| Document and Entity Information | Jun. 16, 2020 |
| Cover [Abstract] | |
| Amendment Flag | false |
| Entity Central Index Key | 0001539638 |
| Document Type | 8-K |
| Document Period End Date | Jun. 16, 2020 |
| Entity Registrant Name | TRIUMPH BANCORP, INC. |
| Entity Incorporation State 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 |
| Security 12b Title | Common stock, par value $0.01 per share |
| Trading Symbol | TBK |
| Security Exchange Name | NASDAQ |
