Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Mar. 31, 2021	Mar. 31, 2020	Mar. 31, 2019
Operating activities:
Net income	$ 168,785	$ 126,776	$ 98,997
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation and amortization	4,134	3,291	2,979
Change in deferred income taxes	7,027	7,929	21,665
Change in payable to related parties pursuant to tax receivable agreement	897	(346)	(9,778)
Equity-based compensation	7,079	7,183	6,382
Equity in income of investees	(32,389)	(20,731)	(7,457)
Gain on sale of investments valued under the measurement alternative	0	(4,973)	(11,133)
Fair value adjustment to investment valued under the measurement alternative	(6,229)	(1,507)	0
Proceeds received from investments	784	12,761	14,077
Non-cash lease expense	7,376	4,643	0
Other	1,571	789	190
Changes in operating assets and liabilities:
Fees receivable	1,182	(10,003)	(5,390)
Prepaid expenses	845	(2,272)	(2,414)
Due from related parties	110	23	608
Other assets	(549)	(1,572)	(1,614)
Accounts payable	205	(654)	919
Accrued compensation and benefits	18,611	(987)	4,549
Lease liability	3,105	(5,014)	0
Other liabilities	10,003	556	1,328
Consolidated variable interest entities related:
Net cash provided by operating activities	188,158	116,373	111,622
Investing activities:
Purchase of furniture, fixtures and equipment	(18,637)	(1,978)	(5,366)
Purchase of investments valued under the measurement alternative	(90,500)	(3,967)	0
Distributions received from investments valued under the measurement alternative	3,072
Proceeds from sales of investments valued under the measurement alternative		6,419	22,531
Cash paid for purchase of intangible assets	(1,000)	(4,172)	0
Loan to investee	0	(157)	(944)
Distributions received from partnerships	31,195	7,687	10,614
Contributions to investments	(69,911)	(53,732)	(46,048)
Consolidated variable interest entities related:
Net cash used in investing activities	(421,781)	(49,900)	(19,213)
Financing activities:
Proceeds from offering	473,339	147,122	193,504
Purchase of membership interests	(473,339)	(147,122)	(193,504)
Repayments of long term debt	(1,406)	(71,250)	(2,813)
Borrowings of debt, net of deferred financing costs	75,000	74,765	0
Drawdown of revolver	15,000	15,000	0
Repayment of revolver	0	(15,000)	(10,450)
Secured financing	0	15,750	0
Repurchase of Class B common stock	(5)	(2)	(2)
Repurchase of Class A common stock for employee tax withholding	(6,019)	(5,881)	(5,387)
Proceeds received from issuance of shares under employee stock plans	1,447	1,244	264
Payments to related parties pursuant to the tax receivable agreement	(6,894)	(1,952)	(383)
Dividends paid	(39,676)	(29,067)	(18,676)
Members’ distributions paid	(34,368)	(47,368)	(50,649)
Consolidated variable interest entities related:
Net cash used in financing activities	270,660	(64,709)	(90,210)
Effect of exchange rate changes on cash and cash equivalents	130	(144)	8
Increase (decrease) in cash, cash equivalents, and restricted cash	37,167	1,620	2,207
Cash, cash equivalents, and restricted cash at beginning of year	53,210	51,590	49,383
Cash, cash equivalents, and restricted cash at end of year	90,377	53,210	51,590
Cash, Cash Equivalents, Restricted Cash and Restricted Cash Equivalents [Abstract]
Total cash and cash equivalents, restricted cash, and cash and cash equivalents held at consolidated variable interest entities	53,210	51,590	51,590
Variable Interest Entity
Consolidated variable interest entities related:
Unrealized gain on warrants measured at fair value	(2,141)	0	0
Equity in loss of investees	2,123	481	255
Change in deferred incentive fee revenue	(3,704)	0	(2,541)
Other assets and liabilities	(667)	0	0
Consolidated variable interest entities related:
Purchase of investments held in trust	(276,000)	0	0
Consolidated variable interest entities related:
Contributions from non-controlling interest in general partnerships	252	45	81
Distributions to non-controlling interest in general partnerships	(2,644)	(993)	(2,195)
Proceeds from issuance of Class A units of Hamilton Lane Alliance Holdings I, Inc.	276,000	0	0
Offering costs paid for issuance of Class A units of Hamilton Lane Alliance Holdings I, Inc.	$ (6,027)	$ 0	$ 0