Investments - Summary of Proceeds and Realized Gains and Losses Classified as Trading Securities (Details) - Trading Securities - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Proceeds and realized gains and losses recognized | |||
| Sale Proceeds | $ 2,749 | $ 2,772 | $ 5,166 |
| Realized Gains | 22 | 37 | 159 |
| Realized losses | $ (71) | $ (73) | $ (34) |