Loans (Details 5) (USD $) In Thousands, unless otherwise specified	3 Months Ended		12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Dec. 31, 2012
Bank's allowance for loan losses
Beginning balance	$ 10,648	$ 11,262	$ 11,262
Charge off	(523)	(1,717)	(3,684)
Recoveries	78	195	795
Net charge offs	(445)	(1,522)	(2,889)
Provision for loan losses	376	869	2,275
Ending balance	10,579	10,609	10,648
Average loan balance, gross	533,172	562,866	533,081
Ratio of net charge offs to average outstanding loans during the period	0.33%	1.08%	0.52%
One-to-four family mortgages [Member]
Bank's allowance for loan losses
Beginning balance	2,490	2,640	2,640
Charge off	(206)	(122)	(379)
Recoveries	3	39	81
Ending balance	3,148		2,490
Home equity line of credit [Member]
Bank's allowance for loan losses
Beginning balance	374	408	408
Charge off		(53)	(67)
Recoveries	1	1	6
Ending balance	478		374
Junior liens [Member]
Bank's allowance for loan losses
Beginning balance	230	277	277
Charge off	(38)		(1)
Recoveries	23	1	4
Ending balance	118		230
Multi-family [Member]
Bank's allowance for loan losses
Beginning balance	524	1,201	1,201
Charge off			(417)
Recoveries
Ending balance	500		524
Construction [Member]
Bank's allowance for loan losses
Beginning balance	256	139	139
Charge off
Recoveries
Ending balance	131		256
Land [Member]
Bank's allowance for loan losses
Beginning balance	2,184	1,332	1,332
Charge off		(579)	(1,033)
Recoveries	2	100	405
Ending balance	1,454		2,184
Non-residential real estate [Member]
Bank's allowance for loan losses
Beginning balance	3,633	3,671	3,671
Charge off	(123)	(779)	(1,120)
Recoveries	14		137
Ending balance	2,949		3,633
Consumer loans [Member]
Bank's allowance for loan losses
Beginning balance	338	262	262
Charge off	(130)	(108)	(510)
Recoveries	33	52	150
Ending balance	491		338
Commercial loans [Member]
Bank's allowance for loan losses
Beginning balance	619	1,332	1,332
Charge off	(26)	(76)	(157)
Recoveries	2	2	12
Ending balance	$ 1,310		$ 619