Consolidated Statements of Shareholders' Equity - USD ($) $ in Thousands	Total	Cumulative-effect adjustment from adoption of accounting guidance	Common Stock Class A Common Stock	Common Stock Class B Common Stock	Additional Paid in Capital	Additional Paid in Capital Cumulative-effect adjustment from adoption of accounting guidance	Retained Earnings	Retained Earnings Cumulative-effect adjustment from adoption of accounting guidance	Accumulated Other Comprehensive Income (Loss)	General Partnerships Noncontrolling Interests	Hamilton Lane Advisors, L.L.C. Noncontrolling Interests	Hamilton Lane Advisors, L.L.C. Noncontrolling Interests Cumulative-effect adjustment from adoption of accounting guidance
Beginning balance at Mar. 31, 2018	$ 136,074	$ 997	$ 22	$ 26	$ 73,829	$ 411	$ 4,549	$ 20	$ 0	$ 7,266	$ 50,382	$ 566
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	98,997						33,573			564	64,860
Other comprehensive income (loss)	15								7		8
Equity-based compensation	6,456				2,912						3,544
Issuance of shares for contingent compensation payout	425		1		200						224
Purchase and retirement of Class A stock for tax withholding	(5,387)				(2,425)						(2,962)
Deferred tax adjustment	10,346				10,346
Dividends declared	(20,456)						(20,456)
Capital contributions from (distributions to) non-controlling interests, net	(2,114)									(2,114)
Member distributions	(55,893)										(55,893)
Offerings adjustment	(2)		4	(2)	9,589						(9,593)
Employee Share Purchase Plan share issuance	264				127						137
Vesting of restricted stock	0				324						(324)
Equity reallocation between controlling and non-controlling interests	0				(2,831)						2,831
Ending balance at Mar. 31, 2019	169,722		27	24	92,482		17,686		7	5,716	53,780
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	126,776						60,825			85	65,866
Other comprehensive income (loss)	(159)								(85)		(74)
Equity-based compensation	7,235				3,830						3,405
Issuance of shares for contingent compensation payout	425				214						211
Purchase and retirement of Class A stock for tax withholding	(5,881)				(3,227)						(2,654)
Deferred tax adjustment	6,526				6,526
Dividends declared	(31,421)						(31,421)
Capital contributions from (distributions to) non-controlling interests, net	(948)									(948)
Member distributions	(36,116)										(36,116)
Offerings adjustment	(2)		3	(2)	6,367						(6,370)
Employee Share Purchase Plan share issuance	1,244				659						585
Vesting of restricted stock	0				333						(333)
Equity reallocation between controlling and non-controlling interests	0				543						(543)
Ending balance at Mar. 31, 2020	237,401		30	22	107,727		47,090		(78)	4,853	77,757
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Net income	167,492						98,022			(250)	69,720
Other comprehensive income (loss)	130								78		52
Equity-based compensation	7,110				4,415						2,695
Issuance of shares for contingent compensation payout	0
Purchase and retirement of Class A stock for tax withholding	(6,019)				(3,935)						(2,084)
Deferred tax adjustment	19,252				19,252
Dividends declared	(42,850)						(42,850)
Capital contributions from (distributions to) non-controlling interests, net	(2,392)									(2,392)
Member distributions	(45,416)										(45,416)
Offerings adjustment	(5)		6	(5)	21,684						(21,690)
Employee Share Purchase Plan share issuance	1,447				900						547
Equity reallocation between controlling and non-controlling interests	0				521						(521)
Accretion of redeemable non-controlling interest	(21,949)						(14,750)				(7,199)
Ending balance at Mar. 31, 2021	$ 314,201		$ 36	$ 17	$ 150,564		$ 87,512		$ 0	$ 2,211	$ 73,861