Quarterly report pursuant to Section 13 or 15(d)

Reverse Recapitalization - Summary of Number of Shares of Common Stock Issued (Detail)

v3.22.2.2
Reverse Recapitalization - Summary of Number of Shares of Common Stock Issued (Detail)
Sep. 30, 2021
shares
Old Spire Common Stock (excluding Founders)  
Class of Stock [Line Items]  
Common stock, Issued 6,405,302
Old Spire Convertible Preferred Stock  
Class of Stock [Line Items]  
Common stock, Issued 42,873,636
Old Spire Convertible Notes  
Class of Stock [Line Items]  
Common stock, Issued 37,034,620
Old Spire Warrants (excluding EIB warrants)  
Class of Stock [Line Items]  
Common stock, Issued 672,355
Total Class A common shares to Old Spire stockholders (excluding Founders)  
Class of Stock [Line Items]  
Common stock, Issued 86,985,913
New Spire Class A Common Stock issued to Old Spire Founders  
Class of Stock [Line Items]  
Common stock, Issued 12,058,614
New Spire Class A Common Stock issued to PIPE Investors  
Class of Stock [Line Items]  
Common stock, Issued 24,500,000
New Spire Class A Common Stock held by public stockholders  
Class of Stock [Line Items]  
Common stock, Issued 1,979,515
New Spire Class A Common Stock issued to FP Lenders  
Class of Stock [Line Items]  
Common stock, Issued 2,468,492
New Spire Class A Common Stock resulting from conversion of NavSight Class B Common Stock  
Class of Stock [Line Items]  
Common stock, Issued 5,750,000
Total Shares of New Spire Class A Common Stock  
Class of Stock [Line Items]  
Common stock, Issued 133,742,534
New Spire Class B Common Stock issued to Old Spire Founders  
Class of Stock [Line Items]  
Common stock, Issued 12,058,614
Total Shares of New Spire Common Stock  
Class of Stock [Line Items]  
Common stock, Issued 145,801,148