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Term Loan Obligations (Details) - USD ($) |  |  |  | 12 Months Ended
--- | --- | --- | --- | ---
Mar. 29, 2020 | Mar. 28, 2020 | May 29, 2015 | Dec. 31, 2021 | Dec. 31, 2020
Debt Instrument [Line Items] |  |  |  |  |
Warrant exercise price (in dollars per share) |  |  |  |  | $ 2.25
Interest expense |  |  |  | $ 932,000 | $ 1,107,000
Non-cash amortization |  |  |  | $ 500,000 | $ 600,000
LIBOR [Member] | Interest Rate Floor [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Basis variable rate |  |  | 1.00% |  |
Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Origination Date |  |  |  | May 29, 2015 | May 29, 2015
Original Loan Amount |  |  | $ 17,700,000 | $ 17,700,000 | $ 17,700,000
Basis variable rate |  |  | 7.95% |  |
Maturity date | Jun. 01, 2024 | Sep. 01, 2021 | May 01, 2021 |  |
Fees amount associated with loan |  |  | $ 3,200,000 | $ 3,200,000 |
Number of shares callable by warrants (in shares) |  |  | 188 |  |
Warrant exercise price (in dollars per share) |  |  | $ 5,175 |  |
Date from which warrants are exercisable |  |  |  | Nov. 30, 2015 |
Warrant expiration date |  |  |  | May 29, 2025 |
Minimum liquidity covenant |  |  |  | $ 2,000,000.0 |
Debt principal repayment start date | May 01, 2021 | May 01, 2020 |  |  |
Prepayments of term loan | $ 5,000,000.0 |  |  |  |
Related final payment | 300,000 |  |  |  |
Term loan, remaining amount | 4,300,000 |  |  |  |
Amendment fee | $ 1,000,000.0 |  |  |  |
Debt Instrument, Covenant Compliance |  |  |  | the Company was in compliance with all of the debt covenants under the Loan and Security Agreement. |
Term Loan [Member] | Loan and Security Agreement [Member] | Sale of the Japanese Subsidiary and Certain Assets [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Payments for principal, interest and fees |  |  | $ 3,100,000 |  |
Minimum [Member] | Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Interest rate |  |  | 8.95% |  |
Maximum [Member] | Term Loan [Member] |  |  |  |  |
Debt Instrument [Line Items] |  |  |  |  |
Original Loan Amount |  |  |  | $ 3,000,000 |
Long Term Debt Outstanding Threshold Amount |  |  |  | $ 4,000,000.0 |

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