Commitments and Contingencies - Additional Lease Disclosures and Other Commitments and Contingencies (Details) - USD ($) $ in Thousands	12 Months Ended
Dec. 31, 2020	Dec. 31, 2019
Operating Cash Flows Supplemental Information:
Cash paid for amounts included in the measurement of the operating lease liabilities	$ 507	$ 515
Right-of-use assets obtained in exchange for operating lease obligations	226	$ 1,647
Future payments of operating lease liabilities, ASC 842
2021	171
Total lease payments	171
Less imputed interest and amortization differences	(3)
Present value of operating lease liabilities	168
Future minimum expected lease payments under non-cancelable operating leases, ASC 840
Total	743
2021	743
Other contractual commitments
Total	58,166
2021	14,059
2022	12,569
2023	12,838
2024	9,350
2025	9,350
Future minimum contractual obligations and commitments
Total	58,909
2021	14,802
2022	12,569
2023	12,838
2024	9,350
2025	9,350
Other Commitments and Contingencies
Contingent liabilities	$ 0

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