OTHER COMPREHENSIVE INCOME - AOCI Changes (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Summary of the AOCI balances, net of tax
Balance at beginning of period			$ 604,406
Current Year Change	$ (57)	$ (341)	808	$ 925
Balance at end of period	633,287		633,287
Accumulated Other Comprehensive Income
Summary of the AOCI balances, net of tax
Balance at beginning of period			687	2,049
Current Year Change			808	925
Balance at end of period	1,495	2,974	1,495	2,974
Unrealized gain on securities available for sale
Summary of the AOCI balances, net of tax
Balance at beginning of period			237	1,727
Current Year Change			579	1,247
Balance at end of period	816	2,974	816	2,974
Unrealized gain on security available for sale for which a portion of an other-than-temporary impairment has been recognized in earnings
Summary of the AOCI balances, net of tax
Balance at beginning of period			706	712
Current Year Change			158	(58)
Balance at end of period	864	654	864	654
Unrealized loss on cash flow hedge
Summary of the AOCI balances, net of tax
Balance at beginning of period			(256)	(390)
Current Year Change			71	(264)
Balance at end of period	$ (185)	$ (654)	$ (185)	$ (654)