LOANS AND LEASES - Commercial and Consumer Credit Exposure by Risk Attribute (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	$ 1,739,579
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	2,341,158
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,544,333
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	1,152,986
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	846,327
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,309,184
Financing Receivable, before Allowance for Credit Loss	8,933,567
Financing Receivable, Revolving	1,248,144
Loans and Leases Receivable, Net of Deferred Income	10,181,711	$ 9,201,665
Commercial
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,465,877
Commercial \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,324,021
Commercial \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		100,954
Commercial \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		40,902
Commercial \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Construction real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		493,182
Construction real estate \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		493,182
Construction real estate \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Construction real estate \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Construction real estate \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial Real Estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		4,194,651
Commercial Real Estate \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		4,108,752
Commercial Real Estate \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		59,383
Commercial Real Estate \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		26,516
Commercial Real Estate \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Lease financing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		88,364
Lease financing \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		85,262
Lease financing \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		488
Lease financing \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		2,614
Lease financing \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Commercial segment
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		7,242,074
Commercial segment \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		7,011,217
Commercial segment \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		160,825
Commercial segment \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		70,032
Commercial segment \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		0
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,055,949
Residential real estate \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,040,787
Residential real estate \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		15,162
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		771,869
Home equity \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		766,169
Home equity \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		5,700
Installment
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		82,589
Installment \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		82,385
Installment \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		204
Credit card
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		49,184
Credit card \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		48,983
Credit card \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		201
Total consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,959,591
Total consumer \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		1,938,324
Total consumer \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Loans and Leases Receivable, Net of Deferred Income		21,267
Commercial segment
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,161,708
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	537,598
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	460,996
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	312,238
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	178,187
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	178,715
Financing Receivable, before Allowance for Credit Loss	2,829,442
Financing Receivable, Revolving	492,932
Loans and Leases Receivable, Net of Deferred Income	3,322,374	2,465,877
Commercial segment \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	1,150,804
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	529,061
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	439,614
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	272,402
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	165,821
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	171,232
Financing Receivable, before Allowance for Credit Loss	2,728,934
Financing Receivable, Revolving	466,791
Loans and Leases Receivable, Net of Deferred Income	3,195,725
Commercial segment \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,317
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	6,963
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,714
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	14,726
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	4,728
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	5,513
Financing Receivable, before Allowance for Credit Loss	49,961
Financing Receivable, Revolving	19,083
Loans and Leases Receivable, Net of Deferred Income	69,044
Commercial segment \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	3,587
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,574
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	10,668
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	25,110
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,638
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,970
Financing Receivable, before Allowance for Credit Loss	50,547
Financing Receivable, Revolving	7,058
Loans and Leases Receivable, Net of Deferred Income	57,605
Commercial segment \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Lease financing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	8,161
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	31,227
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	16,197
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	10,973
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,450
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,079
Financing Receivable, before Allowance for Credit Loss	80,087
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	80,087	88,364
Lease financing \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	7,803
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	31,227
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	14,775
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	10,114
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	7,097
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	6,079
Financing Receivable, before Allowance for Credit Loss	77,095
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	77,095
Lease financing \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	345
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	356
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	356
Lease financing \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	13
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	1,422
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	848
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	353
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	2,636
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	2,636
Lease financing \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Construction real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	24,877
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	165,903
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	227,147
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	44,944
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,074
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,524
Financing Receivable, before Allowance for Credit Loss	488,469
Financing Receivable, Revolving	17,616
Loans and Leases Receivable, Net of Deferred Income	506,085	493,182
Construction real estate \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	24,877
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	165,278
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	227,147
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	44,944
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	24,074
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	1,524
Financing Receivable, before Allowance for Credit Loss	487,844
Financing Receivable, Revolving	17,616
Loans and Leases Receivable, Net of Deferred Income	505,460
Construction real estate \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	625
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	625
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	625
Construction real estate \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Construction real estate \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Commercial real estate - investor
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	263,928
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,088,708
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	473,912
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	513,051
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	385,191
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	488,806
Financing Receivable, before Allowance for Credit Loss	3,213,596
Financing Receivable, Revolving	37,023
Loans and Leases Receivable, Net of Deferred Income	3,250,619
Commercial real estate - investor \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	256,719
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,084,317
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	455,838
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	493,692
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	367,148
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	462,449
Financing Receivable, before Allowance for Credit Loss	3,120,163
Financing Receivable, Revolving	37,023
Loans and Leases Receivable, Net of Deferred Income	3,157,186
Commercial real estate - investor \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	959
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	57
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	18,637
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	17,948
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	23,819
Financing Receivable, before Allowance for Credit Loss	61,420
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	61,420
Commercial real estate - investor \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	6,250
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	4,334
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	18,074
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	722
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	95
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,538
Financing Receivable, before Allowance for Credit Loss	32,013
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	32,013
Commercial real estate - investor \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Commercial real estate-owner
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	95,701
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	179,889
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	181,979
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	160,208
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	159,747
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	276,114
Financing Receivable, before Allowance for Credit Loss	1,053,638
Financing Receivable, Revolving	39,445
Loans and Leases Receivable, Net of Deferred Income	1,093,083
Commercial real estate-owner \| Pass
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	94,724
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	176,419
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	175,531
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	151,011
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	154,311
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	256,525
Financing Receivable, before Allowance for Credit Loss	1,008,521
Financing Receivable, Revolving	39,180
Loans and Leases Receivable, Net of Deferred Income	1,047,701
Commercial real estate-owner \| Special Mention
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	464
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,890
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,158
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,667
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,937
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	16,833
Financing Receivable, before Allowance for Credit Loss	30,949
Financing Receivable, Revolving	265
Loans and Leases Receivable, Net of Deferred Income	31,214
Commercial real estate-owner \| Substandard
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	513
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	1,580
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	3,290
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	4,530
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	1,499
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	2,756
Financing Receivable, before Allowance for Credit Loss	14,168
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	14,168
Commercial real estate-owner \| Doubtful
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	0
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	0
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	0
Financing Receivable, before Allowance for Credit Loss	0
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	0
Residential real estate
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	140,836
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	293,090
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	147,667
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	85,937
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	76,044
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	300,171
Financing Receivable, before Allowance for Credit Loss	1,043,745
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	1,043,745	1,055,949
Residential real estate \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	140,736
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	292,781
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	147,602
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	85,084
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	75,577
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	295,235
Financing Receivable, before Allowance for Credit Loss	1,037,015
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	1,037,015
Residential real estate \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	100
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	309
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	65
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	853
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	467
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,936
Financing Receivable, before Allowance for Credit Loss	6,730
Financing Receivable, Revolving	0
Loans and Leases Receivable, Net of Deferred Income	6,730
Home equity
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	30,522
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	24,380
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	21,528
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	13,616
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	12,289
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	53,242
Financing Receivable, before Allowance for Credit Loss	155,577
Financing Receivable, Revolving	608,594
Loans and Leases Receivable, Net of Deferred Income	764,171	771,869
Home equity \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	30,522
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	24,380
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	21,470
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	13,577
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	12,289
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	52,983
Financing Receivable, before Allowance for Credit Loss	155,221
Financing Receivable, Revolving	604,913
Loans and Leases Receivable, Net of Deferred Income	760,134
Home equity \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	0
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	0
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	58
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	39
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	0
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	259
Financing Receivable, before Allowance for Credit Loss	356
Financing Receivable, Revolving	3,681
Loans and Leases Receivable, Net of Deferred Income	4,037
Total consumer
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	13,846
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	20,363
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	14,907
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	12,019
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,345
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,533
Financing Receivable, before Allowance for Credit Loss	69,013
Financing Receivable, Revolving	10,137
Loans and Leases Receivable, Net of Deferred Income	79,150	82,589
Total consumer \| Performing
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	13,836
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	20,313
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	14,889
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	11,993
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	3,333
Financing Receivable, Originated, More than Five Years before Current Fiscal Year	4,492
Financing Receivable, before Allowance for Credit Loss	68,856
Financing Receivable, Revolving	10,137
Loans and Leases Receivable, Net of Deferred Income	78,993
Total consumer \| Nonperforming
Financing Receivable, Credit Quality Indicator [Line Items]
Financing Receivable, Year One, Originated, Current Fiscal Year	10
Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year	50
Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year	18
Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year	26
Financing Receivable, Year Five, Originated, Four Years before Current Fiscal Year	12

LOANS AND LEASES - Commercial and Consumer Credit Exposure by Risk Attribute (Details) - USD ($)
$ in Thousands

Jun. 30, 2020

Dec. 31, 2019

Financing Receivable, Credit Quality Indicator [Line Items]

Financing Receivable, Year One, Originated, Current Fiscal Year

$ 1,739,579

Financing Receivable, Year Two, Originated, Fiscal Year before Current Fiscal Year

2,341,158

Financing Receivable, Year Three, Originated, Two Years before Current Fiscal Year

1,544,333

Financing Receivable, Year Four, Originated, Three Years before Current Fiscal Year

1,152,986