Income Taxes - Reconciliation between Statutory Income Tax Rate and Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Income Tax Disclosure [Abstract]
U.S. Statutory Tax Rate	35.00%	35.00%	35.00%
Increase Due to State and Local Taxes	3.10%	4.80%	7.00%
Rate Benefits as a Limited Liability Company/Flow Through	(2.30%)	(5.90%)	(5.90%)
Foreign Taxes	(1.10%)	0.70%	1.50%
Non-Deductible Expenses	1.60%	9.90%	19.90%
ASU 2016-09 Benefit for Stock Compensation	(5.50%)	(0.00%)	(0.00%)
Tax Cuts and Jobs Act - Reduction to Tax Receivable Agreement Liability	(5.60%)	(0.00%)	(0.00%)
Tax Cuts and Jobs Act - Primarily Related to the Re-measurement of Net Deferred Tax Assets	32.70%	0.00%	0.00%
Valuation Allowances	1.10%	0.00%	0.00%
Other Adjustments	0.10%	(0.00%)	(0.30%)
Effective Income Tax Rate	59.10%	44.50%	57.20%