Operating Segments and Related Information (Details 6) - USD ($) $ in Thousands	Jun. 30, 2018	Dec. 31, 2017
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 1,396,667	$ 1,401,806
United States
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	711,292	797,816
Europe [Member]
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	461,800	343,208
Other Geographic Region [Member]
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 223,575	$ 260,782