MORTGAGE BANKING ACTIVITIES - COMPONENTS OF INCOME (Details) - USD ($)
$ in Thousands
12 Months Ended
Dec. 31, 2016
Dec. 31, 2015
Dec. 31, 2014
Mortgage servicing rights      
Net gain realized on sale of mortgage loans held for sale $ 5,478 $ 3,882 $ 2,278
Net gain realized on sale of mortgage loans transferred from held for investment to held for sale 1,129    
Net gain recognized 6,656 3,915 2,440
Loan servicing income 1,983 1,896 1,752
Amortization of mortgage servicing rights (1,757) (1,400) (1,330)
Net servicing income recognized 226 496 422
Total Mortgage Banking income 6,882 4,411 2,862
Mortgage loans held for sale      
Mortgage servicing rights      
Net change in fair value 4 (33) 34
Rate lock loan commitments      
Mortgage servicing rights      
Net change in fair value (8) 57 173
Mandatory forward contracts      
Mortgage servicing rights      
Net change in fair value $ 53 $ 9 $ (45)