Accounts Payable, Accrued Expenses and Other Liabilities - Components of Current Portion of Accounts Payable, Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Sep. 30, 2019	Dec. 31, 2018
Accounts Payable Accrued Expenses And Other Liabilities Current [Abstract]
Accounts payable and accrued expenses	$ 142,148	$ 113,713
Redeemable EPUs	93,480
Outside broker payable	65,449	59,918
Payroll taxes payable	56,391	39,620
Corporate and other taxes payable	53,433	77,858
Derivative liability	27,169	16,678
ROU liabilities	25,442
Contingent consideration	10,277	4,452
Total	$ 473,789	$ 312,239