on contractual obligations, or accumulate over time and for which invoices have not yet been received or will not be rendered. Examples include taxes, interest, rent and utilities. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

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- Definition

Carrying value as of the balance sheet date of obligations incurred through that date and payable for professional fees, such as for legal and accounting services received. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
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-Section S99
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-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 8
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6935-107765

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Total of the carrying values as of the balance sheet date of obligations incurred through that date and payable for obligations related to services received from employees, such as accrued salaries and bonuses, payroll taxes and fringe benefits. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).

+ References

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- Definition

Amount of expenses incurred but not yet paid classified as other, due within one year or the normal operating cycle, if longer.

+ References

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section S99
-Paragraph 1
-Subparagraph (SX 210.5-02.20)
-URI http://asc.fasb.org/extlink&oid=6877327&loc=d3e13212-122682

Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
-Publisher FASB
-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
-Paragraph 6
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6911-107765

Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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-Section 45
-Paragraph 9
-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e7018-107765

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-Name Accounting Standards Codification
-Topic 210
-SubTopic 10
-Section 45
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-URI http://asc.fasb.org/extlink&oid=118951113&loc=d3e6935-107765

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- References

No definition available.

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- Definition

Accrued Commercial Expense, Current

+ References

No definition available.

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- Definition

Accrued Purchases

+ References

No definition available.

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- Definition

Represents the carrying value, as of the balance sheet date, of obligations incurred through that date and payable for research and development expense. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle, if longer).

+ References

No definition available.

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