Loans and Allowance For Credit Losses - Summary of Aging Analysis of the Loan Portfolio by the Time Past Due (Detail) - USD ($) $ in Thousands	Sep. 30, 2021	Dec. 31, 2020
Financing Receivable, Past Due [Line Items]
Total	$ 1,301,972	$ 1,369,070
Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Total	428,169	414,548
Real Estate - Other [Member] | Over 60 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	191
Real Estate - Construction & Land [Member]
Financing Receivable, Past Due [Line Items]
Total	41,312	37,193
SBA [Member]
Financing Receivable, Past Due [Line Items]
Total	107,096	317,564
Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Total	61,193	49,075
Loans Receivable [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,233	234
Current	1,300,414	1,367,331
Total	1,301,972	1,369,070
Loans Receivable [Member] | Over 30 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	134	1,505
Loans Receivable [Member] | Over 60 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	191
Loans Receivable [Member] | Commercial And Industrial [Member]
Financing Receivable, Past Due [Line Items]
Current	428,035	414,548
Total	428,169	414,548
Loans Receivable [Member] | Commercial And Industrial [Member] | Over 30 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	134
Loans Receivable [Member] | Real Estate - Other [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	1,000
Current	663,011	549,185
Total	664,202	550,690
Loans Receivable [Member] | Real Estate - Other [Member] | Over 30 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	0	1,505
Loans Receivable [Member] | Real Estate - Construction & Land [Member]
Financing Receivable, Past Due [Line Items]
Current	41,312	37,193
Total	41,312	37,193
Loans Receivable [Member] | SBA [Member]
Financing Receivable, Past Due [Line Items]
Nonaccrual	233	234
Current	106,863	317,330
Total	107,096	317,564
Loans Receivable [Member] | SBA [Member] | Over 30 Days Past Due [Member]
Financing Receivable, Past Due [Line Items]
Current	0
Loans Receivable [Member] | Other Loans [Member]
Financing Receivable, Past Due [Line Items]
Current	61,193	49,075
Total	$ 61,193	$ 49,075