Loans Receivable and Allowance for Loan Losses - Analysis of Loans Modified in Troubled Debt Restructuring by Type of Concession (Detail) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015	Jun. 30, 2014	Jun. 30, 2015	Jun. 30, 2014
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	$ 5,012	$ 343	$ 5,417	$ 717
Interest-rate reductions
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	5,012	176	5,417	550
Extended under forbearance
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring		167		167
TDRs in Compliance with Their Modified Terms and Accruing Interest
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	2,484	167	2,682	414
TDRs in Compliance with Their Modified Terms and Accruing Interest | Interest-rate reductions
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	2,484	0	2,682	247
TDRs in Compliance with Their Modified Terms and Accruing Interest | Extended under forbearance
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring		167		167
TDRs in Compliance with Their Modified Terms and Not Accruing Interest
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	2,528	176	2,735	303
TDRs in Compliance with Their Modified Terms and Not Accruing Interest | Interest-rate reductions
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring	$ 2,528	176	$ 2,735	303
TDRs in Compliance with Their Modified Terms and Not Accruing Interest | Extended under forbearance
Financing Receivable, Modifications [Line Items]
Amount of loans modified in troubled debt restructuring		$ 0		$ 0