Investment Securities Investment Securities Unrealized losses and fair value of securities (Details) - USD ($) $ in Thousands		6 Months Ended	12 Months Ended
		Sep. 30, 2015	Mar. 31, 2015
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ (3)	$ (57)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		4,997	12,943
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(858)	(1,090)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		53,719	58,499
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		(861)	(1,147)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		58,716	71,442
Securities Continuous Loss Position Less than 12 months		(30)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(27)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		2,901
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		(27)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		2,901
Securities Continuous Unrealized Loss Position Less than 12 months Fair Value		7,898
Securities, Continuous Unrealized Loss Position ,12 months or Longer		(858)
Securities, Continuous Unrealized Loss Position, 12 months or Longer, Fair Value		53,719
Unrealized Loss on Securities		(888)	(1,147)
Securities, Continuous Unrealized Loss Position, fair value		61,617
Mortgage-backed securities
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(209)	(287)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		17,836	22,297
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		(209)	(287)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		17,836	22,297
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(27)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		2,901
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		(27)
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		2,901
US Government Agency Securities
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		(3)	(57)
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		4,997	12,943
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		(415)	(605)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		26,117	26,400
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		(418)	(662)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		31,114	39,343
Other
Schedule of Investments [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss	[1]	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value	[1]	0	0
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss	[1]	(234)	(198)
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	[1]	9,766	9,802
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	[1]	(234)	(198)
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	[1]	$ 9,766	$ 9,802

[1] (1) CRA fund comprised of over 95% agency securities.