GOODWILL AND INTANGIBLE ASSETS - Schedule of Goodwill (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Mar. 31, 2023	Dec. 31, 2024	Dec. 31, 2023
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 999,656	$ 1,123,976	$ 999,656
Acquisitions		39,696	124,414
Reallocation		0	0
Foreign currency translation		(1,036)	(94)
Goodwill, ending balance		1,162,636	1,123,976
Credit Group
Goodwill [Roll Forward]
Goodwill, beginning balance	32,196	256,679	32,196
Acquisitions		0	0
Reallocation	224,600	55,658	224,587
Foreign currency translation		(305)	(104)
Goodwill, ending balance		312,032	256,679
Real Assets Group
Goodwill [Roll Forward]
Goodwill, beginning balance	277,183	277,205	277,183
Acquisitions		35,091	22
Reallocation		0	0
Foreign currency translation		(727)	0
Goodwill, ending balance		311,569	277,205
Private Equity Group
Goodwill [Roll Forward]
Goodwill, beginning balance	48,070	172,462	48,070
Acquisitions		4,605	124,392
Reallocation		(55,658)	0
Foreign currency translation		(1)	0
Goodwill, ending balance		121,408	172,462
Secondaries Group
Goodwill [Roll Forward]
Goodwill, beginning balance	417,620	417,630	417,620
Acquisitions		0	0
Reallocation		0	0
Foreign currency translation		(3)	10
Goodwill, ending balance		417,627	417,630
Other
Goodwill [Roll Forward]
Goodwill, beginning balance	$ 224,587	0	224,587
Acquisitions		0	0
Reallocation		0	(224,587)
Foreign currency translation		0	0
Goodwill, ending balance		$ 0	$ 0