Income Taxes - Reconciliation between Statutory Income Tax Rate and Effective Tax Rate (Details)	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Income Tax Disclosure [Abstract]
U.S. Statutory Tax Rate	21.00%	21.00%	35.00%
Increase Due to State and Local Taxes	4.20%	3.60%	3.10%
Rate Benefits as a Limited Liability Company/Flow Through	(2.50%)	(2.60%)	(2.30%)
Foreign Taxes	(0.10%)	0.20%	(1.10%)
Non-Deductible Expenses(1)	1.60%	1.20%	1.60%
ASU 2016-09 Benefit for Stock Compensation	(2.70%)	(4.20%)	(5.50%)
Tax Cuts and Jobs Act - Reduction to Tax Receivable Agreement Liability	0.00%	0.00%	(5.60%)
Tax Cuts and Jobs Act - Primarily Related to the Re-measurement of Net Deferred Tax Assets	0.00%	0.10%	32.70%
Valuation Allowances	0.30%	0.30%	1.10%
Other Adjustments	(0.60%)	0.10%	0.10%
Effective Income Tax Rate	21.20%	19.70%	59.10%