CAPITAL REQUIREMENTS AND RESTRICTIONS ON RETAINED EARNINGS - Summary Of Capital Adequacy Requirements (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Consolidated Entities [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations
Total Capital (to Risk Weighted Assets), Actual Amount	$ 631,723	$ 601,379
Total Capital (to Risk Weighted Assets), Actual Ratio	14.36%	14.20%
Tier I Capital (to Risk Weighted Assets), Actual Amount	$ 580,982	$ 552,836
Tier I Capital (to Risk Weighted Assets), Actual Ratio	13.21%	13.06%
Common Equity Tier 1 (CET1), Actual Amount	$ 580,982	$ 522,836
Common Equity Tier 1 (CET1), Actual Ratio	13.21%	12.35%
Tier I Capital (to Average Assets), Actual Amount	$ 580,982	$ 552,836
Tier I Capital (to Average Assets), Actual Ratio	11.67%	11.44%
Total Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 351,894	$ 338,690
Total Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier I Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 263,921	$ 254,017
Tier I Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Ratio	6.00%	6.00%
Common Equity Tier 1 (CET1), Minimum Required For Capital Adequacy Purposes Amount	$ 197,941	$ 190,513
Common Equity Tier 1 (CET1), Minimum Required For Capital Adequacy Purposes Ratio	4.50%	4.50%
Tier I Capital (to Average Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 199,099	$ 193,305
Tier I Capital (to Average Assets), Minimum Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Excess Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 461,862	$ 418,070
Tier I Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	373,887	333,398
Common Equity Tier 1 (CET1), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	307,908	269,893
Tier I Capital (to Average Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	199,099	193,305
Bank [Member]
Compliance with Regulatory Capital Requirements under Banking Regulations
Total Capital (to Risk Weighted Assets), Actual Amount	$ 616,386	$ 583,206
Total Capital (to Risk Weighted Assets), Actual Ratio	14.04%	13.80%
Tier I Capital (to Risk Weighted Assets), Actual Amount	$ 565,645	$ 534,664
Tier I Capital (to Risk Weighted Assets), Actual Ratio	12.88%	12.65%
Common Equity Tier 1 (CET1), Actual Amount	$ 565,645	$ 534,664
Common Equity Tier 1 (CET1), Actual Ratio	12.88%	12.65%
Tier I Capital (to Average Assets), Actual Amount	$ 565,645	$ 534,664
Tier I Capital (to Average Assets), Actual Ratio	11.43%	11.06%
Total Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 351,227	$ 338,098
Total Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Ratio	8.00%	8.00%
Tier I Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 263,420	$ 253,574
Tier I Capital (to Risk Weighted Assets), Minimum Required For Capital Adequacy Purposes Ratio	6.00%	6.00%
Common Equity Tier 1 (CET1), Minimum Required For Capital Adequacy Purposes Amount	$ 197,565	$ 190,180
Common Equity Tier 1 (CET1), Minimum Required For Capital Adequacy Purposes Ratio	4.50%	4.50%
Tier I Capital (to Average Assets), Minimum Required For Capital Adequacy Purposes Amount	$ 197,923	$ 193,312
Tier I Capital (to Average Assets), Minimum Required For Capital Adequacy Purposes Ratio	4.00%	4.00%
Excess Capital, For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 460,985	$ 417,340
Excess Capital to Risk Weighted Assets, For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	10.50%	9.875%
Tier I Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 373,179	$ 332,815
Tier I Capital (to Risk Weighted Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	8.50%	7.875%
Common Equity Tier 1 (CET1), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 307,324	$ 269,422
Common Equity Tier 1 (CET1), For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	7.00%	6.375%
Tier I Capital (to Average Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Amount	$ 197,923	$ 193,312
Tier I Capital (to Average Assets), For Capital Adequacy Purposes Plus Capital Conservation Buffer Ratio	4.00%	4.00%
Total Capital (to Risk Weighted Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Amount	$ 439,034	$ 422,623
Total Capital (to Risk Weighted Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	10.00%	10.00%
Tier I Capital (to Risk Weighted Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Amount	$ 351,227	$ 338,098
Tier I Capital (to Risk Weighted Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	8.00%	8.00%
Common Equity Tier 1 (CET1), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Amount	$ 285,372	$ 274,705
Common Equity Tier 1 (CET1), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	6.50%	6.50%
Tier I Capital (to Average Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Amount	$ 247,404	$ 241,639
Tier I Capital (to Average Assets), Minimum Required to Be Well Capitalized Under Prompt Corrective Action Regulations Ratio	5.00%	5.00%