Variable Interest Entities Text Tag (Details) (USD $)	6 Months Ended
	Sep. 30, 2013	Sep. 30, 2011	Dec. 30, 2010	May 15, 2009	Apr. 28, 2006	Sep. 30, 2013 Carver Statutory Trust 1 [Member]	Sep. 30, 2013 CDE 10 [Member]	Sep. 30, 2013 CDE 1-9, CDE 11-12 [Member]	Dec. 31, 2010 CDE 1-9, CDE 11-12 [Member]
Entity Information [Line Items]
Variable Interest Entity, Funded Exposure, Debt Investment	$ 13,000,000					$ 13,000,000	$ 0	$ 0
Variable Interest Entity, Funded Exposure, Equity Invesment	0					400,000	0	0
% of Carver Statutory Trust I owned	100.00%
Cash			6,700,000
New Market Tax Credit Award		25,000,000		65,000,000	59,000,000
Variable Interest Entity, Rights Transferred	149,000,000			40,000,000		0	19,000,000	40,000,000
Stockholders' Equity Attributable to Noncontrolling Interest									$ 6,700,000