SECURITIES SOLD UNDER AGREEMENTS TO REPURCHASE (Details) (USD $)	3 Months Ended
	Mar. 31, 2015	Mar. 31, 2014	Dec. 31, 2014
Securities sold under agreements to repurchase
Outstanding balance at end of year	$ 332,534,000		$ 356,108,000
Federal funds purchased	15,000,000
Cost of funds	0.75%
Securities sold under agreements to repurchase
Securities sold under agreements to repurchase
Outstanding balance at end of year	317,534,000		356,108,000
Weighted average interest rate at end of period (as a percent)	0.02%		0.04%
Fair Value of securities pledged	389,421,000		378,478,000
Average outstanding balance during the period	391,254,000	223,079,000
Average interest rate during the period (as a percent)	0.04%	0.04%
Maximum outstanding at any month end during the period	$ 408,955,000	$ 222,174,000