Cover Page - USD ($)	12 Months Ended
	Mar. 31, 2023	Jun. 28, 2023	Sep. 30, 2022
Cover [Abstract]
Document Type	10-K
Document Annual Report	true
Document Transition Report	false
Entity File Number	001-13007
Entity Registrant Name	CARVER BANCORP, INC.
Entity Incorporation, State or Country Code	DE
Entity Address, Address Line One	75 West 125th Street
Entity Address, City or Town	New York
Entity Address, State or Province	NY
Entity Tax Identification Number	13-3904174
Entity Address, Postal Zip Code	10027
City Area Code	(718)
Local Phone Number	230-2900
Entity Well-known Seasoned Issuer	No
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Smaller Reporting Company	true
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 16,905,676
Entity Common Stock, Shares Outstanding		4,441,167
Document Financial Statement Error Correction [Flag]	false