Investment Securities Carrying Value (Amortized Cost) and Fair Value by remaining period of contractual maturity (Details) (USD $) In Thousands, unless otherwise specified	Sep. 30, 2013	Mar. 31, 2013
Schedule of Available-for-sale Securities [Line Items]
AFS Amortized Cost One through five years	$ 2,000
AFS Amortized Cost Five through ten years	24,467
AFS Amortized Cost After ten years	65,625
AFS Amortized Cost Total	92,092
AFS Fair Value One through five years	1,984
AFS Fair Value Five through ten years	23,256
AFS Fair Value After ten years	61,982
Available-for-sale, at fair value	87,222	116,051
AFS Weighted Average Rate One through five years	1.50%
AFS Weighted Average Rate Five through ten years	1.95%
Available-for-sale Securities, Debt Maturities, after Ten Years, Weighted Average Rate	2.11%
AFS Weighted Average Rate Total	2.06%
Held-to-Maturity Security Amortized Cost One through Five years	124
HTM Amortized Cost Five through ten years	5,174
HTM Amortized Cost After ten years	7,121
HTM Amortized Cost Total	12,419
Held-to-maturity securities, one through five years, fair value	126
HTM Fair Value Five through ten years	4,903
HTM Fair Value After ten years	7,513
HTM Fair Value Total	$ 12,542
Held-to-maturity Securities, Debt Maturities, One Through Five Years, Weighted Average Rate	3.12%
HTM Weighted Average Rate Five through ten years	2.71%
HTM Weighted Average Rate After ten years	4.00%
HTM Weighted Average Rate Total	3.45%