OTHER LONG TERM LIABILITIES (Details) - USD ($) $ in Thousands	Dec. 31, 2020	Dec. 31, 2019
Other Liabilities, Noncurrent [Abstract]
Deferred revenue - long-term	$ 17,434	$ 23,142
Deferred Compensation Liability, Classified, Noncurrent	23,858	20,370
Other Accrued Liabilities, Noncurrent	54,893	36,129
Other Liabilities, Noncurrent, Total	$ 96,185	$ 79,641