Loans Receivable, Net - Risk Category of Loans by Class of Loans (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012
Financing Receivable, Recorded Investment [Line Items]
Loan	$ 534,251	$ 533,122
Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	63,747	57,967
Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	457,515	463,287
Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	12,989	11,868
Pass [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	499,300	497,614
Pass [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	63,374	57,341
Pass [Member] | Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	423,915	429,393
Pass [Member] | Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	12,011	10,880
Special Mention [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	2,281	2,281
Special Mention [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan
Special Mention [Member] | Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	1,775	1,775
Special Mention [Member] | Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	506	506
Substandard [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	31,808	32,148
Substandard [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	373	391
Substandard [Member] | Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	30,963	31,275
Substandard [Member] | Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	472	482
Doubtful [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	862	1,079
Doubtful [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan		235
Doubtful [Member] | Commercial Real Estate [Member] | Commercial [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan	862	844
Doubtful [Member] | Commercial Real Estate [Member] | Construction and Land [Member]
Financing Receivable, Recorded Investment [Line Items]
Loan