OFF BALANCE SHEET RISKS, COMMITMENTS AND CONTINGENT LIABILITIES (Details) - USD ($) $ in Thousands	Mar. 31, 2017	Mar. 31, 2016
Commitments and letters of credit
Loan commitment, line credit	$ 1,494,412	$ 1,373,917
Unused warehouse lines of credit
Commitments and letters of credit
Loan commitment, line credit	499,100	453,110
Unused home equity lines of credit
Commitments and letters of credit
Loan commitment, line credit	353,974	341,434
Unused loan commitments - other
Commitments and letters of credit
Loan commitment, line credit	635,659	560,629
Commitments to purchase loans
Commitments and letters of credit
Loan commitment, line credit		3,176
Standby letters of credit
Commitments and letters of credit
Loan commitment, line credit	$ 5,679	$ 15,568