Fair Value - Financial Instruments Measured At Fair Value On A Non-Recurring Basis (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Mar. 31, 2013	Dec. 31, 2012
Single-family residential [Member]
Impaired loans:
Impaired loans at Fair Value	$ 84	$ 57
Impaired loans:
Valuation Technique(s)	Comparable sales approach	Comparable sales approach
Fair Value Inputs, Adjustment for differences between the comparable market transactions	2.30%	2.30%
Multi-family residential [Member]
Impaired loans:
Impaired loans at Fair Value	1,972	2,070
Impaired loans:
Valuation Technique(s)	Comparable sales approach	Comparable sales approach
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(32.70%)	(32.70%)
Non-owner occupied [Member]
Impaired loans:
Impaired loans at Fair Value	1,527	1,806
Impaired loans:
Valuation Technique(s)	Comparable sales approach	Comparable sales approach
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(1.25%)	7.30%
Owner occupied [Member]
Impaired loans:
Impaired loans at Fair Value	1,204	1,244
Impaired loans:
Valuation Technique(s)	Comparable sales approach	Comparable sales approach
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(0.80%)	(0.80%)
Commercial Segment [Member]
Impaired loans:
Impaired loans at Fair Value	$ 121	$ 121
Impaired loans:
Valuation Technique(s)	Income approach	Income approach
Fair Value Inputs, Adjustment for differences in net operating income expectations	(10.00%)	(10.00%)
Minimum [Member] | Multi-family residential [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(39.00%)	(39.00%)
Minimum [Member] | Non-owner occupied [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(9.74%)	(12.20%)
Minimum [Member] | Owner occupied [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(6.30%)	0.50%
Maximum [Member] | Multi-family residential [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	(27.10%)	(27.10%)
Maximum [Member] | Non-owner occupied [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	9.18%	16.70%
Maximum [Member] | Owner occupied [Member]
Impaired loans:
Fair Value Inputs, Adjustment for differences between the comparable market transactions	0.50%	6.30%