Liability Related to Sale of Future Royalties - Rollforward of Liability Related to Sale of Future Royalties (Details) - USD ($) $ in Thousands		6 Months Ended
Feb. 25, 2021	Jun. 30, 2021	Jun. 30, 2020
Contractual Arrangement, Royalties Agreement, Liability, Noncurrent [Roll Forward]
Liability related to sale of future royalties, net — beginning balance		$ 0
Proceeds from sale of future royalties, net	$ 44,800	44,783	$ 0
MTPC royalties payable		(116)
Non-cash interest expense recognized		4,427	$ 0
Liability related to sale of future royalties, net — ending balance	$ 44,800	$ 49,094

Contractual Arrangement, Royalties Agreement, Liability, Noncurrent

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Contractual Arrangement, Royalties Agreement, Liability, Noncurrent

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Contractual Arrangement, Royalties Agreement, Noncash Interest Expense (Income)

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Contractual Arrangement, Royalties Agreement, Royalties, Earned And Payable

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Proceeds From Contractual Arrangement, Royalties Agreement, Sale Of Future Royalties

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