Document and Entity Information - shares	3 Months Ended
	Mar. 31, 2020	May 05, 2020
Cover Page [Abstract]
Document Type	10-Q
Document Period End Date	Mar. 31, 2020
Entity Registrant Name	Heritage NOLA Bancorp, Inc.
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Non-accelerated Filer
Entity Small Business	true
Entity Emerging Growth Company	true
Entity Ex Transition Period	false
Entity Shell Company	false
Entity Common Stock, Shares Outstanding		1,525,209
Entity Central Index Key	0001700175
Current Fiscal Year End Date	--12-31
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q1