Loans Receivable, Net - Recorded Investment in Non-Accrual Loans by Loan Portfolio Segment Excluding PCI Loans (Detail) - USD ($)	Sep. 30, 2015	Dec. 31, 2014
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 24,394,000	$ 18,307,000
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	1,741,000	1,877,000
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	115,000	557,000
Residential Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	5,481,000	3,115,000
Commercial Real Estate [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 17,057,000	$ 12,758,000