Investments - Additional Information (Detail) - USD ($)	1 Months Ended	12 Months Ended
	Feb. 29, 2020	Dec. 31, 2024	Dec. 31, 2023	Dec. 31, 2022
Schedule of Equity Method Investments [Line Items]
Total investments		$ 177,400,000	$ 184,700,000
Proceeds from investments		6,900,000	8,000,000	$ 9,500,000
Non Marketable Equity Securities
Schedule of Equity Method Investments [Line Items]
Total investments		124,100,000	124,000,000
Non Marketable Equity Securities | 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
Schedule of Equity Method Investments [Line Items]
Total investments		23,100,000	26,100,000
Proceeds from investments		3,600,000	5,700,000
Partnership interests in private equity funds
Schedule of Equity Method Investments [Line Items]
Total investments		8,600,000	11,500,000
Investments, fair value		7,300,000	9,200,000
Equity method investments, fair value		$ 1,300,000	$ 2,300,000