Quarterly report pursuant to Section 13 or 15(d)

Reverse Recapitalization - Additional Information (Detail)

v3.21.2
Reverse Recapitalization - Additional Information (Detail)
$ / shares in Units, $ in Thousands
1 Months Ended 9 Months Ended
Aug. 16, 2021
shares
Aug. 31, 2021
USD ($)
$ / shares
shares
Sep. 30, 2021
USD ($)
$ / shares
Sep. 30, 2020
USD ($)
Common stock per share | $ / shares     $ 0.0001  
Proceeds from issuance initial public offering   $ 264,823    
Cash held in trust account   230,027    
Proceeds from issuance or sale of equity   210,204    
Proceeds from issuance of financial Services obligations   245,000    
Payments of merger related costs   38,653    
Payments of financing costs     $ 4,293 $ 183
Additional Paid In Capital [Member]        
Payments of financing costs   32,062    
Selling, General and Administrative Expenses [Member]        
Payments of financing costs   $ 6,591    
Old Spire Options [Member]        
Exchange ratio of common stock   1.8282    
Number of consecutive trading days for determining share price   20 days    
Number of trading days for determining share price   30 days    
Closing date of warrants   5 years    
Class of warrants and rights exchange ratio   1.7058    
First Tranches Share Trading Price [Member]        
Share price | $ / shares   $ 13.00    
Second Tranches Share Trading Price [Member]        
Share price | $ / shares   16.00    
Third Tranches Share Trading Price [Member]        
Share price | $ / shares   19.00    
Fourth Tranches Share Trading Price [Member]        
Share price | $ / shares   $ 22.00    
PIPE Investors [Member] | PIPE Subscription Agreements [Member]        
Shares issued during the year, subscribed | shares   24,500,000    
Shares issued during the year, aggregate purchase price   $ 245,000    
Payments of stock issuance costs   $ 7,142    
Old Spire Warrants [Member]        
Class of warrant outstanding | shares 909,798      
Old Spire Convertible Notes [Member]        
Conversion ratio of convertible notes 2.4808      
2021 Old Spire Notes [Member]        
Conversion ratio of convertible notes 13.6466      
Old Spire Series A Convertible Preferred Stock [Member]        
Outstanding shares | shares 12,671,911      
Common stock, conversion basis one-to-one basis      
Old Spire Series B Convertible Preferred Stock [Member]        
Outstanding shares | shares 4,869,754      
Common stock, conversion basis one-to-one basis      
Old Spire Series C Convertible Preferred Stock [Member]        
Outstanding shares | shares 7,592,402      
Common stock, conversion basis one-to-one basis      
New Spire Class A Common stock [Member]        
Common stock per share | $ / shares   $ 0.0001    
Exchange ratio of common stock   1.7058    
Shares issued, price per share | $ / shares   $ 0.1236    
New Spire Class B Common Stock [Member] | Old Spire Founders [Member]        
Common stock per share | $ / shares   $ 0.0001