Loans, Nonaccrual and past due loans (Details) (USD $)	3 Months Ended
	Mar. 31, 2013 Contract	Mar. 31, 2012 Contract	Dec. 31, 2012	Mar. 30, 2012 Loan
Past due and nonaccrual [Line Items]
Nonaccrual loans	$ 1,555,000		$ 3,003,000
30 to 59 days past due	3,890,000		3,821,000
60 to 89 days past due	343,000		940,000
Greater than 90 days past due	1,449,000		1,720,000
Recorded investment 90 days or greater and accruing	0		81,000
Total past due	5,682,000		6,562,000
Current	335,267,000		322,739,000
Loans	340,949,000		329,301,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	4,515,000		6,606,000
With related allowance recorded	6,353,000		5,387,000
Total investments	10,868,000		11,993,000
With no related allowance unpaid principal balance	4,975,000		7,247,000
With related allowance unpaid principal balance	6,623,000		5,582,000
Total unpaid principal balance	11,598,000		12,829,000
Related allowance	1,006,000		1,018,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	11,432,000	11,489,000
Interest income recognized	93,000	93,000
Impaired loans, interest income forgone	87,000	78,000
Commitments to lend additional funds to borrowers whose loans were classified as nonaccrual, TDR or impaired	0		0
Trouble debt restructuring, recorded investment	6,900,000	7,700,000
Restructured loans by modification [Abstract]
Number of contracts	3	7
Rate modifications	0	121,000
Term modifications	0	0
Payment modifications	0	0
Combination modifications	878,000	552,000
Total modifications	878,000	673,000
TDR modifications, subsequent default	857,000	4,672,000
Loans that became delinquent more than 90 days past due or transferred to nonaccrual within 12 months of restructuring [Abstract]
Number of days past due to be considered in default	31 days
Number of days past due to be considered nonaccrual status	90 days
One-to four- family [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	1,234,000		1,013,000
30 to 59 days past due	2,450,000		2,238,000
60 to 89 days past due	0		572,000
Greater than 90 days past due	1,128,000		836,000
Recorded investment 90 days or greater and accruing	0		81,000
Total past due	3,578,000		3,727,000
Current	95,415,000		92,057,000
Loans	98,993,000		95,784,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	2,160,000		2,521,000
With related allowance recorded	4,145,000		3,495,000
Total investments	6,305,000		6,016,000
With no related allowance unpaid principal balance	2,478,000		2,826,000
With related allowance unpaid principal balance	4,351,000		3,651,000
Total unpaid principal balance	6,829,000		6,477,000
Related allowance	336,000		392,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	6,161,000	5,866,000
Interest income recognized	40,000	40,000
Restructured loans by modification [Abstract]
Number of contracts	3	2
Rate modifications	0	0
Term modifications	0	0
Payment modifications	0	0
Combination modifications	878,000	88,000
Total modifications	878,000	88,000
TDR modifications, subsequent default	202,000	2,749,000
Loans that became delinquent more than 90 days past due or transferred to nonaccrual within 12 months of restructuring [Abstract]
Number of mortgages over 90 days past due and considered nonaccrual status				1
Home equity [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	306,000		332,000
30 to 59 days past due	759,000		886,000
60 to 89 days past due	305,000		364,000
Greater than 90 days past due	306,000		332,000
Recorded investment 90 days or greater and accruing	0		0
Total past due	1,370,000		1,582,000
Current	33,969,000		33,782,000
Loans	35,339,000		35,364,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	799,000		949,000
With related allowance recorded	949,000		782,000
Total investments	1,748,000		1,731,000
With no related allowance unpaid principal balance	899,000		1,132,000
With related allowance unpaid principal balance	1,014,000		782,000
Total unpaid principal balance	1,912,000		1,914,000
Related allowance	334,000		247,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	1,740,000	1,611,000
Interest income recognized	9,000	9,000
Restructured loans by modification [Abstract]
Number of contracts	0	1
Rate modifications	0	0
Term modifications	0	0
Payment modifications	0	0
Combination modifications	0	49,000
Total modifications	0	49,000
TDR modifications, subsequent default	115,000	767,000
Commercial and multifamily [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	0		1,106,000
30 to 59 days past due	0		0
60 to 89 days past due	0		0
Greater than 90 days past due	0		0
Recorded investment 90 days or greater and accruing	0		0
Total past due	0		0
Current	133,178,000		133,620,000
Loans	133,178,000		133,620,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	772,000		1,883,000
With related allowance recorded	243,000		244,000
Total investments	1,015,000		2,127,000
With no related allowance unpaid principal balance	772,000		1,883,000
With related allowance unpaid principal balance	242,000		244,000
Total unpaid principal balance	1,015,000		2,127,000
Related allowance	69,000		70,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	1,571,000	3,527,000
Interest income recognized	3,000	3,000
Restructured loans by modification [Abstract]
Number of contracts	0	1
Rate modifications	0	0
Term modifications	0	0
Payment modifications	0	0
Combination modifications	0	243,000
Total modifications	0	243,000
Construction and land [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	0		471,000
30 to 59 days past due	134,000		243,000
60 to 89 days past due	0		0
Greater than 90 days past due	0		471,000
Recorded investment 90 days or greater and accruing	0		0
Total past due	134,000		714,000
Current	34,379,000		24,744,000
Loans	34,513,000		25,458,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	23,000		495,000
With related allowance recorded	76,000		76,000
Total investments	99,000		571,000
With no related allowance unpaid principal balance	23,000		608,000
With related allowance unpaid principal balance	76,000		76,000
Total unpaid principal balance	99,000		684,000
Related allowance	25,000		25,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	335,000	0
Interest income recognized	0	0
Manufactured homes [Member]
Past due and nonaccrual [Line Items]
30 to 59 days past due	152,000		326,000
60 to 89 days past due	21,000		2,000
Greater than 90 days past due	0		0
Recorded investment 90 days or greater and accruing	0		0
Total past due	173,000		328,000
Current	15,403,000		15,904,000
Loans	15,576,000		16,232,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	100,000		67,000
With related allowance recorded	523,000		587,000
Total investments	623,000		654,000
With no related allowance unpaid principal balance	100,000		67,000
With related allowance unpaid principal balance	523,000		587,000
Total unpaid principal balance	623,000		654,000
Related allowance	107,000		117,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	639,000	118,000
Interest income recognized	4,000	4,000
Restructured loans by modification [Abstract]
TDR modifications, subsequent default	0	574,000
Other consumer [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	3,000		1,000
30 to 59 days past due	27,000		65,000
60 to 89 days past due	17,000		2,000
Greater than 90 days past due	3,000		1,000
Recorded investment 90 days or greater and accruing	0		0
Total past due	47,000		68,000
Current	8,732,000		8,582,000
Loans	8,779,000		8,650,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	7,000		9,000
With related allowance recorded	44,000		46,000
Total investments	51,000		55,000
With no related allowance unpaid principal balance	49,000		49,000
With related allowance unpaid principal balance	44,000		46,000
Total unpaid principal balance	93,000		95,000
Related allowance	27,000		22,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	53,000	90,000
Interest income recognized	0	0
Restructured loans by modification [Abstract]
Number of contracts	0	1
Rate modifications	0	0
Term modifications	0	0
Payment modifications	0	0
Combination modifications	0	12,000
Total modifications	0	12,000
TDR modifications, subsequent default	0	42,000
Commercial business [Member]
Past due and nonaccrual [Line Items]
Nonaccrual loans	12,000		80,000
30 to 59 days past due	368,000		63,000
60 to 89 days past due	0		0
Greater than 90 days past due	12,000		80,000
Recorded investment 90 days or greater and accruing	0		0
Total past due	380,000		143,000
Current	14,191,000		14,050,000
Loans	14,571,000		14,193,000
Impaired Financing Receivable, Recorded Investment [Abstract]
With no related allowance recorded	654,000		682,000
With related allowance recorded	373,000		157,000
Total investments	1,027,000		839,000
With no related allowance unpaid principal balance	654,000		682,000
With related allowance unpaid principal balance	373,000		196,000
Total unpaid principal balance	1,027,000		878,000
Related allowance	108,000		145,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	933,000	278,000
Interest income recognized	37,000	37,000
Restructured loans by modification [Abstract]
Number of contracts	0	2
Rate modifications	0	121,000
Term modifications	0	0
Payment modifications	0	0
Combination modifications	0	160,000
Total modifications	0	281,000
TDR modifications, subsequent default	540,000	540,000
Performing [Member]
Past due and nonaccrual [Line Items]
Loans	338,654,000		325,389,000
Performing [Member] | One-to four- family [Member]
Past due and nonaccrual [Line Items]
Loans	97,710,000		94,641,000
Performing [Member] | Home equity [Member]
Past due and nonaccrual [Line Items]
Loans	34,697,000		34,647,000
Performing [Member] | Commercial and multifamily [Member]
Past due and nonaccrual [Line Items]
Loans	132,938,000		132,273,000
Performing [Member] | Construction and land [Member]
Past due and nonaccrual [Line Items]
Loans	34,513,000		24,987,000
Performing [Member] | Manufactured homes [Member]
Past due and nonaccrual [Line Items]
Loans	15,576,000		16,203,000
Performing [Member] | Other consumer [Member]
Past due and nonaccrual [Line Items]
Loans	8,776,000		8,642,000
Performing [Member] | Commercial business [Member]
Past due and nonaccrual [Line Items]
Loans	14,444,000		13,996,000
Nonperforming [Member]
Past due and nonaccrual [Line Items]
Loans	42,295,000		3,912,000
Nonperforming [Member] | One-to four- family [Member]
Past due and nonaccrual [Line Items]
Loans	1,283,000		1,143,000
Nonperforming [Member] | Home equity [Member]
Past due and nonaccrual [Line Items]
Loans	642,000		717,000
Nonperforming [Member] | Commercial and multifamily [Member]
Past due and nonaccrual [Line Items]
Loans	240,000		1,347,000
Nonperforming [Member] | Construction and land [Member]
Past due and nonaccrual [Line Items]
Loans	0		471,000
Nonperforming [Member] | Manufactured homes [Member]
Past due and nonaccrual [Line Items]
Loans	0		29,000
Nonperforming [Member] | Other consumer [Member]
Past due and nonaccrual [Line Items]
Loans	3,000		8,000
Nonperforming [Member] | Commercial business [Member]
Past due and nonaccrual [Line Items]
Loans	127,000		197,000
With no related allowance recorded [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	5,562,000	2,972,000
Interest income recognized	49,000	49,000
With no related allowance recorded [Member] | One-to four- family [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	2,341,000	1,731,000
Interest income recognized	10,000	10,000
With no related allowance recorded [Member] | Home equity [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	874,000	542,000
Interest income recognized	3,000	3,000
With no related allowance recorded [Member] | Commercial and multifamily [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	1,328,000	453,000
Interest income recognized	2,000	2,000
With no related allowance recorded [Member] | Construction and land [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	259,000	0
Interest income recognized	0	0
With no related allowance recorded [Member] | Manufactured homes [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	84,000	46,000
Interest income recognized	1,000	1,000
With no related allowance recorded [Member] | Other consumer [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	8,000	55,000
Interest income recognized	0	0
With no related allowance recorded [Member] | Commercial business [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	0		0
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	668,000	147,000
Interest income recognized	33,000	33,000
With an related allowance recorded [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	1,006,000		1,018,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	5,870,000	8,516,000
Interest income recognized	44,000	44,000
With an related allowance recorded [Member] | One-to four- family [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	336,000		392,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	3,820,000	4,135,000
Interest income recognized	30,000	30,000
With an related allowance recorded [Member] | Home equity [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	334,000		247,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	866,000	1,069,000
Interest income recognized	6,000	6,000
With an related allowance recorded [Member] | Commercial and multifamily [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	69,000		70,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	243,000	3,074,000
Interest income recognized	1,000	1,000
With an related allowance recorded [Member] | Construction and land [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	25,000		25,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	76,000	0
Interest income recognized	0	0
With an related allowance recorded [Member] | Manufactured homes [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	107,000		117,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	555,000	72,000
Interest income recognized	3,000	3,000
With an related allowance recorded [Member] | Other consumer [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	27,000		22,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	45,000	35,000
Interest income recognized	0	0
With an related allowance recorded [Member] | Commercial business [Member]
Impaired Financing Receivable, Recorded Investment [Abstract]
Related allowance	108,000		145,000
Impaired Loans, Average Recorded Investment [Abstract]
Average recorded investment	265,000	131,000
Interest income recognized	$ 4,000	$ 4,000