OFF BALANCE SHEET RISKS, COMMITMENTS AND CONTINGENT LIABILITIES (Details) - USD ($) $ in Thousands	Jun. 30, 2017	Dec. 31, 2016
Commitments and letters of credit
Loan commitment, line credit	$ 1,528,720	$ 1,373,917
Unused warehouse lines of credit
Commitments and letters of credit
Loan commitment, line credit	474,370	453,110
Unused home equity lines of credit
Commitments and letters of credit
Loan commitment, line credit	357,497	341,434
Unused loan commitments - other
Commitments and letters of credit
Loan commitment, line credit	683,199	560,629
Commitments to purchase loans
Commitments and letters of credit
Loan commitment, line credit	1,154	3,176
Standby letters of credit
Commitments and letters of credit
Loan commitment, line credit	$ 12,500	$ 15,568