OTHER COMPREHENSIVE INCOME - AOCI Changes (Details) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2020	Mar. 31, 2019
Summary of the AOCI balances, net of tax
Balance at beginning of period	$ 764,244	$ 689,934
Current Year Change	5,733	2,794
Balance at end of period	784,046	717,091
Accumulated Other Comprehensive Income
Summary of the AOCI balances, net of tax
Balance at beginning of period	3,098	(997)
Current Year Change	5,733	2,794
Balance at end of period	8,831	1,797
Unrealized gain (loss) on AFS debt securities
Summary of the AOCI balances, net of tax
Balance at beginning of period	2,211	(2,165)
Current Year Change	5,832	2,891
Balance at end of period	8,043	726
Unrealized gain (loss) on AFS debt security for which a portion of OTTI has been recognized in earnings
Summary of the AOCI balances, net of tax
Balance at beginning of period	964	1,078
Current Year Change	1	(27)
Balance at end of period	965	1,051
Unrealized gain (loss) on cash flow hedges
Summary of the AOCI balances, net of tax
Balance at beginning of period	(77)	90
Current Year Change	(100)	(70)
Balance at end of period	$ (177)	$ 20