Investments - Narrative (Detail) - USD ($)	3 Months Ended		9 Months Ended
	Sep. 30, 2023	Sep. 30, 2022	Sep. 30, 2023	Sep. 30, 2022	Dec. 31, 2022
Schedule of Investments [Line Items]
Equity method investments	$ 35,500,000		$ 35,500,000		$ 38,400,000
Gains (losses) on equity method investments	2,094,000	$ 3,230,000	6,568,000	$ 8,762,000
Equity investments carried under measurement alternative	200,000		200,000		200,000
Total assets	3,858,258,000		3,858,258,000		3,074,971,000
Total liabilities	3,002,599,000		3,002,599,000		2,326,244,000
Maximum Exposure to Loss	5,200,000		5,200,000		5,500,000
Other nonoperating income (expense)
Schedule of Investments [Line Items]
Equity investments carried under measurement alternative, loss	0		1,300,000
Equity investments carried under measurement alternative, gain		$ 0		$ 1,900,000
Variable interest entity, primary beneficiary
Schedule of Investments [Line Items]
Total assets	9,100,000		9,100,000		9,200,000
Total liabilities	$ 1,700,000		$ 1,700,000		$ 1,400,000