Accounts Payable, Accrued Expenses and Other Liabilities - Components of Current Portion of Accounts Payable, Accrued Expenses and Other Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Payables and Accruals [Abstract]
Accounts payable and accrued expenses	$ 97,304	$ 161,988
Outside broker payable	53,504	74,280
Payroll taxes payable	60,696	45,612
Corporate taxes payable	25,666	69,237
Derivative liability	17,948	25,661
Right-of-use liabilities	29,468	27,184
Credit enhancement deposit	25,000	0
Contingent consideration	16,962	13,107
Total	$ 326,548	$ 417,069