Securities: (Details 2) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2013	Mar. 31, 2012
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	$ 40,705	$ 29,285
Unrealized Losses, Less than 12 months	(597)	(241)
Estimated fair value, 12 months or longer	3,941	2,904
Unrealized losses, 12 months or longer	(524)	(530)
Estimated fair value	44,646	32,189
Unrealized losses	(1,121)	(771)
Agency debt securities [Member] | U.S. government and agency securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	14,234	12,317
Unrealized Losses, Less than 12 months	(66)	(83)
Estimated fair value	14,234	12,317
Unrealized losses	(66)	(83)
Taxable municipals [Member] | U.S. government and agency securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	4,441	885
Unrealized Losses, Less than 12 months	(45)	(8)
Estimated fair value	4,441	885
Unrealized losses	(45)	(8)
Tax free municipals [Member] | U.S. government and agency securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	8,510	5,315
Unrealized Losses, Less than 12 months	(126)	(40)
Estimated fair value	8,510	5,315
Unrealized losses	(126)	(40)
Trust preferred securities [Member] | U.S. government and agency securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated fair value, 12 months or longer	1,489	1,489
Unrealized losses, 12 months or longer	(511)	(511)
Estimated fair value	1,489	1,489
Unrealized losses	(511)	(511)
GNMA [Member] | Mortgage-backed securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated fair value, 12 months or longer	1,220	1,415
Unrealized losses, 12 months or longer	(7)	(19)
Estimated fair value	1,220	1,415
Unrealized losses	(7)	(19)
FNMA [Member] | Mortgage-backed securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	9,989	7,077
Unrealized Losses, Less than 12 months	(153)	(58)
Estimated fair value	9,989	7,077
Unrealized losses	(153)	(58)
FHLMC [Member] | Mortgage-backed securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months
Unrealized Losses, Less than 12 months
Estimated fair value, 12 months or longer
Unrealized losses, 12 months or longer
Estimated fair value
Unrealized losses
NON-AGENCY CMOs [Member] | Mortgage-backed securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	1,553
Unrealized Losses, Less than 12 months	(140)
Estimated fair value	1,553
Unrealized losses	(140)
AGENCY CMOs [Member] | Mortgage-backed securities [Member]
Estimated fair value and unrealized loss amounts of temporarily impaired investments
Estimated Fair Value, Less than 12 months	1,978	3,691
Unrealized Losses, Less than 12 months	(67)	(52)
Estimated fair value, 12 months or longer	1,232
Unrealized losses, 12 months or longer	(6)
Estimated fair value	3,210	3,691
Unrealized losses	$ (73)	$ (52)