Investment Securities Unrealized losses and fair value of securities (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended	12 Months Ended
	Jun. 30, 2013	Mar. 31, 2013
Gain (Loss) on Investments [Line Items]
Unrealized Loss on Securities	$ (4,262)	$ (290)
Total securities Estimated Fair Value	130,045	125,680
Total mortgage-backed securities AFS
Gain (Loss) on Investments [Line Items]
AFS unrealized losses less than 12 months	(958)	(104)
AFS Fair Value less than 12 months	33,268	10,298
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	(958)	(104)
Total Fair Value AFS	33,268	10,298
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(303)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	4,848
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(303)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	4,848
US Government Agency Securities
Gain (Loss) on Investments [Line Items]
AFS unrealized losses less than 12 months	(2,667)	(177)
AFS Fair Value less than 12 months	48,038	25,290
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	(2,667)	(177)
Total Fair Value AFS	48,038	25,290
Other
Gain (Loss) on Investments [Line Items]
AFS unrealized losses less than 12 months	(334)	(9)
AFS Fair Value less than 12 months	9,666	9,991
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	(334)	(9)
Total Fair Value AFS	9,666	9,991
Available-for-sale Securities [Member]
Gain (Loss) on Investments [Line Items]
AFS unrealized losses less than 12 months	(3,959)	(290)
AFS Fair Value less than 12 months	90,972	45,579
AFS unrealized losses 12 months of longer	0	0
AFS Fair Value 12 months or longer	0	0
AFS Gross Unrealized Losses	(3,959)	(290)
Total Fair Value AFS	90,972	45,579
Held-to-maturity Securities [Member]
Gain (Loss) on Investments [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Aggregate Losses	(303)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	4,848
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Aggregate Losses	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Aggregate Losses	(303)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value	4,848
Debt Securities [Member]
Gain (Loss) on Investments [Line Items]
Securities Continuous Loss Position Less than 12 months	(4,262)
Securities Continuous Unrealized Loss Position Less than 12 months Fair Value	95,820
Securities, Continuous Unrealized Loss Position ,12 months or Longer	0
Securities, Continuous Unrealized Loss Position, 12 months or Longer, Fair Value	0
Unrealized Loss on Securities	(4,262)
Total securities Estimated Fair Value	$ 95,820