LOANS AND LEASES - Loan Delinquency, including Nonaccrual Loans (Details) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	$ 44,921	$ 48,554
Current	9,262,898	9,084,447
Loans and Leases Receivable, Gross		9,133,001
Purchased impaired loans		68,664
Total loans and leases	9,307,819	9,201,665
> 90 days past due and still accruing	120	201
Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	14,230	12,923
Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	2,790	7,325
Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	27,901	28,306
Commercial
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	18,894	19,116
Current	2,458,879	2,443,680
Loans and Leases Receivable, Gross		2,462,796
Purchased impaired loans		3,081
Total loans and leases	2,477,773	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	2,305	1,266
Commercial | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	267	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	16,322	14,518
Lease financing
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0	0
Current	82,602	88,364
Loans and Leases Receivable, Gross		88,364
Purchased impaired loans		0
Total loans and leases	82,602	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	500,311	493,167
Loans and Leases Receivable, Gross		493,167
Purchased impaired loans		15
Total loans and leases	500,311	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	4,278,257	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	9,435
Current	3,170,602
Total loans and leases	3,180,037
> 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	7,225
Commercial real estate - investor | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	346
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	1,864
Commercial real estate-owner
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	3,888
Current	1,094,332
Total loans and leases	1,098,220
> 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	1,106
Commercial real estate-owner | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	0
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	2,782
Residential real estate
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	6,980	14,991
Current	1,054,812	1,014,138
Loans and Leases Receivable, Gross		1,029,129
Purchased impaired loans		26,820
Total loans and leases	1,061,792	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	1,710	8,032
Residential real estate | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	990	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	4,280	5,031
Home equity
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	4,699	6,408
Current	776,544	762,863
Loans and Leases Receivable, Gross		769,271
Purchased impaired loans		2,598
Total loans and leases	781,243	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	1,428	2,530
Home equity | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	852	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	2,419	2,795
Installment
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	190	309
Current	79,895	82,022
Loans and Leases Receivable, Gross		82,331
Purchased impaired loans		258
Total loans and leases	80,085	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	73	111
Installment | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	5	50
Installment | Financial Asset, Equal to or Greater than 90 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	112	148
Credit card
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	835	484
Current	44,921	48,700
Loans and Leases Receivable, Gross		49,184
Purchased impaired loans		0
Total loans and leases	45,756	49,184
> 90 days past due and still accruing	120	201
Credit card | Financial Asset, 30 to 59 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	383	208
Credit card | Financial Asset, 60 to 89 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Financing Receivable, Past Due	330	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	$ 122	$ 201