Fair Value of Financial Instruments - Fair value measurements on a recurring basis (Details) - USD ($) $ in Thousands |
Jun. 30, 2022 |
Dec. 31, 2021 |
|---|---|---|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Investments in available-for-sale-securities | $ 220 | $ 219 |
| Fair Value, Inputs, Level 1 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Investments in available-for-sale-securities | 220 | 219 |
| Fair Value, Recurring [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Investments in available-for-sale-securities | 220 | 219 |
| Total | 220 | 219 |
| Fair Value, Recurring [Member] | Fair Value, Inputs, Level 1 [Member] | ||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
| Investments in available-for-sale-securities | 220 | 219 |
| Total | $ 220 | $ 219 |