Allowance for Loan Losses and Recorded Investment in Loans by Portfolio Segment Based on Impairment Method (Detail) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Dec. 31, 2012	Mar. 31, 2012	Dec. 31, 2011
Ending allowance balance attributable to loans:
Individually evaluated for impairment	$ 2,171	$ 2,732
Collectively evaluated for impairment	8,279	9,137
Total ending allowance balance	10,450	11,869	17,752	17,299
Loans:
Loans individually evaluated for impairment	34,674	44,376
Loans collectively evaluated for impairment	210,433	218,750
Total ending loans balance	245,107	263,126
One-to-four units
Ending allowance balance attributable to loans:
Individually evaluated for impairment	587	719
Collectively evaluated for impairment	1,247	1,341
Total ending allowance balance	1,834	2,060
Loans:
Loans individually evaluated for impairment	3,760	4,576
Loans collectively evaluated for impairment	51,436	53,157
Total ending loans balance	55,196	57,733
Five or more units
Ending allowance balance attributable to loans:
Individually evaluated for impairment	26	125
Collectively evaluated for impairment	1,097	1,997
Total ending allowance balance	1,123	2,122
Loans:
Loans individually evaluated for impairment	2,382	3,766
Loans collectively evaluated for impairment	75,939	79,584
Total ending loans balance	78,321	83,350
Commercial real estate
Ending allowance balance attributable to loans:
Individually evaluated for impairment	59	543
Collectively evaluated for impairment	1,490	2,142
Total ending allowance balance	1,549	2,685
Loans:
Loans individually evaluated for impairment	6,136	10,364
Loans collectively evaluated for impairment	28,924	30,760
Total ending loans balance	35,060	41,124
Church
Ending allowance balance attributable to loans:
Individually evaluated for impairment	1,333	1,276
Collectively evaluated for impairment	4,344	3,542
Total ending allowance balance	5,677	4,818
Loans:
Loans individually evaluated for impairment	22,230	25,328
Loans collectively evaluated for impairment	50,091	50,926
Total ending loans balance	72,321	76,254
Construction
Ending allowance balance attributable to loans:
Individually evaluated for impairment	0	0
Collectively evaluated for impairment	8	8
Total ending allowance balance	8	8
Loans:
Loans individually evaluated for impairment	0	273
Loans collectively evaluated for impairment	456	462
Total ending loans balance	456	735
Commercial
Ending allowance balance attributable to loans:
Individually evaluated for impairment	97	0
Collectively evaluated for impairment	84	98
Total ending allowance balance	181	98
Loans:
Loans individually evaluated for impairment	97	0
Loans collectively evaluated for impairment	3,526	3,826
Total ending loans balance	3,623	3,826
Consumer
Ending allowance balance attributable to loans:
Individually evaluated for impairment	69	69
Collectively evaluated for impairment	9	9
Total ending allowance balance	78	78
Loans:
Loans individually evaluated for impairment	69	69
Loans collectively evaluated for impairment	61	35
Total ending loans balance	$ 130	$ 104