LOANS - Categorized by Internally Assigned Risk Grades (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Loans by class categorized by internally assigned risk grades
Total loans	$ 4,605,583	$ 3,672,596
2020	1,478,560
2019	778,152
2018	344,823
2017	536,632
2016	298,865
2015 and prior	708,640
Revolving	436,376
Revolving Term	23,535
Total	4,605,583
Pass
Loans by class categorized by internally assigned risk grades
Total loans		3,584,290
Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		47,003
Substandard
Loans by class categorized by internally assigned risk grades
Total loans		41,303
Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Commercial Real Estate | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans		1,565,687
Commercial Real Estate | Mortgage loans | Owner occupied
Loans by class categorized by internally assigned risk grades
Total loans	557,076	531,088
2020	95,092
2019	98,605
2018	59,137
2017	87,914
2016	32,526
2015 and prior	183,802
Total	557,076
Commercial Real Estate | Mortgage loans | Owner occupied | Pass
Loans by class categorized by internally assigned risk grades
Total loans		511,444
2020	92,053
2019	96,679
2018	47,224
2017	66,320
2016	25,852
2015 and prior	153,766
Total	481,894
Commercial Real Estate | Mortgage loans | Owner occupied | Watch
Loans by class categorized by internally assigned risk grades
2020	727
2019	1,373
2018	8,038
2017	10,737
2016	3,425
2015 and prior	23,919
Total	48,219
Commercial Real Estate | Mortgage loans | Owner occupied | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		18,426
2020	1,843
2018	3,875
2017	10,857
2016	823
2015 and prior	4,600
Total	21,998
Commercial Real Estate | Mortgage loans | Owner occupied | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		1,218
2020	469
2019	553
2016	2,426
2015 and prior	1,517
Total	4,965
Commercial Real Estate | Mortgage loans | Owner occupied | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Commercial Real Estate | Mortgage loans | Non-owner occupied
Loans by class categorized by internally assigned risk grades
Total loans	1,081,443	1,034,599
2020	189,125
2019	257,482
2018	120,931
2017	201,358
2016	72,499
2015 and prior	240,048
Total	1,081,443
Commercial Real Estate | Mortgage loans | Non-owner occupied | Pass
Loans by class categorized by internally assigned risk grades
Total loans		1,022,208
2020	181,811
2019	249,782
2018	108,086
2017	180,235
2016	54,252
2015 and prior	214,620
Total	988,786
Commercial Real Estate | Mortgage loans | Non-owner occupied | Watch
Loans by class categorized by internally assigned risk grades
2020	7,314
2019	7,700
2018	12,845
2017	12,117
2016	12,209
2015 and prior	24,089
Total	76,274
Commercial Real Estate | Mortgage loans | Non-owner occupied | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		0
2015 and prior	290
Total	290
Commercial Real Estate | Mortgage loans | Non-owner occupied | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		12,391
2017	9,006
2016	6,038
2015 and prior	1,049
Total	16,093
Commercial Real Estate | Mortgage loans | Non-owner occupied | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Multi-family
Loans by class categorized by internally assigned risk grades
Total loans		812,174
2020	174,737
2019	296,476
2018	40,840
2017	113,598
2016	154,822
2015 and prior	119,257
Total	899,730
Multi-family | Pass
Loans by class categorized by internally assigned risk grades
2020	159,301
2019	293,752
2018	40,840
2017	86,169
2016	118,846
2015 and prior	106,044
Total	804,952
Multi-family | Watch
Loans by class categorized by internally assigned risk grades
2020	15,436
2019	2,724
2017	19,331
2016	35,976
2015 and prior	12,825
Total	86,292
Multi-family | Special Mention
Loans by class categorized by internally assigned risk grades
2017	8,098
2015 and prior	388
Total	8,486
Multi-family | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans	899,730	812,174
Multi-family | Mortgage loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans		811,770
Multi-family | Mortgage loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		404
Multi-family | Mortgage loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		0
Multi-family | Mortgage loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Residential Real Estate Loans
Loans by class categorized by internally assigned risk grades
Total loans	434,689	493,144
2020	20,033
2019	34,133
2018	73,636
2017	96,970
2016	24,130
2015 and prior	122,104
Revolving	54,035
Revolving Term	9,648
Total	434,689
Residential Real Estate Loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans		475,949
2020	20,033
2019	32,564
2018	71,903
2017	95,712
2016	23,589
2015 and prior	106,518
Revolving	53,217
Revolving Term	7,012
Total	410,548
Residential Real Estate Loans | Watch
Loans by class categorized by internally assigned risk grades
2018	406
2017	321
2016	541
2015 and prior	1,740
Revolving Term	1,145
Total	4,153
Residential Real Estate Loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		12,400
2019	1,103
2018	758
2015 and prior	6,879
Revolving	818
Revolving Term	633
Total	10,191
Residential Real Estate Loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		4,795
2019	466
2018	569
2017	937
2015 and prior	6,967
Revolving Term	858
Total	9,797
Residential Real Estate Loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Residential Real Estate Loans | Mortgage loans
Loans by class categorized by internally assigned risk grades
Total loans	434,689	493,144
Commercial, industrial and agricultural:
Loans by class categorized by internally assigned risk grades
Total loans	1,527,147	679,444
2020	960,233
2019	70,293
2018	40,806
2017	24,241
2016	14,888
2015 and prior	40,637
Revolving	364,413
Revolving Term	11,636
Total	1,527,147
Commercial, industrial and agricultural: | Pass
Loans by class categorized by internally assigned risk grades
Total loans		643,413
2020	949,257
2019	62,410
2018	30,736
2017	17,646
2016	12,685
2015 and prior	26,606
Revolving	304,781
Revolving Term	5,086
Total	1,409,207
Commercial, industrial and agricultural: | Watch
Loans by class categorized by internally assigned risk grades
2020	8,062
2019	6,140
2018	8,265
2017	1,574
2016	1,188
2015 and prior	3,048
Revolving	40,448
Revolving Term	1,527
Total	70,252
Commercial, industrial and agricultural: | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		15,670
2020	2,914
2019	838
2018	572
2017	1,507
2016	545
2015 and prior	1,323
Revolving	18,984
Revolving Term	2,073
Total	28,756
Commercial, industrial and agricultural: | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		20,361
2019	905
2018	1,233
2017	3,514
2016	470
2015 and prior	9,660
Revolving	200
Revolving Term	2,950
Total	18,932
Commercial, industrial and agricultural: | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Real estate construction and land loans
Loans by class categorized by internally assigned risk grades
Total loans	82,479	97,311
2020	37,684
2019	20,948
2018	9,307
2017	12,458
2015 and prior	2,082
Total	82,479
Real estate construction and land loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans		95,530
2020	37,684
2019	20,948
2018	8,229
2017	11,308
2015 and prior	1,701
Total	79,870
Real estate construction and land loans | Watch
Loans by class categorized by internally assigned risk grades
2017	1,150
2015 and prior	270
Total	1,420
Real estate construction and land loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		0
2018	1,078
Total	1,078
Real estate construction and land loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		1,781
2015 and prior	111
Total	111
Real estate construction and land loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		0
Installment/consumer loans
Loans by class categorized by internally assigned risk grades
Total loans	23,019	24,836
2020	1,656
2019	215
2018	166
2017	93
2015 and prior	710
Revolving	17,928
Revolving Term	2,251
Total	23,019
Installment/consumer loans | Pass
Loans by class categorized by internally assigned risk grades
Total loans		23,976
2020	1,656
2019	215
2018	166
2017	93
2015 and prior	710
Revolving	17,382
Revolving Term	1,257
Total	21,479
Installment/consumer loans | Watch
Loans by class categorized by internally assigned risk grades
Revolving	496
Revolving Term	40
Total	536
Installment/consumer loans | Special Mention
Loans by class categorized by internally assigned risk grades
Total loans		103
Revolving Term	46
Total	46
Installment/consumer loans | Substandard
Loans by class categorized by internally assigned risk grades
Total loans		757
Revolving	50
Revolving Term	908
Total	$ 958
Installment/consumer loans | Doubtful
Loans by class categorized by internally assigned risk grades
Total loans		$ 0