INCOME TAXES - Current and deferred amounts of income tax expense (Details) - USD ($) $ in Thousands |
12 Months Ended | ||
|---|---|---|---|
Dec. 31, 2016 |
Dec. 31, 2015 |
Dec. 31, 2014 |
|
| Income Tax Disclosure [Abstract] | |||
| Current | $ 6,033 | $ 5,486 | $ 4,675 |
| Deferred | 3,338 | 603 | (68) |
| Income tax expense | $ 9,371 | $ 6,089 | $ 4,607 |