SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Securities sold under agreements to repurchase
Securities pledged more than repurchase agreements (as a percent)	2.00%
Outstanding balance at end of year	$ 395,433	$ 356,108
Weighted average interest rate at end of period (as a percent)	0.02%	0.04%
Fair Value of securities pledged	$ 458,194	$ 378,478
Average outstanding balance during the period	$ 379,477	$ 296,196	$ 170,386
Average interest rate during the period (as a percent)	0.02%	0.04%	0.04%
Maximum outstanding at any month end during the period	$ 442,981	$ 408,891	$ 242,721
U.S. Treasury securities and U.S. Government agencies
Securities sold under agreements to repurchase
Fair Value of securities pledged	244,707	121,378
Mortgage backed securities - residential
Securities sold under agreements to repurchase
Fair Value of securities pledged	82,666	105,144
Collateralized mortgage obligations
Securities sold under agreements to repurchase
Fair Value of securities pledged	$ 130,821	$ 151,956