Loans Receivable and Allowance for Loan Losses - Additional Information (Detail) (USD $)	3 Months Ended
	Mar. 31, 2015 Commitment	Mar. 31, 2014 Loan Commitment	Dec. 31, 2014
Financing Receivable, Modifications [Line Items]
Loans Receivables Gross Troubled Debt Restructurings	$ 5,200,000	$ 5,100,000
Financing Receivable Impairment Modification Minimum Period	6 months
Number Of Commitments To Lend Additional Funds For Troubled Debt Restructurings	0	0
Loans Receivables Gross Troubled Debt Restructurings Performing Amount	400,000	400,000
Recorded Investment	200,000	100,000
Financing Receivable Modifications Number Of Loans		2
Funds For Reimbursement Relating To Purchased Manufactured Housing	1,100,000		3,000,000
Troubled Debt Restructurings
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts		0
Specific Allowance Allocations On Loans Modified In Troubled Debt Restructurings	0	0
Troubled Debt Restructurings | Manufactured housing
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts	2
Residential real estate
Financing Receivable, Modifications [Line Items]
Other Real Estate And Foreclosed Assets, Residential	5,300,000
Residential Mortgage Loans in Process of Foreclosure Amount	$ 200,000
Non Single Family Loans
Financing Receivable, Modifications [Line Items]
Loss Sharing Arrangements For Loans Expire Period	Third quarter 2015
Single Family Loans
Financing Receivable, Modifications [Line Items]
Loss Sharing Arrangements For Loans Expire Period	Third quarter 2020