| Document and Entity Information | Aug. 16, 2021 |
| Document Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 16, 2021 |
| Entity Registrant Name | SPIRE GLOBAL, INC. |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-39493 |
| Entity Tax Identification Number | 85-1276957 |
| Entity Address, Address Line One | 8000 Towers Crescent Drive |
| Entity Address, Address Line Two | Suite 1225 |
| Entity Address, City or Town | Vienna |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 22182 |
| City Area Code | 202 |
| Local Phone Number | 301-5127 |
| Entity Information, Former Legal or Registered Name | NavSight Holdings, Inc. |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Entity Ex Transition Period | false |
| Current Fiscal Year End Date | --12-31 |
| Amendment Flag | false |
| Entity Central Index Key | 0001816017 |
| Former Address [Member] | |
| Document Information [Line Items] | |
| Entity Address, Address Line One | 12020 Sunrise Valley Drive |
| Entity Address, Address Line Two | Suite 100 |
| Entity Address, City or Town | Reston |
| Entity Address, State or Province | VA |
| Entity Address, Postal Zip Code | 20191 |
| Class A Common Stock [Member] | |
| Document Information [Line Items] | |
| Title of each class | Class A common stock, par value $0.0001 per share |
| Trading Symbol(s) | SPIR |
| Name of each exchange on which registered | NYSE |
| Warrant [Member] | |
| Document Information [Line Items] | |
| Title of each class | Redeemable warrants, each whole warrant exercisable for one share of Class A common stock at an exercise price of $11.50 |
| Trading Symbol(s) | SPIR.WS |
| Name of each exchange on which registered | NYSE |
