Loans Receivable and Allowance for Loan Losses - Additional Information (Detail) $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2015 USD ($) Loan Allowance Commitment	Jun. 30, 2014 USD ($) Loan Allowance	Jun. 30, 2015 USD ($) Allowance Commitment	Jun. 30, 2014 USD ($) Loan Allowance	Dec. 31, 2014 USD ($) Commitment
Financing Receivable, Modifications [Line Items]
FDIC Loss Sharing Arrangement, Clawback Liability Payment Date			45 days
FDIC Loss Sharing Arrangement, Clawback Liability	$ 2,400		$ 2,400
FDIC Loss Sharing Arrangement, Expected FDIC Receivable	1,000		1,000
FDIC Loss Sharing Arrangement, Clawback Liability Net of FDIC Receivable	1,500		1,500
Loans Receivables Gross Troubled Debt Restructurings	$ 10,000		$ 10,000		$ 5,000
Financing Receivable Impairment Modification Minimum Period			6 months
Number Of Commitments To Lend Additional Funds For Troubled Debt Restructurings | Commitment	0		0		0
Loans Receivables Gross Troubled Debt Restructurings Performing Amount	$ 5,000	$ 5,400	$ 5,000	$ 5,400
Specific Allowance, Loans Modified In Troubled Debt Restructurings | Allowance	2	2	2	2
Funds For Reimbursement Relating To Purchased Manufactured Housing	$ 1,600		$ 1,600		$ 3,000
Troubled Debt Restructurings
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loan		0		0
TDRs in Compliance with Their Modified Terms and Not Accruing Interest
Financing Receivable, Modifications [Line Items]
Recorded Investment	$ 2,528	$ 176	$ 2,735	$ 303
Commercial and industrial (including owner occupied commercial real estate)
Financing Receivable, Modifications [Line Items]
Specific Allowance, Loans Modified In Troubled Debt Restructurings | Allowance	1	1	1	1
Allowance for Credit Losses, Change in Method of Calculating Impairment	$ 70	$ 70	$ 70	$ 70
Commercial and industrial (including owner occupied commercial real estate) | Troubled Debt Restructurings
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loan	2			2
Commercial and industrial (including owner occupied commercial real estate) | TDRs in Compliance with Their Modified Terms and Not Accruing Interest
Financing Receivable, Modifications [Line Items]
Recorded Investment	$ 608		608
Manufactured housing | Troubled Debt Restructurings
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loan	31			33
Manufactured housing | TDRs in Compliance with Their Modified Terms and Not Accruing Interest
Financing Receivable, Modifications [Line Items]
Recorded Investment	$ 1,709	$ 176	$ 1,916	$ 303
Residential real estate
Financing Receivable, Modifications [Line Items]
Specific Allowance, Loans Modified In Troubled Debt Restructurings | Allowance	1	1	1	1
Allowance for Credit Losses, Change in Method of Calculating Impairment	$ 20	$ 20	$ 20	$ 20
Other Real Estate And Foreclosed Assets, Residential	5,000		5,000
Residential Mortgage Loans in Process of Foreclosure Amount	$ 100		100
Residential real estate | Troubled Debt Restructurings
Financing Receivable, Modifications [Line Items]
Financing Receivable, Modifications, Subsequent Default, Number of Contracts | Loan	1			1
Residential real estate | TDRs in Compliance with Their Modified Terms and Not Accruing Interest
Financing Receivable, Modifications [Line Items]
Recorded Investment			$ 211	$ 0
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