Stockholders' Equity - Net Income (Loss) Attributable to Noncontrolling Interests (Detail) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2022	Mar. 31, 2021	Dec. 31, 2021
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	$ 7,099	$ 3,526
Noncontrolling interests	119,802		$ 102,744
Profits Interest Participation Rights [Member]
Change In Ownership Interest [Line Items]
Noncontrolling interests	5,650		4,049
LFI Consolidated Funds [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	(2,751)	2,268
Noncontrolling interests	79,100		67,299
Edgewater [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	6,988	1,456
Noncontrolling interests	47,485		44,826
LGAC [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	2,860	(200)
Noncontrolling interests	(12,447)		(13,445)
Other [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	2	$ 2
Noncontrolling interests	$ 14		$ 15