Investment Securities Text Figures (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	9 Months Ended	12 Months Ended
	Dec. 31, 2012	Dec. 31, 2012	Mar. 31, 2012
Schedule of Investments [Line Items]
Number of securities with unrealized loss		6	14
AFS Fair Value	$ 109,900	$ 109,900
Number of MBS with unrealized loss more than 12 months		2
Held-to-maturity Securities	9,565	9,565	11,081
Percentage Securities in Unrealized Loss More Than 12 months	33.70%
Number of GNMA securities impaired for more than 12 months	2
Available-for-sale Securities [Member]
Schedule of Investments [Line Items]
Percentage Available-for-sale Securities	92.00%	92.00%
Total mortgage-backed securities AFS
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	36.70%	36.70%
US Government Agency Securities
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	23.60%	23.60%
Treasuries
Schedule of Investments [Line Items]
Percentage Available-for-Sale, Continuos Unrealized Loss Position	6.00%	6.00%
Held-to-maturity securities
Schedule of Investments [Line Items]
Percentage Held-to-maturity Securities	8.00%	8.00%
Held-to-maturity Securities	9,600	9,600
Carrying (Reported) Amount, Fair Value Disclosure [Member]
Schedule of Investments [Line Items]
Held-to-maturity Securities			$ 11,081