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

Summary of Significant Accounting Policies - Concentrations (Details)

v3.21.1
Summary of Significant Accounting Policies - Concentrations (Details) - Blade Urban Air Mobility [Member]
3 Months Ended 6 Months Ended 12 Months Ended
Mar. 31, 2021
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Mar. 31, 2020
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Mar. 31, 2021
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Mar. 31, 2020
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Sep. 30, 2020
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customer
Sep. 30, 2019
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customer
Concentration Risk [Line Items]            
Risk concentration percentage 10.00% 12.00% 10.00% 15.00% 10.00% 10.00%
Number of customers | customer         0 0
Number of vendor 0 1 0 1   2
Trade receivables            
Concentration Risk [Line Items]            
Risk concentration percentage           75.00%
Purchases from vendors            
Concentration Risk [Line Items]            
Risk concentration percentage         12.00%  
Number of customers         3  
Number of vendor 4       1 3
Customer one            
Concentration Risk [Line Items]            
Risk concentration percentage           30.00%
Customer one | Trade receivables            
Concentration Risk [Line Items]            
Risk concentration percentage 28.00%       36.00%  
Customer one | Purchases from vendors            
Concentration Risk [Line Items]            
Risk concentration percentage           15.00%
Customer two            
Concentration Risk [Line Items]            
Risk concentration percentage           11.00%
Customer two | Trade receivables            
Concentration Risk [Line Items]            
Risk concentration percentage 23.00%       29.00%  
Customer two | Purchases from vendors            
Concentration Risk [Line Items]            
Risk concentration percentage           15.00%
Customer three | Trade receivables            
Concentration Risk [Line Items]            
Risk concentration percentage 17.00%       10.00%  
Customer three | Purchases from vendors            
Concentration Risk [Line Items]            
Risk concentration percentage           11.00%
Customer four | Purchases from vendors            
Concentration Risk [Line Items]            
Risk concentration percentage 14.00%          
Vendor concentration            
Concentration Risk [Line Items]            
Risk concentration percentage     62.00% 26.00% 26.00%  
Number of vendor     1 1 1