Indebtedness - Debt (Details) $ in Thousands	Dec. 31, 2022 USD ($)
Indebtedness
Debt, Current	$ 57
Debt, Non current	221
NEBT Loan
Indebtedness
Debt, Current	13
Debt, Non current	31
RETOS 2015 Loan
Indebtedness
Debt, Current	44
Debt, Non current	$ 190

Amount, excluding unamortized premium (discount) and debt issuance cost, of long-term debt. Excludes lease obligation.

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Name:	us-gaap_LongTermDebt
Namespace Prefix:	us-gaap_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant