Investment Securities Unrealized losses and fair value of securities (Details) (USD $) In Thousands, unless otherwise specified	Dec. 31, 2012	Mar. 31, 2012
Total mortgage-backed securities AFS
Gain (Loss) on Investments [Line Items]
Total Fair Value AFS	$ 14,810	$ 13,699
AFS Amortized Cost	34,551	45,782
AFS unrealized losses less than 12 months	(88)	(25)
AFS Fair Value less than 12 months	7,720	13,699
AFS unrealized losses 12 months of longer	(94)	0
AFS Fair Value 12 months or longer	7,090	0
AFS Gross Unrealized Losses	(182)	(25)
Asset-backed Securities [Member]
Gain (Loss) on Investments [Line Items]
AFS Amortized Cost	15,252
AFS Gross Unrealized Losses	0
US Government Agency Securities
Gain (Loss) on Investments [Line Items]
Total Fair Value AFS	4,956	9,917
AFS Amortized Cost	41,983	23,176
AFS unrealized losses less than 12 months	(42)	(63)
AFS Fair Value less than 12 months	4,956	9,917
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	(42)	(63)
Treasuries
Gain (Loss) on Investments [Line Items]
Total Fair Value AFS	1,250	1,555
AFS unrealized losses less than 12 months	0	(1)
AFS Fair Value less than 12 months	1,250	1,555
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	0	(1)
Other
Gain (Loss) on Investments [Line Items]
Total Fair Value AFS		9,973
AFS Amortized Cost	10,691	10,536
AFS unrealized losses less than 12 months		(27)
AFS Fair Value less than 12 months		9,973
AFS unrealized losses 12 months of longer		0
AFS Fair Value 12 months or longer		0
AFS Gross Unrealized Losses	0	(27)
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Total Fair Value AFS	21,016	35,144
AFS unrealized losses less than 12 months	(130)	(116)
AFS Fair Value less than 12 months	13,926	35,144
AFS unrealized losses 12 months of longer	(94)	0
AFS Fair Value 12 months or longer	7,090	0
AFS Gross Unrealized Losses	$ (224)	$ (116)