Compensation - Compensation Expense Related to Class A Common Stock (Detail) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
LPU amortization	$ 36,708	$ 11,359	$ 1,194
RSU amortization	7,465	5,212	4,576
Equity-based compensation and allocations of net income to limited partnership units and FPUs	165,612	205,070	233,241
LPUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock and exchangeability expenses	100,948	150,147	176,463
Class A Common Stock [Member] | LPUs [Member]
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Issuance of common stock and exchangeability expenses	100,948	150,147	176,463
Allocations of net income1	20,491	38,352	51,008
LPU amortization	36,708	11,359	1,194
RSU amortization	7,465	5,212	4,576
Equity-based compensation and allocations of net income to limited partnership units and FPUs	$ 165,612	$ 205,070	$ 233,241