LOANS - Commercial and Consumer Credit Exposure by Risk Attribute (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment [Line Items]
Commercial & industrial	$ 2,514,661	$ 1,912,743
Real Estate - Construction	548,935	467,730
Real Estate - Commercial	3,754,681	2,490,091
Lease financing	93,415	89,347
Total Commercial	6,911,692	4,959,911
Pass
Financing Receivable, Recorded Investment [Line Items]
Commercial & industrial	2,432,834	1,882,464
Real Estate - Construction	548,323	467,687
Real Estate - Commercial	3,664,434	2,446,999
Lease financing	90,902	88,078
Total Commercial	6,736,493	4,885,228
Special Mention
Financing Receivable, Recorded Investment [Line Items]
Commercial & industrial	24,594	6,226
Real Estate - Construction	603	0
Real Estate - Commercial	38,653	4,436
Lease financing	0	0
Total Commercial	63,850	10,662
Substandard
Financing Receivable, Recorded Investment [Line Items]
Commercial & industrial	57,233	24,053
Real Estate - Construction	9	43
Real Estate - Commercial	51,594	38,656
Lease financing	2,513	1,269
Total Commercial	111,349	64,021
Doubtful
Financing Receivable, Recorded Investment [Line Items]
Commercial & industrial	0	0
Real Estate - Construction	0	0
Real Estate - Commercial	0	0
Lease financing	0	0
Total Commercial	0	0
Residential Real Estate [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	955,646	471,391
Residential Real Estate [Member] \| Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	939,936	463,459
Residential Real Estate [Member] \| Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	15,710	7,932
Home Equity Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	817,282	493,604
Home Equity Loan [Member] \| Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	811,108	489,148
Home Equity Loan [Member] \| Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	6,174	4,456
Consumer Loan [Member]
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	93,212	41,586
Consumer Loan [Member] \| Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	93,038	41,331
Consumer Loan [Member] \| Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	174	255
Credit card
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	46,382	46,691
Credit card \| Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	46,382	46,691
Credit card \| Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	0	0
Installment
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	1,912,522	1,053,272
Installment \| Performing
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	1,890,464	1,040,629
Installment \| Nonperforming
Financing Receivable, Recorded Investment [Line Items]
Loans and Leases Receivable, before Fees, Gross	$ 22,058	$ 12,643

Loans and Leases Receivable, Gross, Total of Commercial, Consumer Real Estate/Construction and Commercial Mortgage

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Amount before allowance of commercial leases and leveraged lease transactions where the entity is long-term creditor. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes leases covered under loss sharing agreements.

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Amount before allowance of loans issued to commercial and industrial institutions. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes real estate loans and loans covered under loss sharing agreements.

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Amount before allowance of commercial construction loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans covered under loss sharing agreements.

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