Other Current Assets (Details) - USD ($) $ in Thousands	Dec. 31, 2017	Dec. 31, 2016
Prepaid Expense and Other Assets, Current [Abstract]
Prepaid expenses	$ 29,347	$ 10,276
Sales taxes receivable from customers	2,218	0
Credit Card Receivables	1,008	0
Due from prior owners of acquired businesses for working capital settlements	284	916
Research and development tax credits receivable	0	375
Accrued interest receivable	515	372
Other	160	777
Total	$ 33,532	$ 12,716