COMMITMENTS AND CONTINGENCIES (Details) - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Lending commitments:
Commitments to extend credit	$ 1,468,090	$ 799,058
Commercial letters of credit	22,108	16,342
Other commitments:
Standby letters of credit issued by the FHLB on the Bank's behalf	46,000	10,000
Reserve for unfunded commitments	$ 1,257	$ 603