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, 2021	Mar. 31, 2020
Entity Information [Line Items]
% of Carver Statutory Trust I owned	100.00%
New Markets Tax Credit Award		$ 25,000	$ 65,000	$ 59,000
Accrued interest expense subordinated debt					$ 3,100	$ 2,500
Carver Statutory Trust 1
Entity Information [Line Items]
Variable Interest Entity, Funded Exposure, Debt Investment	$ 13,000				16,110
Variable Interest Entity, Funded Exposure, Equity Invesment	$ 400				$ 400