INCOME TAXES - Components of income tax expense (Details) - USD ($) $ in Thousands |
3 Months Ended | 12 Months Ended | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|
Mar. 31, 2019 |
Dec. 31, 2018 |
Sep. 30, 2018 |
Jun. 30, 2018 |
Mar. 31, 2018 |
Dec. 31, 2017 |
Sep. 30, 2017 |
Jun. 30, 2017 |
Mar. 31, 2017 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|
| Current tax expense (benefit): | |||||||||||
| Federal | $ 3,214 | $ 5,044 | |||||||||
| State | 1,278 | 1,079 | |||||||||
| Net operating loss carryforward | (14) | (14) | |||||||||
| Current tax expense (benefit), total | 4,478 | 6,109 | |||||||||
| Deferred tax expense (benefit): | |||||||||||
| Federal | (926) | 1,523 | |||||||||
| State | (315) | (214) | |||||||||
| Deferred tax expense (benefit), total | $ (185) | (1,241) | 1,309 | ||||||||
| Income tax expense | $ 778 | $ 975 | $ 741 | $ 843 | $ 678 | $ 4,498 | $ 1,434 | $ 639 | $ 847 | $ 3,237 | $ 7,418 |