Document and Entity Information - USD ($)	12 Months Ended
	Mar. 31, 2021	May 18, 2021	Sep. 30, 2020
Cover [Abstract]
Entity Registrant Name	ePlus inc.
Entity Central Index Key	0001022408
Current Fiscal Year End Date	--03-31
Document Type	10-K
Amendment Flag	false
Document Annual Report	true
Document Period End Date	Mar. 31, 2021
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Document Transition Report	false
Entity File Number	1-34167
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	54-1817218
Entity Address, Address Line One	13595 Dulles Technology Drive
Entity Address, City or Town	Herndon
Entity Address, State or Province	VA
Entity Address, Postal Zip Code	20171-3413
City Area Code	703
Local Phone Number	984-8400
Title of 12(b) Security	Common Stock, $.01 par value
Trading Symbol	PLUS
Security Exchange Name	NASDAQ
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Small Business	false
Entity Emerging Growth Company	false
Entity Shell Company	false
Entity Public Float			$ 967,253,381
Entity Common Stock, Shares Outstanding		13,502,767