Accrued Expenses and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
ACCRUED EXPENSES AND OTHER CURRENT LIABILITIES [Abstract]
Accrued expenses, current	$ 293,864	$ 301,390
Accrued amounts due to mobile operators and other content providers	65,878	92,291
Money transfer settlement obligations	310,710	343,613
Derivative Liability, Current	36,102	22,495
Accrued expenses and other current liabilities	$ 706,554	$ 759,789