FAIR VALUE MEASUREMENTS - Fair Values of Financial Instruments Measured on Nonrecurring Basis (Details 1) - Nonrecurring basis - USD ($) $ in Thousands |
Mar. 31, 2019 |
Dec. 31, 2018 |
Dec. 31, 2017 |
|---|---|---|---|
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
| Impaired loans | $ 4,476 | $ 659 | $ 3,670 |
| Other real estate owned | 1,720 | 1,676 | |
| Quoted Prices in Active Markets for Identical Assets Level 1 | |||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
| Impaired loans | 0 | 0 | 0 |
| Other real estate owned | 0 | 0 | |
| Significant Other Observable Inputs Level 2 | |||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
| Impaired loans | 0 | 0 | 0 |
| Other real estate owned | 1,720 | 1,676 | |
| Significant Unobservable Inputs Level 3 | |||
| Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items] | |||
| Impaired loans | 4,476 | 659 | $ 3,670 |
| Other real estate owned | $ 0 | $ 0 |