Operating Segments and Related Information (Details 6) - USD ($) $ in Thousands	Mar. 31, 2018	Dec. 31, 2017
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 1,418,869	$ 1,409,806
United States
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	858,816	797,816
Europe [Member]
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	336,312	343,208
Other Geographic Region [Member]
Business Unit Reporting, Asset Reconciling Item [Line Items]
Long-lived assets	$ 223,741	$ 260,782