| Cover | Nov. 12, 2021 |
| Entity Addresses [Line Items] | |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Nov. 12, 2021 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-39248 |
| Entity Registrant Name | Oncology Institute, Inc. |
| Entity Central Index Key | 0001799191 |
| Entity Tax Identification Number | 84-3562323 |
| Entity Incorporation, State or Country Code | DE |
| Entity Address, Address Line One | 18000 Studebaker Rd |
| Entity Address, Address Line Two | Suite 800 |
| Entity Address, City or Town | Cerritos |
| Entity Address, State or Province | CA |
| Entity Address, Postal Zip Code | 90703 |
| City Area Code | 213 |
| Local Phone Number | 760-1328 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | true |
| Elected Not To Use the Extended Transition Period | false |
| Entity Information, Former Legal or Registered Name | DFP Healthcare Acquisitions Corp. |
| Common Stock [Member] | |
| Entity Addresses [Line Items] | |
| Title of 12(b) Security | Common Stock, $0.0001 par value per share |
| Trading Symbol | TOI |
| Security Exchange Name | NYSE |
| Warrant [Member] | |
| Entity Addresses [Line Items] | |
| Title of 12(b) Security | Warrants to purchase common stock |
| Trading Symbol | TOIIW |
| Security Exchange Name | NYSE |
| Former Address [Member] | |
| Entity Addresses [Line Items] | |
| Entity Address, Address Line One | 345 Park Avenue South |
| Entity Address, City or Town | New York |
| Entity Address, State or Province | NY |
| Entity Address, Postal Zip Code | 10010 |
