v3.24.2
CONVERTIBLE PROMISSORY NOTES AND WARRANTS, Summary of Convertible Promissory Notes (Q1) (Details) - USD ($)
 3 Months Ended 12 Months Ended
Mar. 31, 2024
Dec. 31, 2023
Dec. 31, 2022
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Face amount $ 98,258,000 $ 40,700,000  
Convertible Promissory Notes 1-7 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Face amount $ 5,340,000 $ 5,340,000 $ 5,340,000
Debt maturity term 24 months 24 months  
Accrued interest rate 5.00% 5.00%  
Debt instrument, convertible, conversion price (in dollars per share) $ 4 $ 4  
Convertible Promissory Notes 1-2 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible conversion price percentage of initial public offering stock price 40.00% 40.00%  
Convertible Promissory Notes 3-7 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible conversion price percentage of initial public offering stock price 40.00% 40.00%  
Convertible Promissory Notes 8-12 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Face amount $ 17,500,000 $ 17,500,000 $ 17,500,000
Convertible Promissory Notes 8-12 [Member] | Merger agreement with TMTG [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible price minimum percentage of stock price applied 50.00% 50.00%  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Price One [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share) $ 25 $ 25  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Price Two [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share) 21 21  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Price Three [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share) 20 20  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Threshold Stock Price Trigger One [Member] | Merger agreement with TMTG [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible stock price trigger (in dollars per share) 50 50  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Threshold Stock Price Trigger Two [Member] | Merger agreement with TMTG [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible stock price trigger (in dollars per share) 42 42  
Convertible Promissory Notes 8-12 [Member] | Debt Instrument Conversion Threshold Stock Price Trigger Three [Member] | Merger agreement with TMTG [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument convertible stock price trigger (in dollars per share) $ 40 $ 40  
Convertible Promissory Notes 8-12 [Member] | Minimum [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt maturity term 18 months 18 months  
Accrued interest rate 5.00% 5.00%  
Convertible Promissory Notes 8-12 [Member] | Minimum [Member] | Merger agreement with TMTG [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share) $ 10 $ 10  
Convertible Promissory Notes 8-12 [Member] | Maximum [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt maturity term 36 months 36 months  
Accrued interest rate 10.00% 10.00%  
Convertible Promissory Notes 13-19 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Face amount $ 18,360,000 $ 18,360,000  
Debt maturity term 18 months 18 months  
Convertible Promissory Notes 13-19 [Member] | Debt Instrument Conversion Price One [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share)   $ 25  
Convertible Promissory Notes 13-19 [Member] | Debt Instrument Conversion Price Two [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Debt instrument, convertible, conversion price (in dollars per share)   $ 21  
Convertible Promissory Notes 13-19 [Member] | Minimum [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Accrued interest rate 5.00% 5.00%  
Debt instrument, convertible, conversion price (in dollars per share) $ 21    
Convertible Promissory Notes 13-19 [Member] | Maximum [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Accrued interest rate 10.00% 10.00%  
Debt instrument, convertible, conversion price (in dollars per share) $ 25    
Convertible Promissory Notes 20-23 [Member]      
Debt, Long-Term and Short-Term, Combined Amount [Abstract]      
Face amount $ 7,955,000    
Debt maturity term 18 months    
Accrued interest rate 10.00%    
Debt instrument, convertible, conversion price (in dollars per share) $ 10    
Debt instrument convertible price minimum percentage of stock price applied 50.00%