Registration of securities issued in business combination transactions

RELATED PARTY TRANSACTIONS (Q3) (Details)

v3.21.4
RELATED PARTY TRANSACTIONS (Q3) (Details) - USD ($)
3 Months Ended 9 Months Ended 12 Months Ended
Jul. 29, 2021
Feb. 21, 2021
Aug. 24, 2020
Aug. 14, 2020
Feb. 06, 2020
Jan. 10, 2020
Sep. 30, 2021
Sep. 30, 2020
Sep. 30, 2021
Sep. 30, 2020
Dec. 31, 2020
Related Party Transaction [Line Items]                      
Repayment of related party debt                   $ 140,671 $ 140,671
General and administrative services expense per month       $ 15,000              
Proceeds held in trust account to repay working capital loans                 $ 0    
Related party transaction Converted notes Price per share upon consummation of a Business Combination                 $ 10.00   $ 10.00
Unsecured promissory note                      
Related Party Transaction [Line Items]                      
Borrowings principal amount           $ 300,000          
Due to related parties     $ 140,671                
Maximum                      
Related Party Transaction [Line Items]                      
Related party transaction Converted notes upon consummation of a Business Combination                 $ 1,000,000.0   $ 1,000,000
Sponsor [Member]                      
Related Party Transaction [Line Items]                      
Number of units sold (in shares)         5,750,000            
Stock dividend         0.15            
Number of shares, common stock subject to forfeiture     750,000                
Shares owned by initial stock holders (in percentage)           22.03%          
Stock price trigger to transfer, assign or sell any shares or warrants of the company, after the completion of the initial business combination (in dollars per share)           $ 12.00          
Threshold trading days for transfer, assign or sale of shares or warrants, after the completion of the initial business combination           20 days          
Threshold consecutive trading days for transfer, assign or sale of shares or warrants, after the completion of the initial business combination           30 days          
Related party committed loan amount to consummate business combination $ 1,000,000                    
Sponsor [Member] | Class B Common Stock                      
Related Party Transaction [Line Items]                      
Number of units sold (in shares)           5,000,000          
Proceeds from issuance of shares           $ 25,000          
Sponsor [Member] | Maximum                      
Related Party Transaction [Line Items]                      
Number of shares, common stock subject to forfeiture           750,000          
Related party committed loan amount to consummate business combination $ 250,000 $ 750,000                  
Accounts Payable and Accrued Liabilities                      
Related Party Transaction [Line Items]                      
Fees for administrative support             $ 45,000 $ 30,000 $ 135,000 $ 30,000 $ 66,774