| Cover Page | Aug. 26, 2021 |
| Entity Information [Line Items] | |
| Document Type | 8-K |
| Document Period End Date | Aug. 26, 2021 |
| Entity Registrant Name | TRIUMPH BANCORP, INC. |
| Entity Incorporation, State or Country Code | TX |
| Entity File Number | 001-36722 |
| Entity Tax Identification Number | 20-0477066 |
| Entity Address, Address Line One | 12700 Park Central Drive |
| Entity Address, Address Line Two | Suite 1700 |
| Entity Address, City or Town | Dallas |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 75251 |
| City Area Code | 214 |
| Local Phone Number | 365-6900 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Entity Emerging Growth Company | false |
| Amendment Flag | false |
| Entity Central Index Key | 0001539638 |
| Common Stock | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Common stock, par value $0.01 per share |
| Trading Symbol | TBK |
| Security Exchange Name | NASDAQ |
| Series C Preferred Stock | |
| Entity Information [Line Items] | |
| Title of 12(b) Security | Depositary Shares Each Representing a 1/40th Interest in a Share of 7.125% Series C Fixed-Rate Non-Cumulative Perpetual Preferred Stock |
| Trading Symbol | TBKCP |
| Security Exchange Name | NASDAQ |
