Goodwill and Intangible Assets - Additional Information (Detail) - USD ($) $ in Thousands	9 Months Ended
	Sep. 30, 2022	Dec. 31, 2021	Apr. 11, 2018
Indefinite-lived Intangible Assets [Line Items]
Goodwill	$ 85,856	$ 85,856
Intangible asset related to its customary advisory agreement	603,204	$ 601,247
Accumulated Amortization	$ (1)
Software Development [Member]
Indefinite-lived Intangible Assets [Line Items]
Finite lived intangible assets remaining useful lives	3 years
Finite lived intangible assets useful lives	3 years
Accumulated Amortization	$ 1
Acquisition of ETFS Business [Member]
Indefinite-lived Intangible Assets [Line Items]
Goodwill			$ 84,057
Intangible asset related to its customary advisory agreement			$ 601,247
Series of Individually Immaterial Business Acquisitions [Member]
Indefinite-lived Intangible Assets [Line Items]
Acquisition completion date	Apr. 11, 2018