Note 4. Loans Receivable (Detail) - Impaired Loans (USD $) In Thousands, unless otherwise specified																																													3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended			3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended	6 Months Ended	3 Months Ended	6 Months Ended		3 Months Ended		6 Months Ended		3 Months Ended		6 Months Ended
	Jun. 30, 2012 Unpaid Principal Balance [Member] One-to-Four-Family Residential [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Home Equity and Second Mortgage [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Multifamily Residential [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Multifamily Residential [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Commercial Real Estate Loans [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Other Construction and Land [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Other Construction and Land [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Commercial Loans [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Commercial Loans [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member] Consumer Loans [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member] Consumer Loans [Member]	Jun. 30, 2012 Unpaid Principal Balance [Member]	Dec. 31, 2011 Unpaid Principal Balance [Member]	Jun. 30, 2012 Recorded Investment [Member] One-to-Four-Family Residential [Member]	Dec. 31, 2011 Recorded Investment [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Dec. 31, 2011 Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Recorded Investment [Member] Multifamily Residential [Member]	Dec. 31, 2011 Recorded Investment [Member] Multifamily Residential [Member]	Jun. 30, 2012 Recorded Investment [Member] Commercial Real Estate Loans [Member]	Dec. 31, 2011 Recorded Investment [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Recorded Investment [Member] Other Construction and Land [Member]	Dec. 31, 2011 Recorded Investment [Member] Other Construction and Land [Member]	Jun. 30, 2012 Recorded Investment [Member] Commercial Loans [Member]	Dec. 31, 2011 Recorded Investment [Member] Commercial Loans [Member]	Jun. 30, 2012 Recorded Investment [Member] Consumer Loans [Member]	Dec. 31, 2011 Recorded Investment [Member] Consumer Loans [Member]	Jun. 30, 2012 Recorded Investment [Member]	Dec. 31, 2011 Recorded Investment [Member]	Jun. 30, 2012 Valuation Allowance [Member] One-to-Four-Family Residential [Member]	Dec. 31, 2011 Valuation Allowance [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Valuation Allowance [Member] Home Equity and Second Mortgage [Member]	Dec. 31, 2011 Valuation Allowance [Member] Home Equity and Second Mortgage [Member]	Dec. 31, 2011 Valuation Allowance [Member] Multifamily Residential [Member]	Jun. 30, 2012 Valuation Allowance [Member] Commercial Real Estate Loans [Member]	Dec. 31, 2011 Valuation Allowance [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Valuation Allowance [Member] Other Construction and Land [Member]	Dec. 31, 2011 Valuation Allowance [Member] Other Construction and Land [Member]	Dec. 31, 2011 Valuation Allowance [Member] Consumer Loans [Member]	Jun. 30, 2012 Valuation Allowance [Member]	Dec. 31, 2011 Valuation Allowance [Member]	Jun. 30, 2012 Average Recorded Investment [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2011 Average Recorded Investment [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Average Recorded Investment [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2011 Average Recorded Investment [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Multifamily Residential [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Multifamily Residential [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Multifamily Residential [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Multifamily Residential [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] One-to-Four-Family Construction [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Other Construction and Land [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Other Construction and Land [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Other Construction and Land [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Other Construction and Land [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Commercial Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Commercial Loans [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Commercial Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Commercial Loans [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Consumer Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Consumer Loans [Member]	Jun. 30, 2012 Average Recorded Investment [Member] Consumer Loans [Member]	Jun. 30, 2011 Average Recorded Investment [Member] Consumer Loans [Member]	Jun. 30, 2012 Average Recorded Investment [Member]	Jun. 30, 2011 Average Recorded Investment [Member]	Jun. 30, 2012 Average Recorded Investment [Member]	Jun. 30, 2011 Average Recorded Investment [Member]	Jun. 30, 2012 Interest Income Recognized [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2011 Interest Income Recognized [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Interest Income Recognized [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2011 Interest Income Recognized [Member] One-to-Four-Family Residential [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Home Equity and Second Mortgage [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Multifamily Residential [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Multifamily Residential [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Multifamily Residential [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Multifamily Residential [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Commercial Real Estate Loans [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Other Construction and Land [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Other Construction and Land [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Other Construction and Land [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Other Construction and Land [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Commercial Loans [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Commercial Loans [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Consumer Loans [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Consumer Loans [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Consumer Loans [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Interest Income Based on Original Terms [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Interest Income Based on Original Terms [Member]	Jun. 30, 2012 Interest Income Recognized [Member] Interest Income Based on Original Terms [Member]	Jun. 30, 2011 Interest Income Recognized [Member] Interest Income Based on Original Terms [Member]	Jun. 30, 2012 Interest Income Recognized [Member]	Jun. 30, 2011 Interest Income Recognized [Member]	Jun. 30, 2012 Interest Income Recognized [Member]	Jun. 30, 2011 Interest Income Recognized [Member]
Impaired loans with a valuation allowance unpaid principal balance	$ 1,686	$ 3,019	$ 157	$ 108		$ 2,958	$ 4,313	$ 4,301	$ 2,097	$ 925				$ 70	$ 8,253	$ 11,381
Impaired loans with a valuation allowance recorded investment																	1,482	2,714	20	27		2,255	3,429	2,422	1,774	645				25	6,705	8,088
Impaired loans with a valuation allowance valuation allowance																																	204	305	137	81	703	884	1,879	323	280	45	1,548	3,293
Impaired loans with a valuation allowance average recorded investment																																													2,797	4,478	2,769	4,013	20	155	22	217		4,997	752	5,073	2,791	1,542	2,668	2,341	3	1,958	4,214	1,520	4,003		107		180		10	8	16	7,566	15,503	7,739	15,846
Impaired loans with a valuation allowance interest income recognized																																																																														6	5		20		1		3					17		40	13		1	9	12					1					23	7	49	49
Impaired loans without a valuation allowance unpaid principal balance	6,467	10,066	449	723	279	5,175	5,379	8,937	6,520	2,758	402	72	91	49	19,587	27,780
Impaired loans without a valuation allowance recorded investment																	6,467	10,066	449	723	279	5,175	5,379	8,937	6,520	2,758	402	72	91	49	19,587	27,780
Impaired loans without a valuation allowance average recorded investment																																													6,248	18,153	7,520	19,398	479	932	560	903	2,026	4,130	3,076	3,967	6,320	12,735	7,192	10,757		4,121	2,740	3,667	3,300	443	431	319	407	73	91	65	93	19,710	39,212	22,399	38,825
Impaired loans without a valuation allowance interest income recognized																																																																														24	82	52	158	1	19	5	36	3	45	7	85	31	62	84	137	22	13	89	30	1	3	1	1	3					81	223	238	452
Total impaired loans															27,840	39,161
Total impaired loans																															26,292	35,868
Total impaired loans																																	204	305	137	81	703	884	1,879	323	280	45	1,548	3,293
Total impaired loans																																																																										27,276	54,715	30,138	54,671
Total impaired loans																																																																																																							430	864	856	1,675	104	230	287	501
Interest based on original terms																																																																																																							430	864	856	1,675	104	230	287	501
Interest income recognized on a cash basis on impaired loans																																																																																																											$ 107	$ 143	$ 203	$ 269