REGULATORY CAPITAL REQUIREMENTS (Details) - USD ($) $ in Thousands	Dec. 31, 2019	Dec. 31, 2018
Company (consolidated) [Member]
Total capital (to risk weighted assets):
Actual	$ 1,352,341	$ 992,454
Actual Ratio	14.83%	14.45%
Capital Required for Capital Adequacy	$ 729,291	$ 549,297
For Capital Adequacy Purposes Ratio	8.00%	8.00%
Common Equity Tier One Capital	$ 1,171,963	$ 818,176
Common Equity tier One Capital to Risk Weighted Assets	12.86%	11.92%
Common Equity Tier One Capital Required for Capital Adequacy	$ 410,226	$ 308,980
Common Equity Tier One Capital for Capitalized Adequacy to Risk Weighted Assets	4.50%	4.50%
Tier 1 capital (to risk weighted assets):
Actual	$ 1,232,963	$ 892,176
Actual Ratio	13.53%	12.99%
For Capital Adequacy Purposes	$ 546,969	$ 411,973
For Capital Adequacy Purposes Ratio	6.00%	6.00%
Tier 1 capital (to average assets):
Actual	$ 1,232,963	$ 892,176
Actual Ratio	11.28%	10.69%
For Capital Adequacy Purposes	$ 437,271	$ 333,754
For Capital Adequacy Purposes Ratio	4.00%	4.00%
Bank [Member]
Total capital (to risk weighted assets):
Actual	$ 1,275,611	$ 937,574
Actual Ratio	14.00%	13.66%
Capital Required for Capital Adequacy	$ 728,868	$ 549,036
For Capital Adequacy Purposes Ratio	8.00%	8.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 911,085	$ 686,295
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	10.00%	10.00%
Common Equity Tier One Capital	$ 1,205,740	$ 872,024
Common Equity tier One Capital to Risk Weighted Assets	13.23%	12.71%
Common Equity Tier One Capital Required for Capital Adequacy	$ 409,988	$ 308,833
Common Equity Tier One Capital for Capitalized Adequacy to Risk Weighted Assets	4.50%	4.50%
Common Equity Tier 1 Capital to be Well Capitalized	$ 592,205	$ 446,092
Common Equity Tier One Capital to be Well Capitalized to Risk Weighted Assets	6.50%	6.50%
Tier 1 capital (to risk weighted assets):
Actual	$ 1,205,740	$ 872,024
Actual Ratio	13.23%	12.71%
For Capital Adequacy Purposes	$ 546,651	$ 411,777
For Capital Adequacy Purposes Ratio	6.00%	6.00%
To Be Well Capitalized Under Prompt Corrective Action Provisions	$ 728,868	$ 549,036
To Be Well Capitalized Under Prompt Corrective Action Provisions Ratio	8.00%	8.00%
Tier 1 capital (to average assets):
Actual	$ 1,205,740	$ 872,024
Actual Ratio	11.06%	10.46%
For Capital Adequacy Purposes	$ 435,886	$ 333,595
For Capital Adequacy Purposes Ratio	4.00%	4.00%
To Be Well Capitalized Under Prompt Correction Action Provisions	$ 544,857	$ 416,994
To Be Well Capitalized Under Prompt Correction Action Provisions Ratio	5.00%	5.00%

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