Income Taxes - Schedule of Components of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Significant components of deferred tax assets and liabilities:
Net operating loss	$ 8,397	$ 7,685
Step-up in tax basis in Group LP assets	356,069	208,799
Deferred Compensation	45,875	28,043
Accrued expenses and other	(468)	292
Gross	409,873	244,819
Valuation allowance on NOL and other	(7,014)	(10,819)
Net deferred tax asset	$ 402,859	$ 234,000