LOANS AND ALLOWANCE FOR LOAN LOSSES (Narrative) (Details) - USD ($) $ in Thousands |
9 Months Ended | ||
|---|---|---|---|
Sep. 30, 2018 |
Sep. 30, 2017 |
Dec. 31, 2017 |
|
| Financing Receivable, Modifications [Line Items] | |||
| Period for restructured loan to be considered default | 90 days | ||
| Provision for loan losses | $ (9,103) | $ (7,360) | |
| Total loans held for investment, net | 9,411,598 | $ 7,141,552 | |
| Acquired Performing Loan Portfolio | |||
| Financing Receivable, Modifications [Line Items] | |||
| Total loans held for investment, net | 2,200,000 | 892,400 | |
| Remaining discount on acquired loans | 33,400 | 13,700 | |
| Purchased Impaired | |||
| Financing Receivable, Modifications [Line Items] | |||
| Total loans held for investment, net | 94,746 | 39,021 | |
| Purchased impaired loans (gross) | $ 119,100 | $ 47,900 | |