Cover Page - USD ($) $ in Millions	12 Months Ended
	Mar. 31, 2021	May 26, 2021	Sep. 30, 2020
Document Type	10-K
Document Annual Report	true
Document Period End Date	Mar. 31, 2021
Current Fiscal Year End Date	--03-31
Document Transition Report	false
Entity File Number	001-38021
Entity Registrant Name	HAMILTON LANE INCORPORATED
Entity Incorporation, State or Country Code	DE
Entity Tax Identification Number	26-2482738
Entity Address, Address Line One	One Presidential Blvd.,
Entity Address, Address Line Two	4th Floor
Entity Address, City or Town	Bala Cynwyd,
Entity Address, State or Province	PA
Entity Address, Postal Zip Code	19004
City Area Code	610
Local Phone Number	934-2222
Title of 12(b) Security	Class A Common Stock, $0.001 par value per share
Trading Symbol	HLNE
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 Emerging Growth Company	false
Entity Small Business	false
ICFR Auditor Attestation Flag	true
Entity Shell Company	false
Entity Public Float			$ 1,980.4
Documents Incorporated by Reference	Part III of this Form 10-K incorporates by reference information from the registrant’s definitive proxy statement related to the 2021 annual meeting of stockholders.
Entity Central Index Key	0001433642
Amendment Flag	false
Document Fiscal Year Focus	2021
Document Fiscal Period Focus	FY
Common Class A
Entity Common Stock, Shares Outstanding		36,290,183
Common Class B
Entity Common Stock, Shares Outstanding		16,739,846