Variable Interest Entities Text Tag (Details) - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2013	Mar. 31, 2012	Mar. 31, 2010	Mar. 31, 2007	Mar. 31, 2018
Entity Information [Line Items]
Variable Interest Entity, Funded Exposure, Debt Investment					$ 13,000
Variable Interest Entity, Funded Exposure, Equity Invesment					405
% of Carver Statutory Trust I owned	100.00%
Variable Interest Entity, Rights Transferred					69,500
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount					27,105
New Markets Tax Credit Award		$ 25,000	$ 65,000	$ 59,000
Carver Statutory Trust 1
Entity Information [Line Items]
Variable Interest Entity, Funded Exposure, Debt Investment	$ 13,000				13,000
Variable Interest Entity, Funded Exposure, Equity Invesment	$ 400				400
Variable Interest Entity, Rights Transferred					0
Variable Interest Entity, Reporting Entity Involvement, Maximum Loss Exposure, Amount					$ 0