General form of registration statement for all companies including face-amount certificate companies

Warrants - Series F warrant liability (Q1) (Details)

v3.21.1
Warrants - Series F warrant liability (Q1) (Details) - USD ($)
$ / shares in Units, $ in Millions
 1 Months Ended 3 Months Ended 8 Months Ended 12 Months Ended
Nov. 30, 2020
Jul. 20, 2020
Jun. 24, 2020
Mar. 17, 2020
Dec. 19, 2019
Nov. 04, 2019
Oct. 31, 2020
Sep. 30, 2020
Jun. 30, 2020
Mar. 31, 2021
Dec. 31, 2019
Dec. 31, 2020
Class of Warrant or Right [Line Items]                        
Issued (in shares) 400,000 200,000 1,000,000 1,003,232 937,500 11,000   570,258 1,990,624 3,288,400 17,414,030 49,928,469
Warrants, exercise price (in dollars per share) $ 1.00 $ 1.05 $ 1.25 $ 1.62 $ 5.00 $ 5.00   $ 0.65 $ 0.75      
Term of warrants 72 months   84 months   24 months 24 months            
Series F Convertible Preferred Stock                        
Class of Warrant or Right [Line Items]                        
Adjustment to additional paid-in capital for discount on preferred stock             $ 14.6          
Series F Warrants                        
Class of Warrant or Right [Line Items]                        
Issued (in shares)             43,403,130          
Warrants, exercise price (in dollars per share)             $ 0.75          
Term of warrants             72 months