REGULATORY CAPITAL (Schedule of Regulatory Capital Amounts and Ratios) (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
The Bank [Member]
Total Capital
Total Capital (to risk-weighted assets)	$ 571,509	$ 543,008
Total Capital (to risk-weighted assets) ratio	13.76%	14.59%
Minimum Capital required to be well-capitalized	$ 415,487	$ 372,186
Minimum Capital required to be well-capitalized, ratio	10.00%	10.00%
Minimum amount of capital for adequacy purposes	$ 332,389	$ 297,749
Minimum amount of capital for adequacy purposes, ratio	8.00%	8.00%
Tier I Capital (to risk-weighted assets)
Tier 1 Capital (to risk-weighted assets)	$ 527,833	$ 504,504
Tier 1 Capital (to risk-weighted assets) ratio	12.70%	13.56%
Minimum Tier 1 Capital required to be well-capitalized	$ 332,389	$ 297,749
Minimum Tier 1 Capital required to be well-capitalized, ratio	8.00%	8.00%
Minimum amount of Tier 1 Capital for adequacy purposes	$ 249,292	$ 223,311
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	6.00%	6.00%
Common equity tier I
Common equity tier 1 (to risk-weighted assets)	$ 527,832	$ 504,502
Common equity tier I (to risk-weighted assets) ratio	12.70%	13.56%
Minimum Common equity tier I required to be well-capitalized	$ 270,066	$ 241,921
Minimum common equity tier I required to be well-capitalized, ratio	6.50%	6.50%
Minimum amount of common equity tier I for adequacy purposes	$ 186,969	$ 167,484
Minimum amount of common equity tier I for adequacy purposes, ratio	4.50%	4.50%
Tier I Leverage Capital (to average assets)
Tier 1 Capital(to average assets)	$ 527,833	$ 504,504
Tier 1 Capital (to average assets) ratio	10.63%	11.32%
Minimum Tier 1 Capital required to be well-capitalized	$ 248,252	$ 222,912
Minimum Tier 1 Capital required to be well-capitalized, ratio	5.00%	5.00%
Minimum amount of Tier 1 Capital for adequacy purposes	$ 198,602	$ 178,330
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	4.00%	4.00%
The Bank [Member] \| Conservation Buffer [Member]
Total Capital
Minimum amount of capital for adequacy purposes	$ 436,261	$ 367,533
Minimum amount of capital for adequacy purposes, ratio	10.50%	9.88%
Tier I Capital (to risk-weighted assets)
Minimum amount of Tier 1 Capital for adequacy purposes	$ 353,164	$ 293,096
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	8.50%	7.88%
Common equity tier I
Minimum amount of common equity tier I for adequacy purposes	$ 290,841	$ 237,268
Minimum amount of common equity tier I for adequacy purposes, ratio	7.00%	6.38%
Tier I Leverage Capital (to average assets)
Minimum amount of Tier 1 Capital for adequacy purposes	$ 198,602	$ 178,330
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	4.00%	4.00%
Parent Company [Member]
Total Capital
Total Capital (to risk-weighted assets)	$ 590,614	$ 559,937
Total Capital (to risk-weighted assets) ratio	14.20%	15.03%
Minimum amount of capital for adequacy purposes	$ 332,783	$ 298,047
Minimum amount of capital for adequacy purposes, ratio	8.00%	8.00%
Tier I Capital (to risk-weighted assets)
Tier 1 Capital (to risk-weighted assets)	$ 463,521	$ 438,240
Tier 1 Capital (to risk-weighted assets) ratio	11.14%	11.76%
Minimum amount of Tier 1 Capital for adequacy purposes	$ 249,587	$ 223,535
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	6.00%	6.00%
Common equity tier I
Common equity tier 1 (to risk-weighted assets)	$ 463,520	$ 438,238
Common equity tier I (to risk-weighted assets) ratio	11.14%	11.76%
Minimum amount of common equity tier I for adequacy purposes	$ 187,190	$ 167,652
Minimum amount of common equity tier I for adequacy purposes, ratio	4.50%	4.50%
Tier I Leverage Capital (to average assets)
Tier 1 Capital(to average assets)	$ 463,521	$ 438,240
Tier 1 Capital (to average assets) ratio	9.33%	9.82%
Minimum amount of Tier 1 Capital for adequacy purposes	$ 198,792	$ 178,473
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	4.00%	4.00%
Parent Company [Member] \| Conservation Buffer [Member]
Total Capital
Minimum amount of capital for adequacy purposes	$ 436,778	$ 367,902
Minimum amount of capital for adequacy purposes, ratio	10.50%	9.88%
Tier I Capital (to risk-weighted assets)
Minimum amount of Tier 1 Capital for adequacy purposes	$ 353,582	$ 293,390
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	8.50%	7.88%
Common equity tier I
Minimum amount of common equity tier I for adequacy purposes	$ 291,185	$ 237,506
Minimum amount of common equity tier I for adequacy purposes, ratio	7.00%	6.38%
Tier I Leverage Capital (to average assets)
Minimum amount of Tier 1 Capital for adequacy purposes	$ 198,792	$ 178,473
Minimum amount of Tier 1 Capital for adequacy purposes, ratio	4.00%	4.00%

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