Prepaid Expenses and Other Assets (Details) - USD ($) $ in Thousands	Mar. 31, 2023	Dec. 31, 2022
Prepaid Expenses and Other Assets
Prepaid insurance	$ 483	$ 488
Current portion of deferred offering costs	21	45
Recoupable deposits and other	492	609
Prepaid expenses and other assets	996	1,142
Receivables for reimbursement of costs	$ 74,000	$ 196,000