Trust Account and Fair Value Measurement (Details) - USD ($) |
9 Months Ended | 12 Months Ended |
|---|---|---|
Sep. 30, 2019 |
Dec. 31, 2018 |
|
| Assets: | ||
| Carrying value | $ 306,852,000 | $ 304,035,000 |
| Gross Unrealized Holding Gain (Loss) | 80,000 | (7,000) |
| Quoted Price Prices in Active Markets (Level 1) [Member] | ||
| Assets: | ||
| Carrying value | 306,932,000 | 304,028,000 |
| Cash and money market [Member] | ||
| Assets: | ||
| Carrying value | 1,000 | 1,000 |
| Gross Unrealized Holding Gain (Loss) | ||
| Cash and money market [Member] | Quoted Price Prices in Active Markets (Level 1) [Member] | ||
| Assets: | ||
| Carrying value | 1,000 | 1,000 |
| U.S. government treasury bills [Member] | ||
| Assets: | ||
| Carrying value | 306,851,000 | 304,034,000 |
| Gross Unrealized Holding Gain (Loss) | 80,000 | (7,000) |
| U.S. government treasury bills [Member] | Quoted Price Prices in Active Markets (Level 1) [Member] | ||
| Assets: | ||
| Carrying value | $ 306,931,000 | $ 304,027,000 |