Cover Page - shares	6 Months Ended
	Sep. 30, 2019	Nov. 04, 2019
Document Type	10-Q
Document Quarterly Report	true
Document Period End Date	Sep. 30, 2019
Document Transition Report	false
Entity File Number	001-38021
Entity Registrant Name	HAMILTON LANE INC
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 Current Reporting Status	Yes
Entity Interactive Data Current	Yes
Entity Filer Category	Large Accelerated Filer
Entity Emerging Growth Company	false
Entity Small Business	false
Entity Shell Company	false
Amendment Flag	false
Document Fiscal Year Focus	2020
Document Fiscal Period Focus	Q2
Entity Central Index Key	0001433642
Current Fiscal Year End Date	--03-31
Common Class A
Entity Common Stock, Shares Outstanding		29,824,071
Common Class B
Entity Common Stock, Shares Outstanding		22,049,727