Income Taxes - Reconciliation of Statutory U.S. Federal Income Tax Rate (Detail)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
Statutory U.S. federal income tax rate	21.00%	21.00%	35.00%
Income passed through to noncontrolling interests	(14.68%)	(15.92%)	(11.13%)
Nondeductible amortization of Partner Equity Units	108.30%	(1.09%)	0.73%
State and local income taxes	69.91%	(16.53%)	4.42%
RSU excess deferred income tax write-off	28.58%	(11.33%)	0.50%
Foreign income taxes	42.89%	(6.32%)	0.63%
Income not subject to entity level tax	(19.04%)	4.21%	(4.54%)
Return-to-provision adjustment	(2.41%)	(3.57%)	(0.30%)
Tax effects of income recorded to equity in connection with the Recapitalization	(11.80%)	0.00%	0.00%
Nondeductible transaction costs	15.91%	(3.52%)	0.00%
Nondeductible interest expense	21.54%	0.00%	0.00%
Foreign tax credits and deductions	(11.85%)	(0.77%)	1.88%
Impact of federal tax reform	0.00%	0.00%	40.34%
Other, net	0.15%	(0.50%)	(0.24%)
Effective Income Tax Rate	248.50%	(34.34%)	67.29%