OFF BALANCE SHEET RISKS, COMMITMENTS AND CONTINGENT LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Commitments and letters of credit
Loan commitment, line credit	$ 1,373,917	$ 950,948
Unused warehouse lines of credit
Commitments and letters of credit
Loan commitment, line credit	453,110	304,379
Unused home equity lines of credit
Commitments and letters of credit
Loan commitment, line credit	341,434	282,007
Unused loan commitments - other
Commitments and letters of credit
Loan commitment, line credit	560,629	329,232
Commitments to purchase loans
Commitments and letters of credit
Loan commitment, line credit	3,176	22,590
Standby letters of credit
Commitments and letters of credit
Loan commitment, line credit	$ 15,568	$ 12,740