SECURITIES (Debt Securities, Held-to-Maturity, Credit Rating) (Details) - USD ($) $ in Thousands	Jun. 30, 2021	Dec. 31, 2020
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	$ 455,366	$ 421,807
U.S. Government and agency obligations
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	318	340
Municipal bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	395,683	370,998
Corporate bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	3,157	3,222
Mortgage-backed or related securities
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	56,208	47,247
Standard & Poor's, AAA to A Rating
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	362,417	349,623
Standard & Poor's, AAA to A Rating | U.S. Government and agency obligations
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0	0
Standard & Poor's, AAA to A Rating | Municipal bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	361,917	349,123
Standard & Poor's, AAA to A Rating | Corporate bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	500	500
Standard & Poor's, AAA to A Rating | Mortgage-backed or related securities
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	0	0
Standard & Poor's, Not Rated
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	92,949	72,184
Standard & Poor's, Not Rated | U.S. Government and agency obligations
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	318	340
Standard & Poor's, Not Rated | Municipal bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	33,766	21,875
Standard & Poor's, Not Rated | Corporate bonds
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	2,657	2,722
Standard & Poor's, Not Rated | Mortgage-backed or related securities
Financing Receivable, Credit Quality Indicator [Line Items]
Debt securities, held-to-maturity	$ 56,208	$ 47,247