ACCUMULATED OTHER COMPREHENSIVE INCOME (LOSS) - Reclassifications out of AOCI(L) (Details) - USD ($) $ in Thousands	3 Months Ended								12 Months Ended
	Dec. 31, 2015	Sep. 30, 2015	Jun. 30, 2015	Mar. 31, 2015	Dec. 31, 2014	Sep. 30, 2014	Jun. 30, 2014	Mar. 31, 2014	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013
Accumulated Other Comprehensive Income (Loss) [Line Items]
Salaries and employee benefits									$ (17,023)	$ (17,273)	$ (15,415)
Income tax provision	$ (1,106)	$ (957)	$ (825)	$ (848)	$ (652)	$ (1,576)	$ (875)	$ (701)	(3,736)	(3,804)	$ (3,451)
Amount Reclassified from Accumulated Other Comprehensive Income | Net Unrealized Gain (Loss) on Available for Sale Securities
Accumulated Other Comprehensive Income (Loss) [Line Items]
Securities gains, net									(2,592)	(3,515)
Income tax provision									882	1,195
Net of tax									(1,710)	(2,320)
Amount Reclassified from Accumulated Other Comprehensive Income | Defined Benefit Plan
Accumulated Other Comprehensive Income (Loss) [Line Items]
Salaries and employee benefits									159	209
Income tax provision									(54)	(71)
Net of tax									$ 105	$ 138