Investment Securities Investment Securities-Schedule of Unealized Loss (Details) - USD ($) $ in Thousands		Dec. 31, 2017	Mar. 31, 2017
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		$ 29	$ 1,403
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		3,819	47,162
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		1,708	537
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		50,877	11,446
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,737	1,940
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		54,696	58,608
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		35	60
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		7,968	7,623
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		37	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1,728	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		72	60
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		9,696	7,623
Mortgage-backed securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		29	1,171
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		3,819	34,716
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		992	41
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		29,556	1,942
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		1,021	1,212
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		33,375	36,658
US Government Agency Securities
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0	92
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0	7,482
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		124	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		6,828	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		124	92
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		6,828	7,482
Corporate Bonds
Schedule of Available-for-sale Securities [Line Items]
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		0	140
Available-for-sale Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		0	4,964
Available-for-sale Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		96	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		4,989	0
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss		96	140
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value		4,989	4,964
Other investments
Schedule of Available-for-sale Securities [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]	496	496
Available-for-sale Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value	[1]	9,504	9,504
Available-for-sale Securities, Continuous Unrealized Loss Position, Accumulated Loss	[1]	496	496
Available-for-sale Securities, Continuous Unrealized Loss Position, Fair Value	[1]	9,504	9,504
Mortgage-backed securities
Schedule of Held-to-maturity Securities [Line Items]
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than 12 Months, Accumulated Loss		35	60
Held-to-maturity Securities, Continuous Unrealized Loss Position, Less than Twelve Months, Fair Value		7,968	7,623
Held-to-maturity Securities, Continuous Unrealized Loss Position, 12 Months or Longer, Accumulated Loss		37	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Twelve Months or Longer, Fair Value		1,728	0
Held-to-maturity Securities, Continuous Unrealized Loss Position, Accumulated Loss		72	60
Held-to-maturity Securities, Continuous Unrealized Loss Position, Fair Value		$ 9,696	$ 7,623

[1] (1) Primarily comprised of an investment in a CRA fund with 95% of its underlying investments consisting of government and agency-backed securities.