Loans - Allowance for Loan Losses (Detail) (USD $) In Thousands, unless otherwise specified	3 Months Ended
Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Allowance for loan losses:
Allowance for loan losses, beginning of period	$ 17,825	$ 25,596
Provision for loan losses	350	2,700
Loan charge-offs	948	5,250
Loan recoveries	243	342
Net loans charged-off	705	4,908
Allowance for loan losses, end of period	17,470	23,388
Individually evaluated for impairment	3,093	3,759
Collectively evaluated for impairment	14,377	19,629
Loans, gross, end of period:
Total loans, gross	730,764	761,687	738,282
Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	17,470	23,388
Loans, gross, end of period:
Individually evaluated for impairment	43,144	60,531
Collectively evaluated for impairment	687,620	701,156
Commercial real estate [Member]
Allowance for loan losses:
Allowance for loan losses, beginning of period	12,317	18,026
Provision for loan losses	(270)	1,417
Loan charge-offs	464	3,751
Loan recoveries	31	79
Net loans charged-off	433	3,672
Allowance for loan losses, end of period	11,614	15,771
Individually evaluated for impairment	1,995	3,464
Collectively evaluated for impairment	9,619	12,307
Loans, gross, end of period:
Total loans, gross	456,010	470,891	458,436
Commercial real estate [Member] \| Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	11,614	15,771
Loans, gross, end of period:
Individually evaluated for impairment	36,989	55,333
Collectively evaluated for impairment	419,021	415,558
Single-family residential loans [Member]
Allowance for loan losses:
Allowance for loan losses, beginning of period	3,140	4,488
Provision for loan losses	(101)	1,024
Loan charge-offs	133	1,023
Loan recoveries	43	45
Net loans charged-off	90	978
Allowance for loan losses, end of period	2,949	4,534
Individually evaluated for impairment	214	204
Collectively evaluated for impairment	2,735	4,330
Loans, gross, end of period:
Total loans, gross	166,389	179,815
Single-family residential loans [Member] \| Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	2,949	4,534
Loans, gross, end of period:
Individually evaluated for impairment	3,056	3,479
Collectively evaluated for impairment	163,333	176,336
Commercial and Industrial [Member]
Allowance for loan losses:
Allowance for loan losses, beginning of period	1,264	1,862
Provision for loan losses	655	94
Loan charge-offs	39	74
Loan recoveries	10	19
Net loans charged-off	29	55
Allowance for loan losses, end of period	1,890	1,901
Individually evaluated for impairment	880	86
Collectively evaluated for impairment	1,010	1,815
Loans, gross, end of period:
Total loans, gross	49,620	50,594
Commercial and Industrial [Member] \| Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	1,890	1,901
Loans, gross, end of period:
Individually evaluated for impairment	3,062	1,677
Collectively evaluated for impairment	46,558	48,917
Consumer [Member]
Allowance for loan losses:
Allowance for loan losses, beginning of period	1,093	1,209
Provision for loan losses	(17)	100
Loan charge-offs	97	241
Loan recoveries	34	61
Net loans charged-off	63	180
Allowance for loan losses, end of period	1,013	1,129
Individually evaluated for impairment	4	5
Collectively evaluated for impairment	1,009	1,124
Loans, gross, end of period:
Total loans, gross	49,051	52,100
Consumer [Member] \| Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	1,013	1,129
Loans, gross, end of period:
Individually evaluated for impairment	37	42
Collectively evaluated for impairment	49,014	52,058
Other [Member]
Allowance for loan losses:
Allowance for loan losses, beginning of period	11	11
Provision for loan losses	83	65
Loan charge-offs	215	161
Loan recoveries	125	138
Net loans charged-off	90	23
Allowance for loan losses, end of period	4	53
Collectively evaluated for impairment	4	53
Loans, gross, end of period:
Total loans, gross	9,694	8,287
Other [Member] \| Loans Receivable [Member]
Allowance for loan losses:
Allowance for loan losses, end of period	4	53
Loans, gross, end of period:
Collectively evaluated for impairment	$ 9,694	$ 8,287

Allowance for loan and lease losses write offs net of recoveries.

No definition available.

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- Definition

Reflects a reduction in bad debt expense attributable to collections of loans and lease receivables which had previously been fully or partially charged off as bad debts.

+ References

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-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 114

-Paragraph 20

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- Definition

Reflects the amount of loans and leases that have been removed, or charged off, from both loan receivables and the reserve for credit losses, typically because they are considered to be not salvageable or have been purchased by unconsolidated collection entities.

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- Definition

The valuation allowance for financing receivables that are expected to be uncollectible that were collectively evaluated for impairment.

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- Definition

Amount of valuation allowance for financing receivables that are expected to be uncollectible that were individually evaluated for impairment.

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- Definition

The balance of financing receivables that were collectively evaluated for impairment.

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The balance of financing receivables that were individually evaluated for impairment.

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- Definition

Amount of allowance to cover probable credit losses on loans and leases. Includes carryover of or adjustments to the allowance for loan losses in connection with business combinations. Excludes allowance for loans and leases covered under loss sharing agreements.

+ References

Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher FASB

-Name Statement of Financial Accounting Standard (FAS)

-Number 5

-Paragraph 8, 9

-LegacyDoc This reference is SUPERSEDED by the Accounting Standards Codification effective for interim and annual periods ending after September 15, 2009. This reference is included to help users transition from the previous accounting hierarchy and will be removed from future versions of this taxonomy.

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Reference 7: http://www.xbrl.org/2003/role/presentationRef

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-Number Topic 6

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- Definition

Amount before allowance of loans and leases held in portfolio, including but not limited to, commercial and consumer loans. Includes deferred interest and fees, undisbursed portion of loan balance, unamortized costs and premiums and discounts from face amounts. Excludes loans and leases covered under loss sharing agreements.

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-Name Statement of Position (SOP)

-Number 01-6

-Paragraph 13

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- Definition

Provision charged for the period based on estimated losses to be realized from loan and lease transactions.

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Reference 1: http://www.xbrl.org/2003/role/presentationRef

-Publisher AICPA

-Name Audit and Accounting Guide (AAG)

-Number AAG-DEP

-Paragraph 168, 169, 170

-IssueDate 2006-05-01

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