Summary of Significant Accounting Policies and Other Information - Narrative (Details) |
1 Months Ended | 3 Months Ended | 9 Months Ended | |||
|---|---|---|---|---|---|---|
|
Apr. 30, 2020
USD ($)
|
Sep. 30, 2020
USD ($)
board_member
|
Sep. 30, 2019
USD ($)
|
Sep. 30, 2020
USD ($)
board_member
segment
|
Sep. 30, 2019
USD ($)
|
Dec. 31, 2019
USD ($)
|
|
| Concentration Risk [Line Items] | ||||||
| Number of board members | board_member | 3 | 3 | ||||
| Number of operating segments | segment | 1 | |||||
| Research and development and engineering expenses | $ 6,200,000 | $ 5,900,000 | $ 18,200,000 | $ 17,400,000 | ||
| Outstanding letters of credit amount | 2,800,000 | 2,800,000 | ||||
| Restricted cash | $ 3,299,000 | $ 0 | $ 3,299,000 | $ 0 | $ 0 | |
| Revolving Credit Facility | Standard Chartered Bank Credit Agreement | ||||||
| Concentration Risk [Line Items] | ||||||
| Borrowing amount | $ 130,000,000.0 | |||||
| Maturity period prior to the final maturity of unsecured senior notes | 60 days | |||||
| Extension fee percentage | 0.25% | |||||