Employee Benefit Plans (Amounts Not Yet Reflected in Net Periodic Benefit Cost and Included in Accumulated Other Comprehensive Loss) (Details) - Employee Pension Plans [Member] - USD ($) $ in Thousands	Dec. 31, 2016	Dec. 31, 2015
Amounts not yet reflected in net periodic benefit cost and included in accumulated other comprehensive loss:
Net actuarial loss	$ (61,132)	$ (56,824)
Cumulative Company contributions in excess of net periodic benefit cost	23,508	23,178
Net amount recognized in Consolidated Balance Sheets	$ (37,624)	$ (33,646)