Loans Receivable, Net - Recorded Investment in Non-Accrual Loans by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 18,307	$ 45,360	$ 43,374
Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	1,877	4,328
Commercial and Industrial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	557	515
Residential Real Estate [Member] | Residential [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	3,115	28,213
Residential Real Estate [Member] | Consumer [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	1,877	4,328
Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	12,558	11,995
Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment, Past Due [Line Items]
Recorded Investment in Non-accrual Loans	$ 200	$ 309