Fair Value of Financial Instruments - Recorded Amount of Assets and Liabilities Measured at Fair Value on a Recurring Basis (Parenthetical) (Details) - USD ($) |
3 Months Ended | |
---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
|
Equity Warrant Assets | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Equity warrant assets, fair value | $ 21,000 | $ 164,000 |
Gain (loss) on derivative, net | 385,000 | (32,000) |
Municipal bonds | ||
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | ||
Fair value adjustment gain (loss) | $ 0 | $ 1,000 |