Stock Transactions and Unit Redemptions - Gross Unit Redemptions and Share Repurchases of Class A Common Stock Table Footnote (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	3 Months Ended		6 Months Ended
	Jun. 30, 2022	Jun. 30, 2021	Jun. 30, 2022	Jun. 30, 2021
Class of Stock [Line Items]
Weighted-average price for redemption of limited partnership units (in dollars per share)	$ 3.84	$ 5.84	$ 3.85	$ 5.83
Aggregate purchase price of Class A common stock			$ 26,408	$ 107,783
Limited Partnership
Class of Stock [Line Items]
Redeemed limited partnership units (in shares)	1,000	4,700	1,000	4,700
Aggregate redemption price of limited partnership units	$ 3,700	$ 27,300	$ 3,800	$ 27,300
FPUs
Class of Stock [Line Items]
Redeemed limited partnership units (in shares)	40	44	100	100
Aggregate redemption price of limited partnership units	$ 100	$ 200	$ 200	$ 200
Weighted-average price for redemption of founding/working partner units (in dollars per share)	$ 2.94	$ 4.06	$ 3.33	$ 4.11
Class A Common Stock
Class of Stock [Line Items]
Common stock, shares issued for redemption/cancellation of units (in shares)	4,700	13,800	7,900	15,400
Common stock, shares issued for exchange of units	700	16,800	4,500	25,900
Stock repurchased during period (in shares)	8,700	16,500		17,500
Aggregate purchase price of Class A common stock	$ 29,400	$ 103,400		$ 107,800
Weighted-average price of Class A common stock (in dollars per share)	$ 3.36	$ 6.25		$ 6.16