Investments - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Schedule of Equity Method Investments [Line Items]
Total investments		$ 184,700,000	$ 193,900,000
Proceeds from investments		8,000,000	9,500,000	$ 50,900,000
Non Marketable Equity Securities [Member]
Schedule of Equity Method Investments [Line Items]
Total investments		124,000,000	124,000,000
fair value adjustment			39,500,000
Non Marketable Equity Securities [Member] | Series A Convertible Preferred Stock [Member]
Schedule of Equity Method Investments [Line Items]
Number of shares acquired	40,000,000
Investment acquired purchase price	$ 40,000,000
Dividend received		8,000,000	8,000,000	$ 8,000,000
Seed Capital Investments [Member]
Schedule of Equity Method Investments [Line Items]
Total investments		26,100,000	30,600,000
Proceeds from investments		5,700,000	7,600,000
Seed Capital Investments [Member] | Mutual Fund [Member]
Schedule of Equity Method Investments [Line Items]
Total investments			10,000,000
Partnership interests in private equity funds
Schedule of Equity Method Investments [Line Items]
Total investments		11,500,000	15,000,000
Investments, fair value		9,200,000	10,800,000
Equity method investments, fair value		$ 2,300,000	$ 4,200,000