Carver Bancorp Inc.-Parent Company Only Parent Company Statements of Income (Details) (USD $) In Thousands, unless otherwise specified	3 Months Ended							12 Months Ended
	Mar. 31, 2014	Sep. 30, 2013	Jun. 30, 2013	Mar. 31, 2013	Dec. 31, 2012	Sep. 30, 2012	Jun. 30, 2012	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012
Interest Expense, Borrowings								$ 1,154	$ 1,370	$ 4,030
Other Expenses								7,735	10,522	11,047
Income / (loss) before income taxes								(844)	45	(23,739)
Income tax expense (benefit)	(8)	(16)	(72)	(64)	(68)	(37)	(159)	102	328	(961)
Net Income (Loss) Attributable to Carver Bancorp, Inc.								(836)	662	(23,407)
Parent Company [Member]
Income (Loss) from Subsidiaries, before Tax								14	1,561	(21,779)
Other Income								29	35	50
Total income (loss)								43	1,596	(21,729)
Interest Expense, Borrowings								450	471	467
Salaries and employee benefits								172	181	272
Shareholder expense								82	99	308
Other Expenses								175	183	631
Total expense								879	934	1,678
Income / (loss) before income taxes								(836)	662	(23,407)
Income tax expense (benefit)								0	0	0
Net Income (Loss) Attributable to Carver Bancorp, Inc.								$ (836)	$ 662	$ (23,407)