Stock Transactions and Unit Redemptions - Gross Unit Redemptions and Share Repurchases of Class A Common Stock (Detail) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	1 Months Ended			3 Months Ended								12 Months Ended
	Dec. 31, 2023	Nov. 30, 2023	Oct. 31, 2023	Dec. 31, 2023	Sep. 30, 2023	Jun. 30, 2023	Mar. 31, 2023	Dec. 31, 2022	Sep. 30, 2022	Jun. 30, 2022	Mar. 31, 2022	Dec. 31, 2023	Dec. 31, 2022
Equity [Abstract]
Redemptions (in shares)				0	0	422	23	99	214	1,010	43	445	1,366
Repurchases (in shares)	0	1,204	4,269		8,087	9,814	846	5,945	12,397	8,745	0	24,220	27,087
Total redemptions and repurchases (in shares)												24,665	28,453
Redemptions (in dollars per share)				$ 0	$ 0	$ 4.91	$ 3.90	$ 3.88	$ 3.91	$ 3.81	$ 4.01	$ 4.85	$ 3.84
Repurchases (in dollars per share)	$ 0	$ 6.15	$ 5.63		$ 4.99	$ 4.44	$ 4.97	$ 4.14	$ 4.03	$ 3.36	$ 0	4.94	3.84
Total redemptions and repurchases (in dollars per share)												$ 4.93	$ 3.84
Approximate Dollar Value of Shares That Could  Be Repurchased Under the Program at December 31, 2023	$ 333,113			$ 333,113				$ 376,413				$ 333,113	$ 376,413