Loans and Servicing (Details 4) (USD $)	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Recorded Investment
Impaired loans without a valuation allowance	$ 430,000	$ 32,000
Impaired loans with a valuation allowance	2,703,000	3,083,000
Unpaid Principal Balance
Impaired loans without a valuation allowance	430,000	32,000
Impaired loans with a valuation allowance	2,810,000	3,216,000
Related Allowance
Impaired loans with a valuation allowance	240,000	320,000
Average Recorded Investment
Impaired loans without a valuation allowance	331,000	1,351,000
Impaired loans with a valuation allowance	2,987,000	1,711,000
Interest Income Recognized
Impaired loans without a valuation allowance		23,000
Impaired loans with a valuation allowance	30,000	30,000
One- to four- family, residential loans
Recorded Investment
Impaired loans with a valuation allowance	280,000	658,000
Unpaid Principal Balance
Impaired loans with a valuation allowance	280,000	684,000
Related Allowance
Impaired loans with a valuation allowance	14,000	93,000
Average Recorded Investment
Impaired loans without a valuation allowance		176,000
Impaired loans with a valuation allowance	563,000	734,000
Interest Income Recognized
Impaired loans with a valuation allowance	4,000	10,000
Home equity loans and lines of credit
Recorded Investment
Impaired loans without a valuation allowance	430,000	32,000
Impaired loans with a valuation allowance	13,000	13,000
Unpaid Principal Balance
Impaired loans without a valuation allowance	430,000	32,000
Impaired loans with a valuation allowance	13,000	13,000
Related Allowance
Impaired loans with a valuation allowance	13,000	13,000
Average Recorded Investment
Impaired loans without a valuation allowance	331,000	30,000
Impaired loans with a valuation allowance	13,000	13,000
Interest Income Recognized
Impaired loans with a valuation allowance		1,000
Commercial real estate
Recorded Investment
Impaired loans with a valuation allowance	2,410,000	2,412,000
Unpaid Principal Balance
Impaired loans with a valuation allowance	2,517,000	2,519,000
Related Allowance
Impaired loans with a valuation allowance	213,000	214,000
Average Recorded Investment
Impaired loans with a valuation allowance	2,411,000	958,000
Interest Income Recognized
Impaired loans with a valuation allowance	26,000	19,000
Commercial business
Average Recorded Investment
Impaired loans with a valuation allowance		6,000
One-to-four family, construction loans
Average Recorded Investment
Impaired loans without a valuation allowance		801,000
Multi-family
Average Recorded Investment
Impaired loans without a valuation allowance		344,000
Interest Income Recognized
Impaired loans without a valuation allowance		$ 23,000