| Document and Entity Information | Aug. 31, 2021 |
| Document And Entity Information [Line Items] | |
| Entity Address, State or Province | DC |
| Amendment Flag | false |
| Entity Central Index Key | 0001825024 |
| Document Type | 8-K |
| Document Period End Date | Aug. 31, 2021 |
| Entity Registrant Name | Supernova Partners Acquisition Company, Inc. |
| Entity Incorporation State Country Code | DE |
| Entity File Number | 001-39641 |
| Entity Tax Identification Number | 85-2800538 |
| Entity Address, Address Line One | 4301 50th Street NW |
| Entity Address, Address Line Two | Suite 300 |
| Entity Address, Address Line Three | PMB 1044 |
| Entity Address, City or Town | Washington |
| Entity Address, Postal Zip Code | 20016 |
| City Area Code | (202) |
| Local Phone Number | 918-7050 |
| 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 |
| Units Each Consisting Of One Share Of Class A Common Stock 0.0001 Par Value And One Third Of One Warrant To Purchase One Class A Common Stock 2 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Units, each consisting of one share of Class A common stock, $0.0001 par value, and one-third of one warrant to purchase one Class A common stock |
| Trading Symbol | SPNV.U |
| Security Exchange Name | NYSE |
| Common Class A [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Class A common stock, par value $0.0001 per share |
| Trading Symbol | SPNV |
| Security Exchange Name | NYSE |
| Warrants To Purchase Class A Common Stock At An Exercise Price Of 11.50 Per Share 1 [Member] | |
| Document And Entity Information [Line Items] | |
| Security 12b Title | Warrants to purchase Class A common stock, at an exercise price of $11.50 per share |
| Trading Symbol | SPNV WS |
| Security Exchange Name | NYSE |
