RELATED PARTY TRANSACTIONS, Promissory Note (Q1) (Details) - USD ($) |
3 Months Ended | 7 Months Ended | 12 Months Ended | |||
|---|---|---|---|---|---|---|
Mar. 31, 2021 |
Mar. 31, 2020 |
Dec. 31, 2019 |
Dec. 31, 2020 |
Feb. 18, 2021 |
Jun. 10, 2019 |
|
| Related Party Transactions [Abstract] | ||||||
| Amount drawn | $ 200,000 | $ 0 | $ 237,470 | $ 0 | ||
| Sponsor [Member] | Promissory Note [Member] | ||||||
| Related Party Transactions [Abstract] | ||||||
| Aggregate principal amount of note | $ 237,470 | |||||
| Amount drawn | $ 200,000 | |||||
| Sponsor [Member] | Promissory Note [Member] | Maximum [Member] | ||||||
| Related Party Transactions [Abstract] | ||||||
| Aggregate principal amount of note | $ 750,000 | |||||