Cash and Cash Equivalents (Details) - USD ($) $ in Thousands	Mar. 31, 2019	Dec. 31, 2018	Mar. 31, 2018
Property, Plant and Equipment [Line Items]
Restricted Cash and Cash Equivalents	$ 20,200	$ 21,500
Restricted Cash included in other current assets	2,638	3,100	$ 3,009
Restricted Cash included in other assets	$ 17,567	$ 18,400	$ 21,784