| Cover | Jun. 28, 2023 |
| Document Type | 8-K |
| Amendment Flag | false |
| Document Period End Date | Jun. 28, 2023 |
| Current Fiscal Year End Date | --12-31 |
| Entity File Number | 001-39958 |
| Entity Registrant Name | TRINITY CAPITAL INC. |
| Entity Central Index Key | 0001786108 |
| Entity Tax Identification Number | 35-2670395 |
| Entity Incorporation, State or Country Code | MD |
| Entity Address, Address Line One | 1 N. 1st Street |
| Entity Address, Address Line Two | 3rd Floor |
| Entity Address, City or Town | Phoenix |
| Entity Address, State or Province | AZ |
| Entity Address, Postal Zip Code | 85004 |
| City Area Code | 480 |
| Local Phone Number | 374-5350 |
| 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 |
| Common Stock, par value $0.001 per share | |
| Title of 12(b) Security | Common Stock, par value $0.001 per share |
| Trading Symbol | TRIN |
| Security Exchange Name | NASDAQ |
| 7.00% Notes due 2025 | |
| Title of 12(b) Security | 7.00% Notes due 2025 |
| Trading Symbol | TRINL |
| Security Exchange Name | NASDAQ |
