Financial Instruments - Net Unrealized Positions (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Available-for-sale Securities | |||
| Net unrealized gains (losses) on available-for-sale securities, net of tax | $ 1,471 | $ 214 | $ (41) |
| Available-for-sale securities | |||
| Available-for-sale Securities | |||
| Balance | (552) | (766) | |
| Net unrealized gains (losses) on available-for-sale securities, net of tax | 1,487 | 171 | |
| Reclassifications of losses (gains) realized from sale of available-for-sale securities | (16) | 43 | |
| Increase (decrease) in other comprehensive loss | 1,471 | 214 | |
| Balance | $ 919 | $ (552) | $ (766) |