Summary of Significant Accounting Policies - Reconciliation of Cash and Cash Equivalents and Restricted Cash (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Summary of Significant Accounting Policies Details [Line Items]
Cash and cash equivalents	$ 15,508	$ 9,705
Restricted Cash	206	2,892
Cash, cash equivalents and restricted cash in the statement of cash flows	16,182	13,069	$ 27,165
Other Assets
Summary of Significant Accounting Policies Details [Line Items]
Restricted Cash	468	$ 472
2019 Notes
Summary of Significant Accounting Policies Details [Line Items]
Restricted Cash	$ 2,700