Other Non-current Liabilities (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018
Other Non-current Liabilities [Abstract]
Operating lease liability	$ 93,035
Tax payable	22,438	$ 22,583
Finance lease obligation	10,912	10,146
Other	2,820	9,251
Other non-current liabilities, Total	$ 129,205	$ 41,980