Carver Bancorp Inc.-Parent Company Only Parent Company Statements of Financial Condition (Details) - USD ($) $ in Thousands	Mar. 31, 2015	Mar. 31, 2014	Mar. 31, 2013	Mar. 31, 2012	Dec. 30, 2010
Cash					$ 6,700
Other assets	$ 11,266	$ 11,218
Total assets	676,386	639,838
Borrowed Funds	83,403	70,403
Other liabilities	10,243	8,900
Total liabilities	621,407	588,669
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	54,979	51,169	$ 56,735
Total liabilities and equity	676,386	639,838
Parent Company [Member]
Cash	4,679	4,669	$ 4,654	$ 4,775
Investments in and Advance to Affiliates, Subsidiaries, Associates, and Joint Ventures	66,604	62,310
Other assets	54	70
Total assets	71,337	67,049
Borrowed Funds	13,403	13,403
Accounts payable to subsidiaries	1,249	878
Other liabilities	1,706	1,230
Total liabilities	16,358	15,511
Stockholders' Equity, Including Portion Attributable to Noncontrolling Interest	54,979	51,538
Total liabilities and equity	$ 71,337	$ 67,049