Carver Bancorp Inc.- Parent Company Only-Condensed Statements of Cash Flow (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 1994	Mar. 31, 2023	Mar. 31, 2022	Mar. 31, 2003
Condensed Cash Flow Statements, Captions [Line Items]
Net loss		$ (4,401)	$ (847)
Restricted stock vesting		91	122
Increase (Decrease) in Other Assets		480	(1,301)
Increase (Decrease) in Other Liabilities		(8,432)	7,046
Net cash (used in) provided by operating activities		(10,513)	7,152
Net cash used in investing activities		(15,262)	(79,079)
Proceeds from Issuance of Long-term Debt		25,000	2,500	$ 13,000
Proceeds from Issuance of Common Stock	$ 21,500	0	2,998
Proceeds from Issuance of Preferred Stock		0	4,000
Net cash provided by financing activities		7,309	57,354
Net increase (decrease) in cash and cash equivalents		(18,466)	(14,573)
Parent Company
Condensed Cash Flow Statements, Captions [Line Items]
Net loss		(4,401)	(847)
Equity in net loss from subsidiaries		(2,640)	706
Restricted stock vesting		91	122
Increase in account receivable from subsidiaries		0	(205)
Increase (Decrease) in Other Assets		(57)	92
Increase (decrease) in accounts payable to subsidiaries		976	(1,212)
Increase (Decrease) in Other Liabilities		(14)	(2,593)
Net cash (used in) provided by operating activities		(765)	(4,939)
Capital contribution		0	(15,500)
Net cash used in investing activities		0	(15,500)
Proceeds from Issuance of Long-term Debt		0	2,500
Proceeds from Issuance of Common Stock		0	2,998
Proceeds from Issuance of Preferred Stock		0	4,000
Net cash provided by financing activities		0	9,498
Net increase (decrease) in cash and cash equivalents		(765)	(10,941)
Cash and cash equivalents - beginning		1,433	12,374
Cash and cash equivalents - end		$ 668	$ 1,433