Accounts Payable, Accrued Expenses and Other Current Liabilities - Summary of Accounts Payable, Accrued Expenses and Other Current Liabilities (Detail) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Accounts Payable Accrued Liabilities And Other Current Liabilities [Line Items]
Other accrued expenses and current liabilities	$ 24,181	$ 17,032
Accrued payroll and employment related withholding taxes	9,282	24,765
Accrued interest on convertible notes	3,473	5,938
Accrued legal and professional fees	1,091	1,174
Accrued interest on Senior Facility	419
Contingent consideration for acquisitions		420
Total accrued expenses and other current liabilities	39,946	50,829
ABG [Member]
Accounts Payable Accrued Liabilities And Other Current Liabilities [Line Items]
ABG finance liability - current	$ 1,500	$ 1,500