LOANS AND ALLOWANCE FOR CREDIT LOSSES - Composition of Nonaccrual Loans (Detail) $ in Thousands	Jun. 30, 2020 USD ($) loan	Dec. 31, 2019 USD ($)
Receivables [Abstract]
Number of past due loans in forbearance or deferment | loan	0
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	$ 72,703	$ 43,354
Non-accrual Loans with no ACL	49,492	16,564
NTM Loans
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	19,199	13,019
Traditional Loans
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	53,504	30,335
Commercial | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	30,398	19,114
Non-accrual Loans with no ACL	10,728	337
Commercial | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	6,633	0
Non-accrual Loans with no ACL	6,632	0
Commercial | SBA
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	5,026	5,230
Non-accrual Loans with no ACL	1,485	1,474
Commercial | Construction
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Non-accrual Loans with no ACL	0	0
Commercial | NTM Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Commercial | NTM Loans | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Commercial | NTM Loans | SBA
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Commercial | NTM Loans | Construction
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Commercial | Traditional Loans | Commercial and industrial
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	30,398	19,114
Commercial | Traditional Loans | Commercial real estate
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	6,633	0
Commercial | Traditional Loans | SBA
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	5,026	5,230
Commercial | Traditional Loans | Construction
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Consumer | Single family residential mortgage
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	28,470	18,625
Non-accrual Loans with no ACL	28,470	14,373
Consumer | Other consumer
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	2,176	385
Non-accrual Loans with no ACL	2,177	380
Consumer | NTM Loans | Single family residential mortgage
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	19,199	13,019
Consumer | NTM Loans | Other consumer
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	0	0
Consumer | Traditional Loans | Single family residential mortgage
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	9,271	5,606
Consumer | Traditional Loans | Other consumer
Financing Receivable, Past Due [Line Items]
Total non-accrual loans	$ 2,176	$ 385