Document and Entity Information - shares	9 Months Ended
	Mar. 31, 2022	Apr. 29, 2022
Cover [Abstract]
Document Type	10-Q
Amendment Flag	false
Entity File Number	001-37399
Entity Tax Identification Number	30-0870244
Document Period End Date	Mar. 31, 2022
Document Fiscal Year Focus	2022
Document Fiscal Period Focus	Q3
Trading Symbol	KRNY
Security Exchange Name	NASDAQ
Title of 12(b) Security	Common Stock, $0.01 par value
Entity Registrant Name	KEARNY FINANCIAL CORP.
Entity Central Index Key	0001617242
Current Fiscal Year End Date	--06-30
Entity Filer Category	Large Accelerated Filer
Entity Common Stock, Shares Outstanding		70,421,270
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Address, Address Line One	120 Passaic Ave.
Entity Address, City or Town	Fairfield
Entity Address, State or Province	NJ
Entity Address, Postal Zip Code	07004
Entity Incorporation, State or Country Code	MD
City Area Code	973
Local Phone Number	244-4500
Document Quarterly Report	true
Document Transition Report	false