Loans Receivable, Net - Recorded Investment in Non-Accrual Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 17,415	$ 20,865	$ 13,600
Commercial and industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	1,587	503
Commercial real estate - owner occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	501	5,962
Commercial real estate – investor
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	5,024	8,281
Residential mortgage
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	7,389	4,190
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 2,914	$ 1,929