LOANS AND LEASES - Loan Delinquency, including Nonaccrual Loans (Details) - USD ($) $ in Thousands	Jun. 30, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 48,753	$ 48,554
Current	10,132,958	9,084,447
Loans and Leases Receivable, Gross		9,133,001
Purchased impaired loans		68,664
Total loans and leases	10,181,711	9,201,665
> 90 days past due and still accruing	124	201
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4,879	12,923
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	16,603	7,325
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	27,271	28,306
Commercial
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	14,241	19,116
Current	3,308,133	2,443,680
Loans and Leases Receivable, Gross		2,462,796
Purchased impaired loans		3,081
Total loans and leases	3,322,374	2,465,877
> 90 days past due and still accruing	0	0
Commercial | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	474	1,266
Commercial | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	194	3,332
Commercial | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	13,573	14,518
Lease financing
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Current	80,087	88,364
Loans and Leases Receivable, Gross		88,364
Purchased impaired loans		0
Total loans and leases	80,087	88,364
> 90 days past due and still accruing	0	0
Lease financing | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Lease financing | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Lease financing | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Construction real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Current	506,085	493,167
Loans and Leases Receivable, Gross		493,167
Purchased impaired loans		15
Total loans and leases	506,085	493,182
> 90 days past due and still accruing	0	0
Construction real estate | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Construction real estate | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Construction real estate | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Commercial real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due		7,246
Current		4,151,513
Loans and Leases Receivable, Gross		4,158,759
Purchased impaired loans		35,892
Total loans and leases	4,343,702	4,194,651
> 90 days past due and still accruing		0
Commercial real estate | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due		776
Commercial real estate | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due		857
Commercial real estate | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due		5,613
Commercial real estate - investor
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	19,569
Current	3,231,050
Total loans and leases	3,250,619
> 90 days past due and still accruing	0
Commercial real estate - investor | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	119
Commercial real estate - investor | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	13,790
Commercial real estate - investor | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	5,660
Commercial real estate-owner
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	3,626
Current	1,089,457
Total loans and leases	1,093,083
> 90 days past due and still accruing	0
Commercial real estate-owner | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,663
Commercial real estate-owner | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	110
Commercial real estate-owner | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,853
Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	6,731	14,991
Current	1,037,014	1,014,138
Loans and Leases Receivable, Gross		1,029,129
Purchased impaired loans		26,820
Total loans and leases	1,043,745	1,055,949
> 90 days past due and still accruing	0	0
Residential real estate | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,790	8,032
Residential real estate | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	1,421	1,928
Residential real estate | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	3,520	5,031
Home equity
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4,036	6,408
Current	760,135	762,863
Loans and Leases Receivable, Gross		769,271
Purchased impaired loans		2,598
Total loans and leases	764,171	771,869
> 90 days past due and still accruing	0	0
Home equity | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	596	2,530
Home equity | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	969	1,083
Home equity | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,471	2,795
Installment
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	155	309
Current	78,995	82,022
Loans and Leases Receivable, Gross		82,331
Purchased impaired loans		258
Total loans and leases	79,150	82,589
> 90 days past due and still accruing	0	0
Installment | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	46	111
Installment | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	40	50
Installment | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	69	148
Credit card
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	395	484
Current	42,002	48,700
Loans and Leases Receivable, Gross		49,184
Purchased impaired loans		0
Total loans and leases	42,397	49,184
> 90 days past due and still accruing	124	201
Credit card | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	191	208
Credit card | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	79	75
Credit card | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 125	$ 201