Accrued Expenses (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Payables and Accruals [Abstract]
Payroll and related liabilities	$ 37,396	$ 30,225
Current portion of contingent liabilities	23,760	289
Advances from employees	540	796
Other accrued expenses	34,477	27,622
Total	$ 96,173	$ 58,932