CREDIT QUALITY ASSESSMENT - Information on the credit quality of loan portfolio under the new CECL (Detail) $ in Thousands	12 Months Ended
	Dec. 31, 2020 USD ($)
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	$ 38,632
Loans placed on non-accrual	85,300
Commercial real estate: | Commercial investor real estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	8,437
Commercial real estate: | Commercial owner-occupied real estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	4,148
Commercial real estate: | Commercial AD&C
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	829
Commercial Business
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	8,450
Residential real estate: | Residential mortgage
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	12,661
Residential real estate: | Residential construction
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	0
Consumer
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	4,107
Non-accrual status
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	38,632
PCD loans designated as non-accrual	13,084
Loans placed on non-accrual	85,286
Non-accrual balances transferred to OREO	(70)
Non-accrual balances charged-off	(1,394)
Net payments or draws	(21,201)
Non-accrual loans brought current	(1,976)
Balance at end of period	112,361
Non-accrual status | Commercial real estate: | Commercial investor real estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	8,437
PCD loans designated as non-accrual	9,544
Loans placed on non-accrual	37,882
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	(411)
Net payments or draws	(10,225)
Non-accrual loans brought current	0
Balance at end of period	45,227
Non-accrual status | Commercial real estate: | Commercial owner-occupied real estate
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	4,148
PCD loans designated as non-accrual	0
Loans placed on non-accrual	8,572
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	0
Net payments or draws	(1,059)
Non-accrual loans brought current	(100)
Balance at end of period	11,561
Non-accrual status | Commercial real estate: | Commercial AD&C
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	829
PCD loans designated as non-accrual	0
Loans placed on non-accrual	15,844
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	0
Net payments or draws	(1,629)
Non-accrual loans brought current	0
Balance at end of period	15,044
Non-accrual status | Commercial Business
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	8,450
PCD loans designated as non-accrual	2,539
Loans placed on non-accrual	17,442
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	(446)
Net payments or draws	(4,169)
Non-accrual loans brought current	(883)
Balance at end of period	22,933
Non-accrual status | Residential real estate: | Residential mortgage
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	12,661
PCD loans designated as non-accrual	8
Loans placed on non-accrual	1,485
Non-accrual balances transferred to OREO	(70)
Non-accrual balances charged-off	(416)
Net payments or draws	(2,598)
Non-accrual loans brought current	(858)
Balance at end of period	10,212
Non-accrual status | Residential real estate: | Residential construction
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	0
PCD loans designated as non-accrual	0
Loans placed on non-accrual	0
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	0
Net payments or draws	0
Non-accrual loans brought current	0
Balance at end of period	0
Non-accrual status | Consumer
Accounts Receivable, Allowance for Credit Loss [Roll Forward]
Balance at beginning of period	4,107
PCD loans designated as non-accrual	993
Loans placed on non-accrual	4,061
Non-accrual balances transferred to OREO	0
Non-accrual balances charged-off	(121)
Net payments or draws	(1,521)
Non-accrual loans brought current	(135)
Balance at end of period	$ 7,384