Loans Receivable, Net - Recorded Investment in Non-Accrual Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 18,251	$ 20,865
Residential Real Estate
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	5,686	4,190
Commercial Real Estate - Owner Occupied
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	862	5,962
Commercial Real Estate - Investor
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	7,994	8,281
Consumer
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	1,992	1,929
Commercial and Industrial
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 1,717	$ 503