| Component: (Network and Table) | |
|---|---|
| Network | 2404404 - Disclosure - GOODWILL AND CORE DEPOSIT INTANGIBLES - Estimated Aggregate Future Amortization Expense for Core Deposit Intangibles (Details) (http://www.allegiancebank.com/role/GoodwillAndCoreDepositIntangiblesEstimatedAggregateFutureAmortizationExpenseForCoreDepositIntangiblesDetails) |
| Table | (Implied) |
| Reporting Entity [Axis] | 0001642081 (http://www.sec.gov/CIK) |
| Goodwill and Intangible Assets Disclosure [Abstract] | Period [Axis] | |
|---|---|---|
2016-12-31 | 2015-12-31 | |
Goodwill and Intangible Assets Disclosure [Abstract] | ||
2017 | ||
2018 | ||
2019 | ||
2020 | ||
2021 | ||
Thereafter | ||
Total | 4,055,000 | 5,230,000 |