Commitment and Contingencies - Build-to-Suit Lease Financing Obligation (Details) $ in Thousands	Sep. 30, 2019 USD ($)
Build-to-Suit Lease
2019 (remaining three months)	$ 659
2020	2,673
2021	2,753
2022	2,355
2023	0
Total minimum lease payments	$ 8,440

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Build-To-Suit Leases, Future Minimum Payments, Due In Four Years

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Build-To-Suit Leases, Future Minimum Payments, Due In Three Years

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