Stockholders' Equity - Net Income (Loss) Attributable to Noncontrolling Interests and Noncontrolling Interests at the End of the Period (Detail) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2022	Sep. 30, 2021	Sep. 30, 2022	Sep. 30, 2021	Dec. 31, 2021
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	$ 16,995	$ 8,304	$ 20,265	$ 13,568
Noncontrolling interests	116,688		116,688		$ 102,744
Profits Interest Participation Rights [Member]
Change In Ownership Interest [Line Items]
Noncontrolling interests	11,854		11,854		4,049
LFI Consolidated Funds [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	(5,237)	471	(18,393)	5,159
Noncontrolling interests	69,016		69,016		67,299
Edgewater [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	18,209	5,019	28,715	8,349
Noncontrolling interests	46,814		46,814		44,826
LGAC [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests	4,023	2,813	9,941	55
Noncontrolling interests	(11,008)		(11,008)		(13,445)
Other [Member]
Change In Ownership Interest [Line Items]
Net Income (Loss) Attributable to Noncontrolling Interests		$ 1	2	$ 5
Noncontrolling interests	$ 12		$ 12		$ 15