Document and Entity Information - shares	6 Months Ended
	Dec. 31, 2018	Feb. 04, 2019
Document And Entity Information [Abstract]
Document Type	10-Q
Amendment Flag	false
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2019
Document Fiscal Period Focus	Q2
Trading Symbol	KRNY
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		93,101,725
Entity Small Business	false
Entity Emerging Growth Company	false