CREDIT QUALITY ASSESSMENT (Information by Credit Risk Rating Indicators for Those Remaining Segments of Loan Portfolio) (Detail) - USD ($) $ in Thousands	Mar. 31, 2020	Dec. 31, 2019
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	$ 6,722,992	$ 6,705,232
Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	453,346	466,764
Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	1,116,512	1,149,327
Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment [Line Items]
Total loans and leases	$ 149,573	146,279
Homogeneous Loan Pools
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,762,370
Homogeneous Loan Pools | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		466,764
Homogeneous Loan Pools | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,149,327
Homogeneous Loan Pools | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		146,279
Homogeneous Loan Pools | Performing Financing Receivable
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,744,158
Homogeneous Loan Pools | Performing Financing Receivable | Consumer
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		462,293
Homogeneous Loan Pools | Performing Financing Receivable | Residential Real Estate Portfolio Segment | Residential Mortgage
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,135,586
Homogeneous Loan Pools | Performing Financing Receivable | Residential Real Estate Portfolio Segment | Residential Construction
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		146,279
Homogeneous Loan Pools | Nonperforming Financing Receivable | Loans 90 Days Or More Past Due
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		0
Homogeneous Loan Pools | Nonperforming Financing Receivable | Non-accruing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		16,768
Homogeneous Loan Pools | Nonperforming Financing Receivable | Restructured Loans
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,444
Homogeneous Loan Pools | Nonperforming Financing Receivable | Consumer | Loans 90 Days Or More Past Due
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		0
Homogeneous Loan Pools | Nonperforming Financing Receivable | Consumer | Non-accruing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		4,107
Homogeneous Loan Pools | Nonperforming Financing Receivable | Consumer | Accruing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		364
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Mortgage | Loans 90 Days Or More Past Due
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		0
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Mortgage | Non-accruing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		12,661
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Mortgage | Restructured Loans
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		1,080
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Construction | Loans 90 Days Or More Past Due
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		0
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Construction | Non-accruing [Member]
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		0
Homogeneous Loan Pools | Nonperforming Financing Receivable | Residential Real Estate Portfolio Segment | Residential Construction | Restructured Loans
Financing Receivable Recorded Investment [Line Items]
Total loans and leases		$ 0